HVAC System Analysis

Berkeley County School District

RMF ENGINEERING, INC. 7/29/2013

RMF performed a HVAC system study with an overview of various system configurations. The study includes energy and life cycle cost analysis for various HVAC system configurations in order to determine the most cost effective HVAC system for Berkeley County School Districts new construction projects.

BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

TABLE OF CONTENTS

DIVISION 1 - EXECUTIVE SUMMARY ...... 1 1.1 INTRODUCTION ...... 1 1.2 OBJECTIVE ...... 1 1.3 RESULTS ...... 1 1.4 HUMIDITY CONTROL ...... 2 1.5 CONCLUSION ...... 3

DIVISION 2 - INTRODUCTION ...... 4 2.1 PURPOSE ...... 4 2.2 PROJECT DESCRIPTION ...... 4 2.3 HUMIDITY CONTROL ...... 5 2.4 DESIGN CRITERIA ...... 7 2.5 BUILDING DESCRIPTION ...... 9 2.6 HVAC SYSTEM DESCRIPTIONS ...... 9

DIVISION 3 - SYSTEMS ANALYSIS ...... 19 3.1 GENERAL ...... 19 3.2 WEATHER ...... 19 3.3 ENVELOPE ...... 19 3.4 SCHEDULES ...... 21 3.5 INTERIOR DESIGN CONDITIONS ...... 22 3.6 UTILITY RATES ...... 23 3.7 HVAC SYSTEMS...... 24

DIVISION 4 - LIFE CYCLE COST ANALYSIS ...... 29 4.1 ANALYSIS ...... 29 4.2 RESULTS ...... 29

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BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

DIVISION 5 - APPENDICES ...... 30 5.1 DEDICATED OUTDOOR AIR SYSTEM CONFIGURATION ...... 30 5.2 BUILDING ARCHITECTURE ...... 30 5.3 EQUEST INPUTS ...... 30 5.4 UTILITY RATES ...... 30 5.5 OUTPUT REPORTS ...... 30 5.6 FIRST COST CALCULATIONS ...... 30 5.7 LIFE CYCLE COST ANALYSIS CALCULATIONS ...... 30 5.8 RMF MEMO FOR CANE BAY ELEMENTARY SCHOOL HVAC SYSTEM CONFIGURATION .... 30 5.9 FIRM BACKGROUND ...... 30

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BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

DIVISION 1 - EXECUTIVE SUMMARY

1.1 INTRODUCTION

A. Berkeley County School District (BCSD) recently passed a bond referendum that includes building five (5) new schools. Studies have shown that during the schematic design phase less than one (1%) percent of a projects soft cost are used to determine up to seventy (70%) percent of a buildings life cycle cost. One of the most important project components to ensure a productive and comfortable learning environment as well as control energy costs is the selection of the Heating, Ventilation and Air Conditioning (HVAC) system.

B. In August 2012, BCSD opened Cane Bay Middle School with the preferred 4 pipe, individual fan coil units (FCU) system with ice storage. However, with the adoption of the 2012 International Code Council (ICC) building codes and 2009 ICC Energy Code in January 2013, the Cane Bay Middle School system configuration no longer meets code as discussed in RMF’s letter dated March 20, 2013 which is located in the Appendix. Since a new HVAC system configuration was necessary in order to incorporate all of the requirements of the 2009 Energy Code as well as the new IBC 2012 code, it was determined that several systems should be analyzed in order to select the best HVAC system based upon analytical data specific to the school district.

1.2 OBJECTIVE

A. BCSD commissioned RMF to conduct a study of various HVAC systems with the focus on equipment first (installed) cost, yearly maintenance, equipment replacement, annual energy costs and the ease of maintenance. The results of this study will allow BCSD to select the HVAC system which will be the most cost effective over a 20 year period of time. The most cost effective HVAC system will be used in BCSD’s future schools.

B. RMF created energy models using eQUEST software in order to analyze the proposed HVAC systems energy consumption. RMF used the energy models to develop a 20 year Life Cycle Cost Analysis (LCCA) which incorporated equipment first (installed) cost, yearly maintenance, equipment replacement and energy costs in order to determine the most cost effective HVAC system for Berkeley County School Districts new construction projects.

1.3 RESULTS

A. For the modeled building architecture, HVAC configuration System 4 - Water Source Heat Pump System had the lowest annual energy cost. System 4 uses 44.3% less energy (MBH) than any other modeled system. Refer to the BEPS reports in section 4.5 of the Appendix for additional information. The large difference in energy usage is due to the inherent energy recovery capability of the water source heat pump system. Due to the heat produced by occupants and equipment, the mild climate of Berkeley County and

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the fact that heat is either rejected to or removed from the water source loop, minimal heating energy is required to be added to System 4. For a full description of each modeled system type refer to Division 2 of this report. The annual energy usage for the four (4) system types that were modeled can be seen in the table below. A fifth system, variable refrigerant flow energy recovery fan coil system with a decoupled air cooled direct expansion refrigerant outdoor air system, was not modeled as it was determined that it was not easily maintainable and was not compatible with the school districts desired building architecture and site layout.

ENERGY COSTS: Electric Usage Natural Gas Total Charge * System (kW/h) Usage (Therm) ($) System 1: FCU w/Ice Storage 627 ,667 9,63 2 $157,452 System 2: FCU w/o Ice Storage 498,767 9,630 $1 45 ,972 System 3: FCU w/Turbocor Chiller 405 ,799 9,630 $1 37 ,09 7 System 4: Water Source Heat Pump 383 ,231 6 $1 20 ,871

*Total Charge includes all costs associated with the modeled buildings energy usage.

B. The life cycle cost analysis, including a sensitivity analysis conducted in regards to changes in electrical rates, proves conclusively that for the modeled building architecture and HVAC configuration the water source heat pump system has the lowest annual life cycle cost. The annual energy usage for the four (4) system types that were modeled can be seen in the table below.

LIFE CYCLE COSTS: Capital Cost First Year Life Cycle Cost System ($) Annual Cost ($) ($) System 1: FCU w/Ice Storage $2,523,940 $165,359 $5,423,740 System 2: FCU w/o Ice Storage $2,371,356 $153,380 $5,058,456 System 3: FCU w/Turbocor Chiller $2,490,496 $144,504 $5,018,896 System 4: Water Source Heat Pump $1,748,630 $126,772 $4,362,030

System 4 – Water Source Heat pump has the lowest 20 year life cycle cost of $4,362,030 which is 13.8% less expensive than any other system studied.

1.4 HUMIDITY CONTROL

A. Controlling the humidity, the amount of water vapor contained in air, is of great concern due to the warm humid climate of Berkeley County, particularly during the months of May through October. Excessive humidity can make a room feel uncomfortable even though the space temperature is within the design range. When not properly

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controlled, high humidity levels can also lead to the growth of mold and mildew, and cause degradation of the facility and equipment through rust and corrosion. Not only does the HVAC system need to address humidity control but the building occupants must also be vigilant in keeping windows and doors closed. Most HVAC systems would take many hours to recover from indoor humidity conditions far above design and utilizing HVAC systems just to control humidity due to open doors and windows will require a large amount of wasted energy.

B. Humidity control is an integral part of the decoupled water source heat pump system and is primarily accomplished through the Dedicated Outdoor Air Units and to a lesser extent by the individual fan coil units. When the ventilation air enters the dedicated outdoor air unit, the air is pre-cooled by a plate and frame total enthalpy heat exchanger which rejects heat to the cooler exhaust air. The cool dry air discharged from the dedicated outside air units is then separately ducted to each individual room. Additionally, when the air in the room passes through the fan coil unit in cooling mode, any water vapor condenses and is piped away as part of the condensate system. Humidistats which measure humidity levels will be located throughout the building to monitor and adjust humidity levels. Since it is not cost effective to put humidistats in every room, it would be a collective decision between the designer and Owner as to the location and number of humidistats. Densely occupied areas such as conference rooms, multipurpose rooms and Media Centers would require humidistats due to the high occupancy loads and to prevent humidity damage to books, magazines, etc.

1.5 CONCLUSION

A. The Water Source Heat Pump System (System 4) has: 1. The lowest overall annual energy costs 2. The lowest life cycle costs 3. The lowest maintenance costs 4. The greatest ease of maintenance 5. The best individual control of the learning environment since there is one fan coil unit for each classroom 6. The least amount of disruption for repairs. When one unit is down it only affects the space it serves.

Based on the information above, the water source heat pump system is recommended to be used for future BCSD school projects.

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DIVISION 2 - INTRODUCTION

2.1 PURPOSE

A. Berkeley County School District (BCSD) tasked RMF to perform an energy analysis of multiple HVAC systems types and to use the results to complete a life cycle cost analysis for each system in order to help determine the most appropriate HVAC system to be used in future school construction.

B. Systems to study were selected based on the ability to provide thermal comfort control to individual classrooms. It has been found over time that when a single HVAC unit provides service to multiple classrooms it has detrimental effects on the learning environment in the classrooms due to lack of thermal control. Additionally, whenever a unit needs service or repair, multiple classrooms are disrupted. Ensuring comfortable learning environments in each individual classroom is of highest priority, therefore, having a single unit for each classroom is a preferred feature of the HVAC systems. Additionally the type of systems that were selected for the study are currently performing well at existing schools in the district and are easy to maintain.

2.2 PROJECT DESCRIPTION

A. RMF performed a HVAC system study with an overview of various HVAC system configurations which included system benefits and deficiencies. The study also includes energy and life cycle cost analysis for four (4) HVAC system configurations. A fifth system, variable refrigerant flow energy recovery fan coil system with a decoupled air cooled direct expansion refrigerant outdoor air system, was not modeled as it was determined that it was not easily maintainable and was not compatible with the school districts desired building architecture and site layout.

B. RMF created energy models using eQUEST software. The models incorporated usage and demand charges from Berkeley Electric Co-op for electric power and usage charges from SCE&G for natural gas. 1. System 1: Four-pipe fan coil system with a decoupled four-pipe outdoor air system. Air cooled chillers with ice storage to generate chilled water. Gas fired condensing boilers to generate heating water. 2. System 2: Four-pipe fan coil system with a decoupled four-pipe outdoor air system. Air cooled chillers without ice storage to generate chilled water. Gas fired condensing boilers to generate heating water. 3. System 3: Four-pipe fan coil system with a decoupled four-pipe outdoor air system. Magnetically levitated bearing centrifugal chiller (Turbocor Compressor) without ice storage to generate chilled water. Gas fired condensing boilers to generate heating water.

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4. System 4: Water source heat pump fan coil system with a decoupled water source outdoor air system. Closed circuit cooling tower and gas fired condensing boilers to generate condenser water. 5. All energy models were based on the architecture and HVAC loads of Nexton Elementary School.

C. RMF developed a 20 year Life Cycle Cost Analysis (LCCA) which incorporated equipment first (installed) cost, yearly maintenance, equipment replacement and energy costs. 1. Life cycle costs were broken out to show installed costs, first year utility cost and first year maintenance cost. 2. Life cycle cost included a utility rate sensitivity analysis based on Berkeley Electric Co-ops and SCE&G’s projection of rate increases.

2.3 HUMIDITY CONTROL

A. It is the preference of the Berkeley County School district to use an individual fan coil unit system (versus central station air handlers with variable volume terminal units) in order to meet the space sensible heating and cooling requirements. The occupant density in classrooms results in increased amounts of required ventilation air, therefore, a dedicated outdoor air system (DOAS) is needed to decouple the outdoor air load from the space sensible load in order to provide humidity control.

B. Inadequate humidity control and high space relative humidity has the potential to lead to surface moisture/condensation, toxic mold, microbial growth and possibly even “sick building syndrome” if left untreated. Besides the effect on comfort and health, high indoor humidity levels can also damage a building’s furnishings and mechanical systems, even its structure, leaving Berkeley County School District with considerable maintenance or renovation expense.

C. Indoor Relative Humidity Set Point: 1. ANSI/ASHRAE Standard 55, Thermal Environmental Conditions for Human Occupancy, specifies thermal environmental conditions that are acceptable to 80 percent or more of the occupants within a space. The “comfort zone” defined by Standard 55 represents a range of environmental conditions based on dry-bulb temperature, humidity, thermal radiation, and air movement. Depending on the utility of the space, maintaining the relative humidity between 30% and 60% keeps most occupants comfortable. 2. ANSI/ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality, addresses the link between indoor moisture and microbial growth by stating that relative humidity in habitable spaces should be maintained between 30% and 60% to minimize the growth of allergenic and pathogenic organisms. To control microorganisms, it is best to keep relative humidity below 60% (to control mold) and 50% (to control dust mites) at all times, including unoccupied hours.

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3. The U.S. Environmental Protection Agency (EPA) adopts a similar stance in its publication (EPA 402-K-01-001) titled Mold Remediation in Schools and Commercial Buildings, by stating that the key to mold control is moisture control, and that one way to help prevent mold is to maintain low indoor humidity, below 60% relative humidity, ideally 30–50%. 4. Standard engineering practice for classroom HVAC design, one that RMF recommends, is to design for an indoor condition of 50% relative humidity, which allows for some fluctuation of humidity levels based on ambient conditions, infiltration, HVAC equipment and building controls without exceeding the recommended maximums for thermal and environmental control.

D. Dehumidification of Ventilation Air 1. ANSI/ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality, requires the HVAC system to continuously provide a minimum ventilation rate of 10 cfm/person and 0.12 cfm/ft2 in classrooms. This standard has been adopted by the International Mechanical Code and dictates the quantity of outdoor air required for the classrooms that must be provided to each regularly occupied space. 2. Conventional, mass produced fan coil units, which have limited cooling coil options (rows, fins/inch, tubing size) for a particular fan coil unit size are typically designed to maintain the dry-bulb temperature (temperature) in the space and not the wet-bulb temperature (moisture). During most of the year a fan coil unit will operate in part load conditions, where the sensible cooling loads are considerably less than the peak design conditions the unit was selected for. Because constant-volume systems respond to part-load conditions by reducing coil capacity (which raises the temperature of the coil surface and of the supply air), the coil surface will not be colder than the dew point and sensible cooling without dehumidification will occur. This means that humidity levels cannot be closely controlled.

E. The more demanding application of the Nexton Elementary School (densely occupied classroom spaces in a southern, humid climate) requires an enhanced design to adequately manage and limit indoor humidity. A properly designed and controlled DOAS should be provided to decouple the space sensible and latent loads, and accommodate all of the ventilation and space latent loads; therefore providing the capability to limit occupied space relative humidity to the recommended maximum 50% or less at peak outdoor dew point design conditions. In addition, the DOAS would be able to accurately maintain the building at net positive pressure with respect to outdoors during all hours of dehumidification, provide the make-up air necessary for any exhaust intensive applications within the building, and reduce yearly energy consumption by capturing energy from the exhaust airstream.

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2.4 DESIGN CRITERIA

A. Codes and Standards 1. All mechanical and lighting systems shall be modeled to comply with the following codes and standards: a. 2012 International Mechanical Code (IMC) b. 2012 International Building Code (IBC) c. 2009 International Energy Conservation Code (IECC) d. ASHRAE 90.1-2007 e. South Carolina School Planning and Construction Guide, Office of School Facilities (OSF) - 2013 f. Berkeley County School District Design Guidelines

B. The heating, ventilating and air conditioning (HVAC) systems shall be designed to produce the desired space temperature, humidity, pressurization and air quality conditions while employing the following design criteria.

C. Outdoor Ambient Conditions 1. The cooling design values are based on 1% annual cumulative frequency of occurrence and the heating, humidification and wind design values are based on 99% annual cumulative frequency of occurrence.

Summer Winter Design Temperature, Dry Bulb 92°F 31 °F Design Temperature, Wet Bulb 78°F -- Mean Wind Speed 10 MPH 7.2 MPH Prevailing Wind Direction 240° True (from 20° True (from the the WSW) N)

D. Indoor Design Conditions 1. The following indoor design temperature and humidity conditions are required for all interior program spaces. Temperature shall be controlled to plus/minus 2°F and humidity to plus/minus 5% RH from the stated values. When a max or min value is noted, that implies the limit of system operability.

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Program Space Summer Winter Setback Classrooms 75° F / 50%RH 70 °F 80 °F / 58 °F Administration 75° F / 50%RH 70 °F 80 °F / 58 °F Cafeteria 75° F / 50%RH 70 °F 80 °F / 58 °F Multi -Purpose 75° F / 50%RH 70 °F 80 °F / 58 °F Corridor s 75° F / 50%RH 70 °F 80 °F / 58 °F Kitchen 75° F / 50%RH 70 °F 80 °F / 58 °F Media 75° F / 50%RH 70 °F 80 °F / 58 °F Mechanical Rooms 80 °F / 50%RH 60°F - Electrical Roo ms 80 °F / 50%RH 60°F (Note 1) - (Note 1) IT Rooms 80°F / 50%RH 60°F -

Note 1: Rooms less than 60 SF with no heat producing equipment, such as transformers and electronic panels with data processing boards, shall not be heated, cooled or ventilated. Note 2: Rooms shall be provided with an independent air-conditioning system to protect against the overheating of electrical equipment.

E. Ventilation Criteria: 1. Ventilation rates shall be modeled in accordance with ASHRAE Standard 62.1 – 2007, “Ventilation for Acceptable Indoor Air Quality” and calculated using the Ventilation Rate Procedure. The occupancy density shall be based on the formal program for the facility, the furniture/seating layout or the printed ASHRAE values whichever is greater.

F. Exhaust Criteria 1. Exhaust airflow shall be provided in accordance with ASHRAE Standard 62.1 – 2007 and the following table. Exhaust makeup air may be any combination of outdoor air, recirculated air and transfer air.

Program Occupancy Exhaust Rate CFM/ft 2

Janitor, trash, recycle rooms 1.00 Toilets 75 CFM/water closet or urinal

G. Pressurization Criteria

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1. Building air systems shall be balanced to achieve positive building pressure and minimize infiltration. Air handling systems shall return and/or exhaust approximately 7.5% less air than they are supplied to ensure a positively pressurized building.

H. Building Operating Schedule 1. Programmable system shutdown and night setback modes for selected areas shall be provided for all fan coil units, air handling units and dedicated outdoor air systems to reduce energy use during periods of non-use.

I. Internal Heat Gains 1. Equipment heat gains and occupancy loads for general use spaces shall be as defined by the programming documents and Owner furnished load criteria. Equipment loads are derived from the equipment listed in the program. Lighting loads shall be based on the design standards defined hereinafter and the minimum requirements of ASHRAE 90.1-2007.

2.5 BUILDING DESCRIPTION

A. The modeled school is based upon Nexton Elementary and is an approximately 108,000 square foot one story building designed to hold 900 students. The school construction is made of a masonry exterior wall system, structural steel framing system and a standing seam metal roof. The exterior wall system contains three (3) inches and the standing seam metal roof contains four (4) inches of continuous rigid insulation. The exterior window and curtain wall systems are comprised of aluminum frames with high performance glazing. The interior walls are generally constructed of hollow masonry wall units.

2.6 HVAC SYSTEM DESCRIPTIONS

A. It is the preference of BCSD to use individual fan coil systems. Outdoor air for ventilation and humidity control shall be provided by dedicated outside air units (DOAU) with total energy enthalpy plate and frame heat exchanger and a sensible plate and frame heat exchanger. The proposed system types are: 1. System 1: Chilled and Heating Water Fan Coil Units (with Ice Storage) a. Building Heating Water System 1) Heating water shall be provided for fan coil and dedicated outdoor air unit heating coils. A variable speed, variable flow primary heating water pumping system shall be utilized for the distribution of heating water with all heating coil control valves being 2-way for variable flow pumping. 2) Two (2) natural gas fired, high-efficiency, condensing heating water boilers shall generate 160°F supply heating water. Each boiler shall

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be sized at 50% of the total building heating load. The basis of design shall be Aerco Benchmark. 3) Two (2) variable volume end suction primary heating water pumps shall circulate the heating water through the gas-fired heating water boilers and the building heating water coils. Each pump shall be sized at 50% of the total heating load, and will have variable frequency drives to match the required water flow to the building load. 4) The heating water system shall be modeled with a 30°F temperature difference (160°F to 130°F) and will be operated on an adjustable proportional reset schedule based on outdoor temperature to maximize energy efficiency. b. Building Chilled Water System 1) The building chilled water system shall provide chilled water for the building fan coil and dedicated outdoor air unit chilled water coils. A variable primary chilled water pumping system with ice storage shall be modeled for the distribution of chilled water, with all cooling coil control valves being 2-way for variable flow pumping. 2) Two (2) electric air-cooled centrifugal chillers shall generate chilled water at a temperature dependent on the operating mode. In “ice build” the chillers shall run at 100% capacity until a return water temperature of 21 °F is sensed. In all other modes the combination of chiller operation and ice melt shall produce 40°F leaving water temperature. Each chiller shall be sized for 50% of the building chilled water load. The basis of design for the centrifugal chillers shall be Trane RTAC. 3) Two (2) end suction constant speed primary glycol water pumps shall circulate glycol water through the chillers, ice storage tanks and plate heat exchanger. Each primary pump shall be sized for 50% of the building chilled water load. 4) Two (2) end suction variable speed primary chilled water pumps shall circulate chilled water through the building chilled water coils and plate heat exchanger. Each primary pump shall be sized for 50% of the building chilled water load. 5) The chilled water system shall be modeled with a 14°F temperature difference (54°F to 40°F). c. Fan Coil Units 1) The blower coil units shall provide 100% recirculated air to meet the space sensible heating and cooling requirements. The blower coil shall be a packaged factory unit with a chilled water coil, heating

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water coil and ECM motor. The basis of design for the fan coil units is Trane model BCVC. d. Outdoor Air Units 1) The dedicated outdoor air handling units shall provide 100% OA outdoor air to meet the nominal ventilating criteria, provide make- up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling unit shall be a custom unit with heating water coil, chilled water coil, total energy enthalpy plate and frame heat exchanger and a sensible plate and frame heat exchanger. The basis of design for the outdoor air units is Annexair. 2. System 2: Chilled and Heating Water Fan Coil Units (without Ice Storage) a. Building Heating Water System 1) Heating water shall be provided for fan coil and dedicated outdoor air unit heating coils. A variable speed, variable flow primary heating water pumping system shall be utilized for the distribution of heating water with all heating coil control valves being 2-way for variable flow pumping. 2) Two (2) natural gas fired, high-efficiency, condensing heating water boilers shall generate 160°F supply heating water. Each boiler shall be sized at 50% of the total building heating load. The basis of design shall be Aerco Benchmark. 3) Two (2) variable volume end suction primary heating water pumps shall circulate the heating water through the gas-fired heating water boilers and the building heating water coils. Each pump shall be sized at 50% of the total heating load, and will have variable frequency drives to match the required water flow to the building load. 4) The heating water system shall be modeled with a 30°F temperature difference (160°F to 130°F) and will be operated on an adjustable proportional reset schedule based on outdoor temperature to maximize energy efficiency. b. Building Chilled Water System 1) The building chilled water system shall provide chilled water for the building fan coil and dedicated outdoor air unit chilled water coils. A variable primary chilled water pumping system shall be modeled for the distribution of chilled water, with all cooling coil control valves being 2-way for variable flow pumping. 2) Two (2) electric air-cooled centrifugal chillers shall generate chilled water design temperatures of 40°F supply with a 54°F return. Each

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chiller shall be sized for 50% of the building chilled water load. The basis of design for the centrifugal chillers shall be Trane RTAC. 3) Two (2) end suction variable speed primary chilled water pumps shall circulate chilled water through the chillers and the building chilled water coils. Each primary pump shall be sized for 50% of the building chilled water load. 4) The chilled water system shall be modeled with a 14°F temperature difference (54°F to 40°F). c. Fan Coil Units 1) The blower coil units shall provide 100% recirculated air to meet the space sensible heating and cooling requirements. The blower coil shall be a packaged factory unit with a chilled water coil, heating water coil and ECM motor. The basis of design for the fan coil units is Trane model BCVC. d. Outdoor Air Units 1) The dedicated outdoor air handling units shall provide 100% OA outdoor air to meet the nominal ventilating criteria, provide make- up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling unit shall be a custom unit with heating water coil, chilled water coil, total energy enthalpy plate and frame heat exchanger and a sensible plate and frame heat exchanger. The basis of design for the outdoor air units is Annexair. 3. System 3: Chilled and Heating Water Fan Coil Units (High Efficiency Chiller) a. Building Heating Water System 1) Heating water shall be provided for fan coil and dedicated outdoor air unit heating coils. A variable speed, variable flow primary heating water pumping system shall be utilized for the distribution of heating water with all heating coil control valves being 2-way for variable flow pumping. 2) Two (2) natural gas fired, high-efficiency, condensing heating water boilers shall generate 160°F supply heating water. Each boiler shall be sized at 50% of the total building heating load. The basis of design shall be Aerco Benchmark. 3) Two (2) variable volume end suction primary heating water pumps shall circulate the heating water through the gas-fired heating water boilers and the building heating water coils. Each pump shall be sized at 50% of the total heating load, and will have variable frequency drives to match the required water flow to the building load.

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4) The heating water system shall be modeled with a 30°F temperature difference (160°F to 130°F) and will be operated on an adjustable proportional reset schedule based on outdoor temperature to maximize energy efficiency. b. Building Chilled Water System 1) The building chilled water system shall provide chilled water for the building fan coil and dedicated outdoor air unit chilled water coils. A variable primary chilled water pumping system shall be modeled for the distribution of chilled water, with all cooling coil control valves being 2-way for variable flow pumping. 2) Two (2) magnetically levitated bearing air-cooled centrifugal chillers (Turbocor Compressor) shall generate chilled water design temperatures of 40°F supply with a 54°F return. Each chiller shall be sized for 50% of the building chilled water load. The basis of design for the magnetically levitated bearing centrifugal chillers shall be Smardt. 3) Two (2) end suction variable speed primary chilled water pumps shall circulate chilled water through the chillers and the building chilled water coils. Each primary pump shall be sized for 50% of the building chilled water load. 4) The chilled water system shall be modeled with a 14°F temperature difference (54°F to 40°F). c. Fan Coil Units 1) The blower coil units shall provide 100% recirculated air to meet the space sensible heating and cooling requirements. The blower coil shall be a packaged factory unit with a chilled water coil, heating water coil and ECM motor. The basis of design for the fan coil units is Trane model BCVC. d. Outdoor Air Units 1) The dedicated outdoor air handling units shall provide 100% OA outdoor air to meet the nominal ventilating criteria, provide make- up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling unit shall be a custom unit with heating water coil, chilled water coil, total energy enthalpy plate and frame heat exchanger and a sensible plate and frame heat exchanger. The basis of design for the outdoor air units is Annexair. 4. System 4: Water Source Heat Pump Units a. Building Water Source Condenser Water System 1) The system shall be comprised of highly efficient packaged reverse cycle heat pump units served by a condenser water loop. In hot

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weather, when most or all of the units are operating in the cooling mode, heat shall be rejected via the unit's refrigerant-to-water coaxial heat exchanger into the condenser water loop. If not required somewhere else in the building, the heat shall be rejected from the building through an external fluid cooler to maintain a maximum temperature of 85°F in the water loop. In cold weather, the heat pump shall remove heat from the water loop via the unit's refrigerant-to-water coaxial heat exchanger. 2) Two (2) natural gas fired, high-efficiency, condensing heating water boilers shall maintain a minimum temperature of 60 °F in the water loop during high heating demand months. Each boiler shall be sized for 50% of the building heat load. The basis of design shall be Aerco Benchmark. 3) One (1) dual cell counterflow closed circuit cooler with axial fan design and vertical air discharge shall provide condenser water design temperatures of 85 degree Fahrenheit supply with a 95 degree Fahrenheit return with a 5 degree approach. The tower shall be provided with a variable frequency drive (VFD) for fan speed control. Each cooling tower cell shall be sized for 50% of the building condenser water load. The basis of design for the cooling tower is the Evapco ESWA. 4) Two (2) end suction variable speed primary condenser water pumps shall circulate condenser water through the building for service to the water source heat pumps with all condenser coil control valves being 2-way for variable flow pumping. Each pump shall be sized for 50% of the building condenser water load. 5) The water source condenser system shall be modeled with a 10°F temperature difference and operate between 60°F and 85°F. b. Fan Coil Units 1) The water source heat pump units shall provide 100% recirculated air to meet the space sensible heating and cooling requirements. The WSHP shall be a packaged factory unit with a refrigerant-to- water coaxial heat exchanger, direct expansion refrigerant cooling/heating coil and ECM motor. The basis of design for the fan coil units is Trane Axiom model EXV. c. Outdoor Air Units 1) The dedicated outdoor air handling units shall provide 100% OA outdoor air to meet the nominal ventilating criteria, provide make- up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling unit shall be a custom unit with a refrigerant-to-water coaxial heat exchanger, direct expansion refrigerant cooling coil, heat pump

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heating coil, total energy enthalpy plate and frame heat exchanger and a sensible plate and frame heat exchanger. The basis of design for the outdoor air units is Annexair. 5. System 5: Variable Refrigerant Flow Fan Coil Units a. The system shall be comprised of a variable refrigerant flow, heat pump heat recovery air conditioning system, consisting of simultaneous cooling and heating split system heat pumps with R410A refrigerant and dedicated 100% outdoor air units to provide code required ventilation air. b. The variable refrigerant flow system shall consist of indoor concealed ducted fan coil units and outdoor air cooled condensing units. Each indoor unit or group of indoor units shall be capable of operating in any mode (cooling or heating) independently of other indoor units or groups. System shall be capable of changing mode (cooling to heating, heating to cooling) with no interruption to system operation. Each indoor unit or group of indoor units shall be independently controlled. Condensing unit shall be located outdoors at grade or on the roof. Basis of design is Mitsubishi City- Multi R2 Series. c. Fan Coil Units 1) The fan coil units shall provide 100% recirculated air to meet the space sensible heating and cooling requirements. The fan coil unit shall be a packaged factory unit with a direct expansion refrigerant coil and ECM motor. The basis of design for the fan coil units is Mitsubishi model PVFY. d. Outdoor Air Units 1) The dedicated outdoor air handling units shall provide 100% OA outdoor air to meet the nominal ventilating criteria, provide make- up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling unit shall be a custom air cooled direct expansion type unit with direct expansion refrigerant cooling coil, hot gas bypass re-heat coil, electric heating coil, total energy enthalpy plate and frame heat exchanger and a sensible plate and frame heat exchanger. The basis of design for the outdoor air units is Annexair. e. System Limitations 1) The proposed building architecture consists of a single story building with a pitched roof and a mechanical platform located in the interstitial space. The condensing units for the VRF system and dedicated outdoor air units are air cooled and therefore required to be located outdoors on grade. The VRF condensing units must be located close to the fan coil units they serve and therefore must be located throughout the site instead of a central mechanical yard. The dedicated outdoor air handling units must be located throughout the site in order to provide proper zone control and

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minimize duct size and length of duct run. Due to the system requirements of the air cooled equipment and the preferred building architecture it was decided that a VRF system was not a viable option and was therefore not modeled.

B. It is the preference of BCSD to self-perform the maintenance for all of the school districts HVAC systems. Like many school districts, maintenance funds and personnel are limited and because of this ease of maintenance for the HVAC system is extremely important. BCSD facilities personnel evaluated each of the proposed HVAC systems and offered the following observations in regards to system maintenance: 1. The school district has several 4 pipe and 2 pipe fan coil systems with in the school district. The dedicated outdoor air units, boilers and pumps are essentially the same for either the four pipe or two pipe system so the maintenance and repair of these components would be equivalent when using either system. Over the years, the maintenance department has noted that for a WSHP system rarely is there a requirement for heat. Recently one high school with a population of 1770 students went an entire winter without using a boiler while it was down several months for repair. 2. The maintenance and repair of the fan coil units and the water source heat pumps units are very similar. The maintenance department closely reviews all equipment and manufactures prior to installation in the new schools. Equipment that has a good history of quality performance, ease of maintenance and availability of reasonably priced training are selected. Equipment selections are not based on first costs alone. The maintenance staff works closely with the engineers to ensure that isolation valves, disconnects and controls are placed in such a manner that equipment can be easily maintained and filters can be replaced. Sufficient space is allocated in front of access panels so that motors, coils and pumps can be easily removed and maintained or replaced. In the last few years the district has standardized buildings so that the locations of the fan coil or WSHP units have sufficient accessibility. Either the units are located in a mechanical closet between two classrooms off the corridor or in interstitial spaces that have a mechanical platform with stair access. This allows equipment to be maintained and repaired while classes are in session. 3. System 1, 2, and 3 are all four pipe systems using air cooled chillers which require more training and experience to work on. Often the manufacturer is required to help trouble shoot any chiller problems which is an additional premium cost to the maintenance department. The four pipe systems also have double the piping, valves and pumps to maintain and repair. Twice as many components also means there are twice as many potential sources for leaks when compared to the 2 pipe Water Source Heat Pump system. 4. There is only one ice storage system within the school district and therefore only a few maintenance staff has experience with maintaining this system type. With the initial startup of the ice storage system there were problems with losing the glycol solution which is an additional loop to the four pipe system needing

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maintenance and repairs. Care must be taken to ensure glycol does not leak into the storm drain system and a tank of glycol solution must be readily available for any repairs or leaks. To a certain extent, the ice storage system works well with the controls in place and there have not been many issues in the first year of maintaining this system. 5. The WSHP systems use cooling towers for cooling. There are several cooling towers with in the school district. The cooling towers are easy to work on and operate. Some towers use well water and others use domestic water for make-up water. The maintenance department has found over the years that the chemicals needed for a well system can be very costly and labor intensive to regulate and maintain. Keeping the water chemistry correct is an essential health concern as well as an essential maintenance requirement in order to ensure that the pipes, pumps and equipment do not corrode. Recently, a cooling tower was added to an existing High School and the district was able to use domestic water service with an irrigation water meter for the make-up water. Having an irrigation water meter has eliminated the cost for sewer on the water usage for the tower which is a large savings to the school district. 6. Currently there are no VRF systems within school district. Maintenance personnel are familiar with direct expansion (DX) refrigerant systems since there are many DX systems throughout the existing schools and there are some similarities in the maintenance of these two systems. There is concern about having leaks with the VRF system and working on that system since it would be more complex and costly than water based system. Additionally multiple fan coil units are controlled by one air cooled compressor so when repairs are needed multiple classrooms could go down. Most schools can easily accommodate moving one classroom if a HVAC unit goes down but when several classrooms are involved, schools do not have that flexibility. Humidity control is also of great concern for this system especially in the summer when we put the HVAC systems on higher temperatures to reduce energy costs. During the summer, the maintenance department works closely with the school custodial staff when stripping, waxing and carpet cleaning occurs. When there is no dehumidification, mold and mildew quickly grows in areas which have been recently mopped or carpets cleaned since the setback temperatures are higher. The maintenance staff always has to be vigilant during the summer months when most of the classrooms are not occupied to ensure no humidity problems occur. In some isolated incidents in the past, some HVAC units where not operating correctly and the humidity quickly increased and cause growth of mold and mildew. The district had to quickly address remediation where mold and mildew started growing so that the opening of school was not delayed. When this occurs it is a very costly event to the school district since most time it involves a large amount of overtime work. 7. In summary, the maintenance department believes working on a 2-pipe WSHP system is has the greatest ease of maintenance and the least amount of parts and the least amount of risk for leaks. Most HVAC technicians are initially trained on components of the fan coil units and so each person in the department can

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respond to a trouble call. For the comfort of the classrooms WSHP system has much more flexibility than any other system in that one classroom can be in heating mode while another can be in cooling mode at the same time. Based on the location of the classrooms (north or south side) and the amount of windows there seems to be variations (heat vs. cool mode) for several classrooms throughout a large school.

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DIVISION 3 - SYSTEMS ANALYSIS

3.1 GENERAL

A. The HVAC systems were modeled using eQUEST version 3.64 and standard industry modeling protocols. In some instances the modeling software was unable to explicitly model the proposed design energy efficiency measures. In cases were the proposed design energy efficiency measures could not be modeled the measures were eliminated from all of the modeling scenarios as noted below.

3.2 WEATHER

A. Location 1. The project was modeled to be located at the site of the New Nexton Elementary School which is located in Summerville, South Carolina which is in ASHRAE Zone 3a.

B. Design conditions 1. The equipment design capacity was sized on the ASHRAE Fundamentals cooling design values based on 1% annual cumulative frequency of occurrence and the heating, humidification and wind design values are based on 99% annual cumulative frequency of occurrence for Charleston, South Carolina.

C. Yearly Modeled Conditions 1. The weather file used to simulate the 8760 annual hours was in the TMY2 format for Charleston, South Carolina.

3.3 ENVELOPE

A. The exterior walls have been modeled according to the architectural construction which can be seen in the figure below. The exterior wall contains three (3) inches of continuous insulation which has an R-value of 15. The total wall assembly has an R-value of 20.2 which can be seen in the table below.

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Material Thickness Conductivity Material (ft) (Btu/h-ft-F) R-value Face Brick 0.33 0.77 0.43 Air Gap 0.167 - 0.89 Board Insulation 0.25 0.0167 15.0 CMU 0.667 0.2083 3.2 Inside Air Film - - 0.68

Total R -Value 20.2

B. The roof has been modeled according to the architectural construction which can be seen in the figure below. The roof contains six (6) inches of continuous insulation which has an R-value of 30. The total roof assembly has an R-value of 30.62 which can be seen in the table below.

Material Thickness Conductivity Material (ft) (Btu/h-ft-F) R-value Metal Roof 0.005 26.00 0.0002 Board Insulation 0.5 0.0167 30.0 Steel Deck 0.005 26.00 0.0002 Air Film - - 0.62

Total R -Value 30.62

C. The floor has been modeled according to the architectural construction which can be seen in the figure below. The total floor assembly has an R-value of 13.9 which can be seen in the table below.

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Material Thickness Conductivity Material (ft) (Btu/h-ft-F) R-value Air Film - - 0.68 Vinyl Tile - - 0.05 Concrete Slab 0.33 0.2 1.65 Earth 2.88 0.25 11.52

Total R -Value 13.9

D. The windows and doors have been modeled according to the architectural construction which can be seen in the table below. Glass doors are modeled with the same glazing properties as the windows.

Material VT Conductivity SHGC (Btu/h-ft-F) Windows 0.64 0.29 0.28

Doors (Opaque) - 0.82 -

3.4 SCHEDULES

A. Year Schedule 1. The HVAC systems were modeled for 8760 hours starting on January 1st 2013 and ending on December 31 st 2013. The BCSD school calendar was used to approximate the yearly occupied/unoccupied schedule. 2. The school was assumed to operate Monday through Friday only. The occupied/unoccupied schedules contained in the model can be seen in the table below.

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Season Week Days Start Date End Date School in Session Monday -Friday 01/03/2013 03/29/2013 School in Session Monday -Friday 04/08/2013 05/31/2013 School in Session Monday -Friday 08/19/2013 12/20/2013

Summer Hours Tuesday -Thursday 06/17/2013 08/16/2013

Breaks/Holidays Monday -Sunday All other Weekdays and Holidays

B. Day Schedule 1. The BCSD school schedule was used to approximate the daily occupied/ unoccupied schedule. The daily occupied/unoccupied schedules contained in the model can be seen in the table below.

Season Occupied/ Opens At Closes At Unoccupied School in Session Occupied 7:00 AM 4:00 PM

Summer Hours Occupied 7:00 AM 5:00 PM

Breaks/Holidays Unoccupied Closed Closed

3.5 INTERIOR DESIGN CONDITIONS

A. Temperature and Humidity Set Points 1. The indoor design temperature conditions were modeled to be 75°F in the cooling mode and 70°F in the heating mode with a range of plus/minus 2°F. 2. The indoor design humidity conditions in the cooling mode were modeled to be 50% RH. A minimum humidity value was not modeled for the heating mode. 3. The fan coil units were modeled to satisfy the temperature setpoints while the dedicated outdoor air units were modeled to provide neutral supply air and satisfy the building humidity setpoint.

B. Internal Heat Gains 1. Occupants a. Occupants were modeled with a sensible heat gain of 245 BTU and a latent heat gain of 155 BTU. 2. Equipment a. The equipment loads were modeled with the following power density and 100% sensible heat gain to the space. 1) Classrooms: 1.5 W/SF

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2) Offices: 1.5 W/SF 3) Computer Labs: 10 W/SF 4) Media Center: 1.5 W/SF 5) Main Electrical and IT Rooms: 5 W/SF 6) All Other Spaces: no equipment load 3. Lighting a. The lighting power density for all spaces was modeled based upon the ASHRAE 90.1 Whole Building method which specifies a maximum lighting power density for K-12 schools of 1.2 watts per square foot. b. The lighting schedule was modeled identical to the occupancy schedule. c. Exterior connected lighting loads were not modeled.

3.6 UTILITY RATES

A. Electricity 1. The electrical rate is modeled upon Berkeley Electric Co-op Rate 30 utility structure. Rate 30 currently has a Monthly Adjustment Factor (MAF) credit of $0.025 per kWh which has been included in the rates below. The demand charge was modeled using a 30 minute demand window. The modeled utility structure can be seen in the table below.

Type of Cost Energy Unit of Charge Block Charge Service Charge $187.5 Monthly - Demand Charge $6.25 Per/kW kW

Energy Charge 7.4 ¢ First 250 kWh/kW kWh 6.4 ¢ Next 250 kWh/kW kWh 5.4 ¢ >500 kWh/kW kWh

B. Natural Gas 1. The natural gas rate is modeled upon SCE&G Rate 33 utility structure. The modeled utility structure can be seen in the table below.

Type of Cost Energy Unit of Charge Block Charge Service Charge $28.65 Monthly - Energy Charge $0.99067 Per/Therm Therm

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3.7 HVAC SYSTEMS

A. General 1. The HVAC systems are modeled to energize one (1) hour before the school is occupied and deenergize one (1) hour after the school is unoccupied. a. The fan coil units are modeled so that they cannot be energized in the unoccupied mode. b. The dedicated outdoor are units are modeled so that they can be energized with 100% recirculated air (no outdoor air) in the unoccupied mode in order to satisfy the unoccupied building temperature setpoints. 2. The hydronic loop(s) and associated equipment are modeled to operate whenever there is a demand for heating or cooling from a fan coil or dedicated outdoor air unit.

B. System 1: Chilled and Heating Water Fan Coil Units (with Ice Storage) 1. Building Heating Water System a. A variable speed, variable flow primary heating water pumping system was modeled for the distribution of heating water. The heating water system was modeled with a 30°F temperature difference (160°F to 130°F) and was scheduled to operate on an adjustable proportional reset schedule based on outdoor temperature to maximize energy efficiency. 1) Two (2) 2000 CFH input natural gas fired, 96% efficient, condensing heating water boilers were modeled to generate 160°F supply heating water. 2) Two (2) 7.5 HP variable volume primary heating water pumps were modeled with a capacity of 180 GPM at 90 feet to circulate the heating water through the gas-fired heating water boilers and building heating water coils. 2. Building Chilled Water System a. A variable speed, variable flow primary chilled water system was modeled to provide chilled water for the building fan coil units and dedicated outdoor air units chilled water coils. A constant volume primary glycol water system with ice storage was modeled for the distribution of glycol water for the chillers and ice storage system. 1) Two (2) 155 ton, 2.9 COP electric air-cooled centrifugal chillers were modeled to generate chilled water at a temperature dependent on the operating mode. In “ice build” the chillers were modeled to run at 100% capacity until a return water temperature of 21 °F is sensed. In all other modes the combination of chiller operation and ice melt shall produce 40°F leaving water temperature. a) In “ice build” mode the chillers were modeled with the same parameters as “ice melt” mode but with a

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reduced chiller capacity of 108 tons each. 2) Two (2) 20 HP constant speed primary glycol water pumps were modeled with a capacity of 465 GPM at 90 feet to circulate glycol water through the chillers, ice storage tanks and plate heat exchanger. 3) Two (2) 20 HP variable speed primary chilled water pumps were modeled at 430 GPM at 110 feet to circulate chilled water through the building chilled water coils and plate heat exchanger. 4) The ice storage system was modeled with a capacity of 408 ton hours. 5) The chilled water system was modeled with a 14°F temperature difference (54°F to 40°F). 6) The glycol water system was modeled with a 6°F temperature difference (27°F to 21°F). 3. Fan Coil Units a. Constant volume blower coil units were modeled to provide 100% recirculated air to meet the space sensible heating and cooling requirements. The fan coil unit modeled capacities can be seen in the table below.

Nominal Capacity Airflow External Static Chilled/Heating (tons) (CFM) Pressure Water Delta T 1.8 600 0.35 14 °F 2.0 800 0.35 14 °F 3.0 1200 0.50 14 °F 4.0 1600 0.50 14 °F 5.0 2000 0.50 14 °F 4. Outdoor Air Units a. Constant volume dedicated outdoor air handling units were modeled to provide 100% outdoor air to meet the nominal ventilating criteria, provide make-up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling units were modeled with a heating water coil, chilled water coil and total energy enthalpy plate exchanger which was modeled to capture waste energy from the exhaust airstream. The dedicated outdoor air unit modeled capacities can be seen in the table below.

Supply Airflow Exhaust Airflow External Static Chilled/Heating (CFM) (CFM) Pressure Water Delta T 30,000 27,750 1.5 14 °F 3,250 2,500 1.5 14 °F 8,000 NA 1.5 14 °F

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C. System 2: Chilled and Heating Water Fan Coil Units (without Ice Storage) 1. Building Heating Water System a. A variable speed, variable flow primary heating water pumping system was modeled for the distribution of heating water. The heating water system was modeled with a 30°F temperature difference (160°F to 130°F) and was scheduled to operate on an adjustable proportional reset schedule based on outdoor temperature to maximize energy efficiency. 1) Two (2) 2000 CFH input natural gas fired, 96% efficient, condensing heating water boilers were modeled to generate 160°F supply heating water. 2) Two (2) 7.5 HP variable volume primary heating water pumps were modeled with a capacity of 180 GPM at 90 feet to circulate the heating water through the gas-fired heating water boilers and the building heating water coils. 2. Building Chilled Water System a. A variable speed, variable flow primary chilled water system was modeled to provide chilled water for the building fan coil units and dedicated outdoor air units chilled water coils. 1) Two (2) 250 ton, 2.88 COP electric air-cooled centrifugal chillers were modeled to generate chilled water at 40°F supply. 2) Two (2) 20 HP variable speed primary chilled water pumps were modeled at 430 GPM at 110 feet to circulate chilled water through the chiller and building chilled water coils. 3) The chilled water system was modeled with a 14°F temperature difference (54°F to 40°F). 3. Fan Coil Units a. Constant volume blower coil units were modeled to provide 100% recirculated air to meet the space sensible heating and cooling requirements. The fan coil unit modeled capacities can be seen in the table below.

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a. Constant volume dedicated outdoor air handling units were modeled to provide 100% outdoor air to meet the nominal ventilating criteria, provide make-up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling units were modeled with a heating water coil, chilled water coil and total energy enthalpy plate exchanger which was modeled to capture waste energy from the exhaust airstream. The dedicated outdoor air unit modeled capacities can be seen in the table below.

Supply Airflow Exhaust Airflow External Static Chilled/Heating (CFM) (CFM) Pressure Water Delta T 30,000 27,750 1.5 14 °F 3,250 2,500 1.5 14 °F 8,000 NA 1.5 14 °F

D. System 3: Chilled and Heating Water Fan Coil Units (Turbocor Compressors) 1. System 3 was modeled identical to System 2 except for the chillers. 1) Two (2) 250 ton, 2.86 COP electric air-cooled high efficiency magnetically levitated bearing centrifugal chillers (Turbocor Compressor) were modeled to generate chilled water at 40°F supply.

E. System 4: Water Source Heat Pump Units 1. Building Water Loop System a. A variable speed, variable flow primary water loop pumping system was modeled for the distribution of loop water. The loop water system was modeled with a 10°F temperature difference and was modeled to operate between 65°F and 85°F to maximize energy efficiency. 1) Two (2) 1350 CFH input natural gas fired, 96% efficient, condensing heating water boilers were modeled to supply heating water to the water loop. 2) Two (2) 20 HP variable speed primary condenser water pumps were modeled at 430 GPM at 110 feet to circulate chilled water through the boiler, fluid cooler and building condenser water coils. 2. Fan Coil Units a. Constant volume blower coil units were modeled with an EER of 16.5 in cooling mode and a COP of 3.5 in heating mode to provide 100% recirculated air to meet the space sensible heating and cooling requirements. The fan coil unit modeled w capacities can be seen in the table below.

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Nominal Capacity Airflow External Static Loop (tons) (CFM) Pressure Water Delta T 1.8 600 0.35 10 °F 2.0 800 0.35 10 °F 3.0 1200 0.50 10 °F 4.0 1600 0.50 10 °F 5.0 2000 0.50 10 °F 3. Outdoor Air Units a. Constant volume dedicated outdoor air handling units were modeled with a EER of 16.5 in cooling mode and a COP of 3.5 in heating mode to provide 100% outdoor air to meet the nominal ventilating criteria, provide make-up air for building exhaust and to maintain a positive building pressure to offset system exhaust. The outdoor air handling unit was modeled with a heating water coil, chilled water coil and total energy enthalpy plate exchanger which was modeled to capture waste energy from the exhaust airstream. The dedicated outdoor air unit modeled capacities can be seen in the table below.

Supply Airflow Exhaust Airflow External Static Condenser (CFM) (CFM) Pressure Water Delta T 30,000 27,750 1.5 10 °F 3,250 2,500 1.5 10 °F 8,000 NA 1.5 10 °F

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DIVISION 4 - LIFE CYCLE COST ANALYSIS

4.1 ANALYSIS

A. A life cycle cost analysis was completed in order to determine which system type has the lowest cost over a twenty year period. The components used to determine the life cycle cost are as follows: 1. The capital project cost (first costs) was calculated using the construction cost, which can be seen as Appendix item 5.6, and soft costs based upon 25% of the construction cost. 2. The annual costs were calculated using the annual energy usage and maintenance cost. Electrical costs were calculated based upon a 4% escalation rate. Natural gas and maintenance costs were calculated based upon a 2% escalation rate. The escalation rates were used in conjunction with a discount factor of 5% in order to calculate the present value of the annual costs. 3. System 4 – water source heat pump has an effective life of 15 years compared to 20 years for the other three (3) systems. In order to accurately compare the systems it was assumed that 33% of System 4 would have to be replaced during year 15.

B. The life cycle cost analysis calculations summery can be seen as Appendix item 5.7

4.2 RESULTS

A. The total present value over a 20 year period for of each of the four (4) systems can be seen in the table below.

System Capital Cost First Year Life Cycle Cost ($) Annual Cost ($) ($) System 1: FCU w/Ice Storage $2,523,940 $165,359 $5,423,740 System 2: FCU w/o Ice Storage $2,371,356 $153,380 $5,058,456 System 3: FCU w/Turbocor Chiller $2,490,496 $144,504 $5,018,896 System 4: Water Source Heat Pump $1,748,630 $126,772 $4,362,030

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DIVISION 5 - APPENDICES

5.1 DEDICATED OUTDOOR AIR SYSTEM CONFIGURATION

5.2 BUILDING ARCHITECTURE

5.3 EQUEST INPUTS

5.4 UTILITY RATES

5.5 OUTPUT REPORTS

5.6 FIRST COST CALCULATIONS

5.7 LIFE CYCLE COST ANALYSIS CALCULATIONS

5.8 RMF MEMO FOR CANE BAY ELEMENTARY SCHOOL HVAC SYSTEM CONFIGURATION

5.9 FIRM BACKGROUND

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5–

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PART 1 – TEMPERATURE CONTROL SEQUENCES

A. A full communications interface and complete interoperability with the new Siemens DDC automatic temperature control system shall be provided to perform the functions herein described or indicated in the contract documents. All temperature, humidity, carbon dioxide, pressure and time set points shall be fully adjustable from the BAS. PART 2 – MASTER HEATING AND COOLING CONTROL

A. The BAS shall normally control the system heating and cooling modes as selected in accordance with outdoor air temperature through building global outdoor air sensor. On a rise in outdoor air temperature to fifty (50) degrees Fahrenheit (adjustable) and above, systems shall operate in the cooling mode. On a fall in outdoor air temperature below fifty (50) degrees Fahrenheit systems shall operate in the heating mode.

B. Control point adjustment for “heating” and “cooling” changeover temperature shall be by the BAS. PART 3 – AIR HANDLING CONTROL

A. System control 1. Supply fan and return fan shall be manually indexed to the automatic mode at their respective variable frequency drives. 2. The air handling unit shall be energized via remote signal from the BAS. The BAS shall determine and operate the unit on an optimal occupied and unoccupied schedule with a 365 day/24 hour graphic interface schedule program. 3. When the unit is deenergized through the BAS, all controls shall return to their normal position ready for restarting. The supply and return fan shall deenergize and, after an adjustable interval, outdoor air and exhaust air dampers shall close. Water source heat pump refrigerant circuit shall deenergize. 4. Supply fan and return fan shall not operate until their respective fan isolation dampers have been proven open. Upon a failure of any of the dampers to open, an alarm shall be annunciated at the BAS. 5. When the supply fan is soft started to minimum speed through the BAS, the return fan shall soft start to minimum speed and run continuously. Upon a failure of dampers to open, the air handling unit shall be deenergized and an alarm shall be annunciated at the BAS. 6. The supply fan speed shall be modulated via the VFD to maintain constant system supply airflow as sensed by its airflow monitoring device. 7. The supply fan shall be provided with a high limit control function which shall limit the cfm of the fan to 115% of its scheduled quantity. The high limit control function shall override space temperature set point control, and shall deenergize the supply fans if the cfm exceeds the high cfm limit. 8. Return air damper shall be closed during the occupied schedule and open during

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

the unoccupied schedule. Failure of the return air damper to open during the unoccupied schedule shall alarm the BAS. 9. A failure of either supply or return fan as sensed by their respective current transducers shall be alarmed to the BAS. Upon sensing failure, the BAS shall indicate alarm, disable the fan and return all controls to their normal position. 10. Static pressure switch shall annunciate an alarm at the BAS and deenergize the supply fan when the high static pressure set point is reached (4” w.g. – adjustable). 11. Outdoor air and exhaust air isolation dampers shall fail closed. Unit shall deenergize if any of the dampers that are required to be proven open for normal operation have failed closed.

B. Heating mode 1. Water source heat pump refrigerant circuit shall be energized during the heating mode. 2. The BAS shall energize and modulate the water source heat pump system to maintain the occupied leaving air temperature setpoint of 72°f (adj). 3. Occupied mode: the supply and return fan shall be running; exhaust, outdoor air, and supply air dampers shall be open. The BAS shall energize and modulate the heat pump heating coil to maintain the occupied leaving air temperature setpoint as seen by the supply air temperature sensor. Upon a rise in supply air temperature above setpoint, the reverse shall occur. 4. Unoccupied mode: the BAS shall determine the unoccupied mode based on a 365 day/24 hour graphic interface scheduler program. The air handling unit shall be deenergized when the unoccupied mode is initiated. In the unoccupied mode the unit shall energize when the space temperature drops below the unoccupied temperature setpoint of 50°f (adj), and continue to operate until zone temperature reaches 55°f (5°f deadband – adj).

C. Cooling mode 1. Water source heat pump refrigerant circuit shall be energized during the cooling mode. 2. The BAS shall energize and modulate the water source heat pump system to maintain the occupied leaving air temperature according to the leaving air temperature graph below. 3. Occupied mode: supply and return fan shall be running; exhaust damper shall be open; outdoor damper shall be open to its minimum balanced position. The BAS shall energize and control the dx refrigerant coil to maintain the occupied supply air temperature setpoint as seen by the supply air temperature sensor. Upon a drop in discharge air temperature below setpoint, the reverse shall occur. Refer to leaving air temperature schedule. Return air humidity sensor shall override

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

return air temperature sensor when the return air relative humidity reaches sixty (60) percent (adj). Cooling coil shall be modulated to gradually lower the supply air temperature. When the return air relative humidity, as seen by the return air humidity sensor, drops below fifty-five (55) percent, control of the cooling coil shall be returned to discharge air temperature control.

4. Unoccupied mode: the BAS shall determine the unoccupied mode based on a 365 day/24 hour graphic interface scheduler program. The air handling unit shall be deenergized when the unoccupied mode is initiated. While in the unoccupied mode the unit shall energize when the space temperature rises above the unoccupied temperature setpoint of 85°f and/or dewpoint setpoint of 65°f (adj), and continue to operate until zone temperature reaches 85°f and/or dewpoint setpoint of 65°f (5°f deadband – adj).

D. Smoke control 1. Any air distribution (HVAC) smoke detector shall, on the detection of products of combustion, shut down the respective supply and return fans serving that distribution system and close all system dampers in accordance with nfpa-90a. All HVAC smoke detectors shall be connected to the fire alarm system, as a supervisory alarm only, in accordance with the requirements of nfpa-71 – national fire alarm code. 2. Upon an initiation signal from the fire alarm system, the air handling unit and all associated system return fans shall deenergize and an alarm shall be annunciated at the BAS.

E. Alarms and failure modes 1. A failure of the supply fan or the return fan, as sensed by their respective current transducers, shall be alarmed to the BAS. Upon sensing failure, the BAS shall indicate alarm, disable all fans and return all controls to their normal position. 2. Two-way loop water valve shall open to the minimum position when the outdoor air temperature, as sensed by the global outdoor air temperature sensor, drops below thirty-five (35) degrees Fahrenheit.

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

F. Programs 1. Optimal total energy plate and frame heat exchanger program shall be incorporated which shall minimize the overall heating energy, cooling energy and fan power consumption while maintaining design temperature and humidity conditions. 2. Optimal plate and frame heat exchanger program shall be incorporated which shall reduce cooling energy, fan energy and provide free reheat while maintaining design temperature and humidity conditions.

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

Revit Building Architecture

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RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0

BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

5.–

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

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RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0

BERKELEY ELECTRIC COOPERATIVE, INC. Moncks Corner, South Carolina

SCHOOL SERVICE RATE SCHEDULE "SCH"

RATE 30 AVAILABILITY:

Available in all territory served by the Cooperative near lines of adequate capacity subject to the Cooperative's Service Rules and Regulations.

APPLICABILITY:

For electric service to schools of one standard secondary voltage required on consumer's premises, delivered at one point and metered at and compensated to that voltage and where required transformer capacity exceeds 100 kVA.

TYPE OF SERVICE:

Multi-phase service, 60 hertz, at the following standard voltages: 120/240, 120/208, 277/480, 240/480 or other voltages as might be mutually agreeable.

RATE (MONTHLY):

Service Charge @ $187.50 per month

Demand Charge:

All kW @ $ 6.25 per kW of billing demand

Energy Charge:

First 250 kWh per kW of billing demand @ 9.9¢ per kWh Next 250 kWh per kW of billing demand @ 8.9¢ per kWh Over 500 kWh per kW of billing demand @ 7.9¢ per kWh

MINIMUM CHARGE (MONTHLY):

The greater of: A. $1.00 per kVa of installed transformer capacity. B. Contract minimum. C. The Demand Charge. SOUTH CAROLINA ELECTRIC & GAS COMPANY GAS RATE 33 MEDIUM GENERAL SERVICE

AVAILABILITY

Available only to those customers using the Company's service for firm general commercial, industrial, agriculture, religious or charitable purposes and for residential where more than one dwelling unit is supplied through one meter. Also, this rate schedule is only available where there is an average usage of at least 130 therms during the billing months of June, July and August. The average usage is derived by combining the therm usage for each of the billing months previously listed and dividing by three. It is not available for resale.

RATE PER MONTH

Basic Facilities Charge: $28.65

Plus Commodity Charge: All Therms @ $ 0.99067 per therm

WEATHER NORMALIZATION ADJUSTMENT

An adjustment to the commodity charges for the billing months of November-April above will be made in accordance with the Weather Normalization Adjustment.

DEKATHERM BILLING

Customers that have installed chart metering facilities may be billed on a per Dekatherm basis (1 dekatherm = 10 therms). The amount per dekatherm will be determined by multiplying the above by 10.

MINIMUM CHARGE

The monthly minimum charge shall be the basic facilities charge as stated above.

UNMETERED GAS LIGHTING PROVISION

Gas used for lighting will be determined based on BTU ratings of fixtures installed and will be billed the commodity charges listed above.

SEASONAL BLOCK CHARGE

A charge will apply for customers who disconnect service and subsequently request reconnection of service at the same premise within a 12 month period. This is commonly referred to as seasonal block. The charge will be based on the number of months the customer is disconnected times the basic facilities charge as stated above. In determining the months of disconnection, any number of days disconnected within a month constitutes a whole month of disconnection. If reconnection is requested to be performed after normal business hours, an additional charge of $20.00 will be added to the charges as calculated above.

ADJUSTMENT FOR RECOVERY OF GAS COSTS

The commodity charges above include gas costs of $0.54287 per therm and are subject to adjustment by order of the Public Service Commission of South Carolina.

SALES AND FRANCHISE TAX

To the above will be added any applicable sales tax, franchise fee or business license tax which may be assessed by any state or local governmental body.

PAYMENT TERMS

All bills are net and payable when rendered.

TERM OF CONTRACT

Contracts shall run continuously from time service is commenced at each location until service to customer is permanently disconnected. A separate contract shall cover each meter at each location. No contract shall be written for less than twelve (12) months.

GENERAL TERMS AND CONDITIONS

The Company's General Terms and Conditions are incorporated by reference and a part of this rate schedule.

Effective For Bills Rendered On and After the 1st Billing Cycle of May 2013 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

5.5- ors

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BCSD Nexton S1 FCU w/Ice DOE-2.2-47h2 7/10/2013 11:10:06 BDL RUN 4

REPORT- BEPS Building Energy Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY MBTU 0.0 0.0 0.0 5.7 1380.5 0.0 355.9 398.5 0.0 0.0 0.0 0.0 2142.2

EM2 ELECTRICITY MBTU 1134.3 0.0 1364.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2499.0

FM1 NATURAL-GAS MBTU 0.0 0.0 0.0 963.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 963.2 ======

MBTU 1134.3 0.0 1364.7 968.9 1380.5 0.0 355.9 398.5 0.0 0.0 0.0 0.0 5604.5

TOTAL SITE ENERGY 5604.45 MBTU 57.0 KBTU/SQFT-YR GROSS-AREA 57.0 KBTU/SQFT-YR NET-AREA TOTAL SOURCE ENERGY 14886.87 MBTU 151.5 KBTU/SQFT-YR GROSS-AREA 151.5 KBTU/SQFT-YR NET-AREA

PERCENT OF HOURS ANY SYSTEM ZONE OUTSIDE OF THROTTLING RANGE = 1.81 PERCENT OF HOURS ANY PLANT LOAD NOT SATISFIED = 0.00 HOURS ANY ZONE ABOVE COOLING THROTTLING RANGE = 22 HOURS ANY ZONE BELOW HEATING THROTTLING RANGE = 145

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES.

NOTE: RESIDUAL ENERGY IN THERMAL STORAGE DEVICES IS INCLUDED IN THE TOTALS, BUT NOT IN THE END-USE CATEGORIES. BCSD Nexton S1 FCU w/Ice DOE-2.2-47h2 7/10/2013 11:10:06 BDL RUN 4

REPORT- BEPU Building Utility Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY KWH 0. 0. 0. 1671. 404477. 0. 104288. 116755. 0. 0. 0. 0. 627667.

EM2 ELECTRICITY KWH 332337. 0. 399867. 0. 0. 0. 0. 0. 0. 0. 0. 0. 732205.

FM1 NATURAL-GAS THERM 0. 0. 0. 9632. 0. 0. 0. 0. 0. 0. 0. 0. 9632.

TOTAL ELECTRICITY 1359872. KWH 13.836 KWH /SQFT-YR GROSS-AREA 13.836 KWH /SQFT-YR NET-AREA TOTAL NATURAL-GAS 9632. THERM 0.098 THERM /SQFT-YR GROSS-AREA 0.098 THERM /SQFT-YR NET-AREA

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES.

NOTE: RESIDUAL ENERGY IN THERMAL STORAGE DEVICES IS INCLUDED IN THE TOTALS, BUT NOT IN THE END-USE CATEGORIES. BCSD Nexton S1 FCU w/Ice DOE-2.2-47h2 7/10/2013 11:10:06 BDL RUN 4

REPORT- ES-D Energy Cost Summary WEATHER FILE- Charleston SC TMY2 ------

METERED TOTAL VIRTUAL ENERGY CHARGE RATE RATE USED UTILITY-RATE RESOURCE METERS UNITS/YR ($) ($/UNIT) ALL YEAR? ------

BEC Rate 30 ELECTRICITY EM1 EM2 1359873. KWH 147566. 0.1085 YES

SCE&G Rate 33 NATURAL-GAS FM1 9632. THERM 9886. 1.0264 YES

======157452.

ENERGY COST/GROSS BLDG AREA: 1.60 ENERGY COST/NET BLDG AREA: 1.60 BCSD Nexton S1 FCU w/Ice DOE-2.2-47h2 7/10/2013 11:10:06 BDL RUN 4

REPORT- ES-E Summary of Utility-Rate: BEC Rate 30 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: ELECTRICITY DEMAND-INTERVAL 30 3413. BTU/KWH BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: EM1 EM2 POWER-FACTOR: 0.80 EXCESS-KVAR-FRAC: 0.75 EXCESS-KVAR-CHG: 0.0000

RATE-QUALIFICATIONS BLOCK-CHARGES DEMAND-RATCHETS MIN-MON-RATCHETS ------MIN-ENERGY: 0.0 Cust 1 Elec Energy Blk1 MAX-ENERGY: 0.0 Cust 1 Elec Demand Blk1 MIN-DEMAND: 0.0 MAX-DEMAND: 0.0 QUALIFY-RATE: ALL YEAR USE-MIN-QUAL: NO

METERED BILLING METERED BILLING ENERGY DEMAND ENERGY FIXED MINIMUM VIRTUAL TOTAL ENERGY ENERGY DEMAND DEMAND CHARGE CHARGE CST ADJ TAXES SURCHRG CHARGE CHARGE RATE CHARGE MONTH KWH KWH KW KW ($) ($) ($) ($) ($) ($) ($) ($/UNIT) ($) ------

JAN 98328 98328 446.7 446.7 7276 2792 0 0 0 188 0 0.1043 10256

FEB 95987 95987 509.7 509.7 7103 3185 0 0 0 188 0 0.1091 10476

MAR 113997 113997 556.4 556.4 8436 3477 0 0 0 188 0 0.1061 12101

APR 103933 103933 620.3 620.3 7691 3877 0 0 0 188 0 0.1131 11755

MAY 154567 154567 673.1 673.1 11438 4207 0 0 0 188 0 0.1024 15833

JUN 61803 61803 571.4 571.4 4573 3571 0 0 0 188 0 0.1348 8332

JUL 102192 102192 588.9 588.9 7562 3681 0 0 0 188 0 0.1119 11430

AUG 143503 143503 731.8 731.8 10619 4574 0 0 0 188 0 0.1072 15381

SEP 166594 166594 719.5 719.5 12328 4497 0 0 0 188 0 0.1021 17013

OCT 133362 133362 613.5 613.5 9869 3834 0 0 0 188 0 0.1042 13891

NOV 102208 102208 548.2 548.2 7563 3426 0 0 0 188 0 0.1094 11177

DEC 83398 83398 570.1 570.1 6171 3563 0 0 0 188 0 0.1190 9922 ======

TOTAL 1359873 1359873 731.8 100631 44685 0 0 0 2250 0.1085 147566 BCSD Nexton S1 FCU w/Ice DOE-2.2-47h2 7/10/2013 11:10:06 BDL RUN 4

REPORT- ES-E Summary of Utility-Rate: SCE&G Rate 33 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: NATURAL-GAS DEMAND-INTERVAL 60 100000. BTU/THERM BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: FM1

RATE-QUALIFICATIONS BLOCK-CHARGES DEMAND-RATCHETS MIN-MON-RATCHETS ------MIN-ENERGY: 0.0 Custom Gas Energy Blk1 MAX-ENERGY: 0.0 MIN-DEMAND: 0.0 MAX-DEMAND: 0.0 QUALIFY-RATE: ALL YEAR USE-MIN-QUAL: NO

METERED BILLING METERED BILLING ENERGY DEMAND ENERGY FIXED MINIMUM VIRTUAL TOTAL ENERGY ENERGY DEMAND DEMAND CHARGE CHARGE CST ADJ TAXES SURCHRG CHARGE CHARGE RATE CHARGE MONTH THERM THERM THERM/HR THERM/HR ($) ($) ($) ($) ($) ($) ($) ($/UNIT) ($) ------

JAN 674 674 14.9 14.9 667 0 0 0 0 29 0 1.0332 696

FEB 625 625 7.8 7.8 619 0 0 0 0 29 0 1.0365 648

MAR 662 662 7.1 7.1 656 0 0 0 0 29 0 1.0340 684

APR 726 726 7.3 7.3 719 0 0 0 0 29 0 1.0302 747

MAY 1142 1142 7.1 7.1 1132 0 0 0 0 29 0 1.0158 1160

JUN 476 476 7.4 7.4 472 0 0 0 0 29 0 1.0508 500

JUL 916 916 7.2 7.2 907 0 0 0 0 29 0 1.0219 936

AUG 1134 1134 7.1 7.1 1123 0 0 0 0 29 0 1.0159 1152

SEP 1251 1251 7.0 7.0 1240 0 0 0 0 29 0 1.0136 1268

OCT 871 871 7.2 7.2 863 0 0 0 0 29 0 1.0236 892

NOV 669 669 7.2 7.2 663 0 0 0 0 29 0 1.0335 691

DEC 487 487 7.0 7.0 482 0 0 0 0 29 0 1.0495 511 ======

TOTAL 9632 9632 14.9 9543 0 0 0 0 344 1.0264 9886 BCSD Nexton S2 FCU w/o Ice DOE-2.2-47h2 7/10/2013 11:07:00 BDL RUN 3

REPORT- BEPS Building Energy Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY MBTU 0.0 0.0 0.0 5.7 1275.9 0.0 21.7 398.9 0.0 0.0 0.0 0.0 1702.3

EM2 ELECTRICITY MBTU 1134.3 0.0 1364.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2499.0

FM1 NATURAL-GAS MBTU 0.0 0.0 0.0 963.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 963.0 ======

MBTU 1134.3 0.0 1364.7 968.7 1275.9 0.0 21.7 398.9 0.0 0.0 0.0 0.0 5164.2

TOTAL SITE ENERGY 5164.22 MBTU 52.5 KBTU/SQFT-YR GROSS-AREA 52.5 KBTU/SQFT-YR NET-AREA TOTAL SOURCE ENERGY 13566.77 MBTU 138.0 KBTU/SQFT-YR GROSS-AREA 138.0 KBTU/SQFT-YR NET-AREA

PERCENT OF HOURS ANY SYSTEM ZONE OUTSIDE OF THROTTLING RANGE = 1.80 PERCENT OF HOURS ANY PLANT LOAD NOT SATISFIED = 0.00 HOURS ANY ZONE ABOVE COOLING THROTTLING RANGE = 21 HOURS ANY ZONE BELOW HEATING THROTTLING RANGE = 145

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES. BCSD Nexton S2 FCU w/o Ice DOE-2.2-47h2 7/10/2013 11:07:00 BDL RUN 3

REPORT- BEPU Building Utility Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY KWH 0. 0. 0. 1670. 373846. 0. 6360. 116891. 0. 0. 0. 0. 498767.

EM2 ELECTRICITY KWH 332337. 0. 399867. 0. 0. 0. 0. 0. 0. 0. 0. 0. 732205.

FM1 NATURAL-GAS THERM 0. 0. 0. 9630. 0. 0. 0. 0. 0. 0. 0. 0. 9630.

TOTAL ELECTRICITY 1230972. KWH 12.524 KWH /SQFT-YR GROSS-AREA 12.524 KWH /SQFT-YR NET-AREA TOTAL NATURAL-GAS 9630. THERM 0.098 THERM /SQFT-YR GROSS-AREA 0.098 THERM /SQFT-YR NET-AREA

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES. BCSD Nexton S2 FCU w/o Ice DOE-2.2-47h2 7/10/2013 11:07:00 BDL RUN 3

REPORT- ES-D Energy Cost Summary WEATHER FILE- Charleston SC TMY2 ------

METERED TOTAL VIRTUAL ENERGY CHARGE RATE RATE USED UTILITY-RATE RESOURCE METERS UNITS/YR ($) ($/UNIT) ALL YEAR? ------

BEC Rate 30 ELECTRICITY EM1 EM2 1230971. KWH 136089. 0.1106 YES

SCE&G Rate 33 NATURAL-GAS FM1 9630. THERM 9883. 1.0264 YES

======145972.

ENERGY COST/GROSS BLDG AREA: 1.49 ENERGY COST/NET BLDG AREA: 1.49 BCSD Nexton S2 FCU w/o Ice DOE-2.2-47h2 7/10/2013 11:07:00 BDL RUN 3

REPORT- ES-E Summary of Utility-Rate: BEC Rate 30 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: ELECTRICITY DEMAND-INTERVAL 30 3413. BTU/KWH BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: EM1 EM2 POWER-FACTOR: 0.80 EXCESS-KVAR-FRAC: 0.75 EXCESS-KVAR-CHG: 0.0000

JAN 90703 90703 423.5 423.5 6712 2647 0 0 0 188 0 0.1052 9546

FEB 88463 88463 480.5 480.5 6546 3003 0 0 0 188 0 0.1101 9737

MAR 105031 105031 531.8 531.8 7772 3324 0 0 0 188 0 0.1074 11283

APR 94964 94964 595.5 595.5 7027 3722 0 0 0 188 0 0.1152 10937

MAY 141372 141372 658.7 658.7 10462 4117 0 0 0 188 0 0.1044 14766

JUN 51736 51736 544.2 544.2 3828 3401 0 0 0 188 0 0.1434 7417

JUL 89877 89877 543.3 543.3 6651 3395 0 0 0 188 0 0.1139 10234

AUG 127427 127427 698.3 698.3 9430 4365 0 0 0 188 0 0.1097 13982

SEP 149369 149369 694.4 694.4 11053 4340 0 0 0 188 0 0.1043 15581

OCT 122449 122449 592.0 592.0 9061 3700 0 0 0 188 0 0.1057 12949

NOV 93697 93697 528.6 528.6 6934 3304 0 0 0 188 0 0.1113 10425

DEC 75884 75884 548.8 548.8 5615 3430 0 0 0 188 0 0.1217 9233 ======

TOTAL 1230971 1230971 698.3 91092 42747 0 0 0 2250 0.1106 136089 BCSD Nexton S2 FCU w/o Ice DOE-2.2-47h2 7/10/2013 11:07:00 BDL RUN 3

REPORT- ES-E Summary of Utility-Rate: SCE&G Rate 33 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: NATURAL-GAS DEMAND-INTERVAL 60 100000. BTU/THERM BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: FM1

RATE-QUALIFICATIONS BLOCK-CHARGES DEMAND-RATCHETS MIN-MON-RATCHETS ------MIN-ENERGY: 0.0 Custom Gas Energy Blk1 MAX-ENERGY: 0.0 MIN-DEMAND: 0.0 MAX-DEMAND: 0.0 QUALIFY-RATE: ALL YEAR USE-MIN-QUAL: NO

METERED BILLING METERED BILLING ENERGY DEMAND ENERGY FIXED MINIMUM VIRTUAL TOTAL ENERGY ENERGY DEMAND DEMAND CHARGE CHARGE CST ADJ TAXES SURCHRG CHARGE CHARGE RATE CHARGE MONTH THERM THERM THERM/HR THERM/HR ($) ($) ($) ($) ($) ($) ($) ($/UNIT) ($) ------

JAN 673 673 14.9 14.9 667 0 0 0 0 29 0 1.0332 696

FEB 625 625 7.8 7.8 619 0 0 0 0 29 0 1.0365 648

MAR 662 662 7.1 7.1 656 0 0 0 0 29 0 1.0340 684

APR 726 726 7.3 7.3 719 0 0 0 0 29 0 1.0302 747

MAY 1142 1142 7.1 7.1 1131 0 0 0 0 29 0 1.0158 1160

JUN 476 476 7.4 7.4 472 0 0 0 0 29 0 1.0508 500

JUL 916 916 7.2 7.2 907 0 0 0 0 29 0 1.0219 936

AUG 1133 1133 7.1 7.1 1122 0 0 0 0 29 0 1.0160 1151

SEP 1250 1250 7.0 7.0 1239 0 0 0 0 29 0 1.0136 1267

OCT 871 871 7.2 7.2 863 0 0 0 0 29 0 1.0236 891

NOV 669 669 7.2 7.2 663 0 0 0 0 29 0 1.0335 691

DEC 487 487 7.0 7.0 482 0 0 0 0 29 0 1.0495 511 ======

TOTAL 9630 9630 14.9 9540 0 0 0 0 344 1.0264 9883 BCSD Nexton S3 FCU w/Turbocor DOE-2.2-47h2 7/10/2013 11:04:03 BDL RUN 2

REPORT- BEPS Building Energy Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY MBTU 0.0 0.0 0.0 5.7 955.7 0.0 24.6 398.9 0.0 0.0 0.0 0.0 1385.0

EM2 ELECTRICITY MBTU 1134.3 0.0 1364.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2499.0

FM1 NATURAL-GAS MBTU 0.0 0.0 0.0 963.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 963.0 ======

MBTU 1134.3 0.0 1364.7 968.7 955.7 0.0 24.6 398.9 0.0 0.0 0.0 0.0 4846.9

TOTAL SITE ENERGY 4846.93 MBTU 49.3 KBTU/SQFT-YR GROSS-AREA 49.3 KBTU/SQFT-YR NET-AREA TOTAL SOURCE ENERGY 12614.89 MBTU 128.3 KBTU/SQFT-YR GROSS-AREA 128.3 KBTU/SQFT-YR NET-AREA

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES. BCSD Nexton S3 FCU w/Turbocor DOE-2.2-47h2 7/10/2013 11:04:03 BDL RUN 2

REPORT- BEPU Building Utility Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY KWH 0. 0. 0. 1670. 280034. 0. 7205. 116891. 0. 0. 0. 0. 405799.

EM2 ELECTRICITY KWH 332337. 0. 399867. 0. 0. 0. 0. 0. 0. 0. 0. 0. 732205.

FM1 NATURAL-GAS THERM 0. 0. 0. 9630. 0. 0. 0. 0. 0. 0. 0. 0. 9630.

TOTAL ELECTRICITY 1138004. KWH 11.578 KWH /SQFT-YR GROSS-AREA 11.578 KWH /SQFT-YR NET-AREA TOTAL NATURAL-GAS 9630. THERM 0.098 THERM /SQFT-YR GROSS-AREA 0.098 THERM /SQFT-YR NET-AREA

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES. BCSD Nexton S3 FCU w/Turbocor DOE-2.2-47h2 7/10/2013 11:04:03 BDL RUN 2

REPORT- ES-D Energy Cost Summary WEATHER FILE- Charleston SC TMY2 ------

METERED TOTAL VIRTUAL ENERGY CHARGE RATE RATE USED UTILITY-RATE RESOURCE METERS UNITS/YR ($) ($/UNIT) ALL YEAR? ------

BEC Rate 30 ELECTRICITY EM1 EM2 1138004. KWH 127214. 0.1118 YES

SCE&G Rate 33 NATURAL-GAS FM1 9630. THERM 9883. 1.0264 YES

======137097.

ENERGY COST/GROSS BLDG AREA: 1.39 ENERGY COST/NET BLDG AREA: 1.39 BCSD Nexton S3 FCU w/Turbocor DOE-2.2-47h2 7/10/2013 11:04:03 BDL RUN 2

REPORT- ES-E Summary of Utility-Rate: BEC Rate 30 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: ELECTRICITY DEMAND-INTERVAL 30 3413. BTU/KWH BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: EM1 EM2 POWER-FACTOR: 0.80 EXCESS-KVAR-FRAC: 0.75 EXCESS-KVAR-CHG: 0.0000

JAN 84850 84850 376.7 376.7 6279 2354 0 0 0 188 0 0.1040 8821

FEB 81917 81917 426.6 426.6 6062 2667 0 0 0 188 0 0.1088 8916

MAR 96127 96127 489.7 489.7 7113 3061 0 0 0 188 0 0.1078 10362

APR 87079 87079 569.6 569.6 6444 3560 0 0 0 188 0 0.1170 10191

MAY 129579 129579 617.8 617.8 9589 3861 0 0 0 188 0 0.1052 13637

JUN 47608 47608 554.0 554.0 3523 3462 0 0 0 188 0 0.1507 7173

JUL 83677 83677 567.4 567.4 6192 3546 0 0 0 188 0 0.1186 9926

AUG 120735 120735 686.0 686.0 8934 4288 0 0 0 188 0 0.1111 13410

SEP 140054 140054 710.2 710.2 10364 4439 0 0 0 188 0 0.1070 14990

OCT 110953 110953 551.9 551.9 8211 3450 0 0 0 188 0 0.1068 11848

NOV 85247 85247 474.3 474.3 6308 2964 0 0 0 188 0 0.1110 9460

DEC 70178 70178 496.0 496.0 5193 3100 0 0 0 188 0 0.1208 8481 ======

TOTAL 1138004 1138004 710.2 84212 40752 0 0 0 2250 0.1118 127214 BCSD Nexton S3 FCU w/Turbocor DOE-2.2-47h2 7/10/2013 11:04:03 BDL RUN 2

REPORT- ES-E Summary of Utility-Rate: SCE&G Rate 33 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: NATURAL-GAS DEMAND-INTERVAL 60 100000. BTU/THERM BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: FM1

RATE-QUALIFICATIONS BLOCK-CHARGES DEMAND-RATCHETS MIN-MON-RATCHETS ------MIN-ENERGY: 0.0 Custom Gas Energy Blk1 MAX-ENERGY: 0.0 MIN-DEMAND: 0.0 MAX-DEMAND: 0.0 QUALIFY-RATE: ALL YEAR USE-MIN-QUAL: NO

METERED BILLING METERED BILLING ENERGY DEMAND ENERGY FIXED MINIMUM VIRTUAL TOTAL ENERGY ENERGY DEMAND DEMAND CHARGE CHARGE CST ADJ TAXES SURCHRG CHARGE CHARGE RATE CHARGE MONTH THERM THERM THERM/HR THERM/HR ($) ($) ($) ($) ($) ($) ($) ($/UNIT) ($) ------

JAN 673 673 14.9 14.9 667 0 0 0 0 29 0 1.0332 696

FEB 625 625 7.8 7.8 619 0 0 0 0 29 0 1.0365 648

MAR 662 662 7.1 7.1 656 0 0 0 0 29 0 1.0340 684

APR 726 726 7.3 7.3 719 0 0 0 0 29 0 1.0302 747

MAY 1142 1142 7.1 7.1 1131 0 0 0 0 29 0 1.0158 1160

JUN 476 476 7.4 7.4 472 0 0 0 0 29 0 1.0508 500

JUL 916 916 7.2 7.2 907 0 0 0 0 29 0 1.0219 936

AUG 1133 1133 7.1 7.1 1122 0 0 0 0 29 0 1.0160 1151

SEP 1250 1250 7.0 7.0 1239 0 0 0 0 29 0 1.0136 1267

OCT 871 871 7.2 7.2 863 0 0 0 0 29 0 1.0236 891

NOV 669 669 7.2 7.2 663 0 0 0 0 29 0 1.0335 691

DEC 487 487 7.0 7.0 482 0 0 0 0 29 0 1.0495 511 ======

TOTAL 9630 9630 14.9 9540 0 0 0 0 344 1.0264 9883 BCSD Nexton S4 WSHP DOE-2.2-47h2 7/10/2013 10:55:01 BDL RUN 1

REPORT- BEPS Building Energy Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY MBTU 0.0 0.0 0.0 3.8 836.4 20.2 61.1 386.6 0.0 0.0 0.0 0.0 1308.0

EM2 ELECTRICITY MBTU 1134.3 0.0 1364.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2499.0

FM1 NATURAL-GAS MBTU 0.0 0.0 0.0 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.6 ======

MBTU 1134.3 0.0 1364.7 4.3 836.4 20.2 61.1 386.6 0.0 0.0 0.0 0.0 3807.5

TOTAL SITE ENERGY 3807.54 MBTU 38.7 KBTU/SQFT-YR GROSS-AREA 38.7 KBTU/SQFT-YR NET-AREA TOTAL SOURCE ENERGY 11421.45 MBTU 116.2 KBTU/SQFT-YR GROSS-AREA 116.2 KBTU/SQFT-YR NET-AREA

PERCENT OF HOURS ANY SYSTEM ZONE OUTSIDE OF THROTTLING RANGE = 1.23 PERCENT OF HOURS ANY PLANT LOAD NOT SATISFIED = 0.00 HOURS ANY ZONE ABOVE COOLING THROTTLING RANGE = 7 HOURS ANY ZONE BELOW HEATING THROTTLING RANGE = 105

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES. BCSD Nexton S4 WSHP DOE-2.2-47h2 7/10/2013 10:55:01 BDL RUN 1

REPORT- BEPU Building Utility Performance WEATHER FILE- Charleston SC TMY2 ------

TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL ------

EM1 ELECTRICITY KWH 0. 0. 0. 1100. 245069. 5910. 17888. 113264. 0. 0. 0. 0. 383231.

EM2 ELECTRICITY KWH 332337. 0. 399867. 0. 0. 0. 0. 0. 0. 0. 0. 0. 732205.

FM1 NATURAL-GAS THERM 0. 0. 0. 6. 0. 0. 0. 0. 0. 0. 0. 0. 6.

TOTAL ELECTRICITY 1115436. KWH 11.349 KWH /SQFT-YR GROSS-AREA 11.349 KWH /SQFT-YR NET-AREA TOTAL NATURAL-GAS 6. THERM 0.000 THERM /SQFT-YR GROSS-AREA 0.000 THERM /SQFT-YR NET-AREA

NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES. BCSD Nexton S4 WSHP DOE-2.2-47h2 7/10/2013 10:55:01 BDL RUN 1

REPORT- ES-D Energy Cost Summary WEATHER FILE- Charleston SC TMY2 ------

METERED TOTAL VIRTUAL ENERGY CHARGE RATE RATE USED UTILITY-RATE RESOURCE METERS UNITS/YR ($) ($/UNIT) ALL YEAR? ------

BEC Rate 30 ELECTRICITY EM1 EM2 1115436. KWH 120521. 0.1080 YES

SCE&G Rate 33 NATURAL-GAS FM1 6. THERM 350. 59.2161 YES

======120871.

ENERGY COST/GROSS BLDG AREA: 1.23 ENERGY COST/NET BLDG AREA: 1.23 BCSD Nexton S4 WSHP DOE-2.2-47h2 7/10/2013 10:55:01 BDL RUN 1

REPORT- ES-E Summary of Utility-Rate: BEC Rate 30 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: ELECTRICITY DEMAND-INTERVAL 30 3413. BTU/KWH BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: EM1 EM2 POWER-FACTOR: 0.80 EXCESS-KVAR-FRAC: 0.75 EXCESS-KVAR-CHG: 0.0000

JAN 89785 89785 413.2 413.2 6644 2582 0 0 0 188 0 0.1049 9414

FEB 87263 87263 444.1 444.1 6457 2776 0 0 0 188 0 0.1080 9421

MAR 101904 101904 471.2 471.2 7541 2945 0 0 0 188 0 0.1047 10673

APR 89513 89513 484.9 484.9 6624 3031 0 0 0 188 0 0.1100 9842

MAY 125109 125109 535.2 535.2 9258 3345 0 0 0 188 0 0.1022 12791

JUN 42165 42165 414.7 414.7 3120 2592 0 0 0 188 0 0.1399 5899

JUL 71621 71621 419.3 419.3 5300 2620 0 0 0 188 0 0.1132 8108

AUG 102952 102952 541.1 541.1 7618 3382 0 0 0 188 0 0.1087 11188

SEP 125032 125032 542.5 542.5 9252 3390 0 0 0 188 0 0.1026 12830

OCT 115320 115320 510.5 510.5 8534 3191 0 0 0 188 0 0.1033 11912

NOV 90799 90799 462.7 462.7 6719 2892 0 0 0 188 0 0.1079 9798

DEC 73974 73974 477.3 477.3 5474 2983 0 0 0 188 0 0.1169 8645 ======

TOTAL 1115436 1115436 542.5 82542 35729 0 0 0 2250 0.1080 120521 BCSD Nexton S4 WSHP DOE-2.2-47h2 7/10/2013 10:55:01 BDL RUN 1

REPORT- ES-E Summary of Utility-Rate: SCE&G Rate 33 WEATHER FILE- Charleston SC TMY2 ------

RESOURCE: NATURAL-GAS DEMAND-INTERVAL 60 100000. BTU/THERM BILLING-DAY: 31 RATE-LIMITATION: 0.0000 METERS: FM1

RATE-QUALIFICATIONS BLOCK-CHARGES DEMAND-RATCHETS MIN-MON-RATCHETS ------MIN-ENERGY: 0.0 Custom Gas Energy Blk1 MAX-ENERGY: 0.0 MIN-DEMAND: 0.0 MAX-DEMAND: 0.0 QUALIFY-RATE: ALL YEAR USE-MIN-QUAL: NO

METERED BILLING METERED BILLING ENERGY DEMAND ENERGY FIXED MINIMUM VIRTUAL TOTAL ENERGY ENERGY DEMAND DEMAND CHARGE CHARGE CST ADJ TAXES SURCHRG CHARGE CHARGE RATE CHARGE MONTH THERM THERM THERM/HR THERM/HR ($) ($) ($) ($) ($) ($) ($) ($/UNIT) ($) ------

JAN 6 6 5.9 5.9 6 0 0 0 0 29 0 5.8428 34

FEB 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

MAR 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

APR 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

MAY 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

JUN 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

JUL 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

AUG 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

SEP 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

OCT 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

NOV 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29

DEC 0 0 0.0 0.0 0 0 0 0 0 29 0 0.0000 29 ======

TOTAL 6 6 5.9 6 0 0 0 0 344 59.2161 350

BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

5. -

System 1 - FCU with Ice (Four Pipe) Equipment Type Capacity Make/Model Number of UnitsCost Per Unit Total Cost LC FCU-18 1.5 tons Trane BCVC 9 $1,600 $14,400 20 FCU-24 2 tons Trane BCVC 62 $1,800 $111,600 20 FCU-36 3 tons Trane BCVC 7 $2,000 $14,000 20 FCU-48 4 tons Trane BCVC 4 $2,400 $9,600 20 FCU-60 5 tons Trane BCVC 2 $2,800 $5,600 20 FCU-240 20 tons Trane BCVC 1 $9,000 $9,000 20 DOAU-1 7,500 CFM AnnexAir - Dual Plate and Frame HX 3 $72,000 $216,000 20 DOAU-2 3,250 CFM AnnexAir - Dual Plate and Frame HX 1 $29,250 $29,250 20 DOAU-3 8,000 CFM AnnexAir - Dual Plate and Frame HX 1 $72,000 $72,000 20

Boiler -1/2 2000 CFH Aerco Benchmark 2 $30,000 $60,000 15 Chiller-1/2 155 tons ea Trane RTAC 2 $92,225 $184,450 25 Ice Storage 6@1500C Calmac 6 $14,760 $88,560 25 Heat Exchanger 925 GPM/500 tons 1 $48,320 $48,320 25 CWP-1/2 430 GPM/110 Ft Bell and Gosset 20 HP 2 $4,247 $8,494 20 GWP-1/2 465 GPM/90 Ft Bell and Gosset 20 HP 2 $5,562 $11,124 20 HWP-1/2 180 GPM/ 90 Ft Bell and Gosset 7.5 HP 2 $3,371 $6,742 20

Piping Aquatherm 1 $550,000 $550,000 Controls CMI 1 $580,000 $580,000

Total First Cost = $2,019,140

System 2 - FCU without Ice (Four Pipe) Equipment Type Capacity Make/Model Number of UnitsCost Per Unit Total Cost LC FCU-18 1.5 tons Trane BCVC 9 $1,600 $14,400 20 FCU-24 2 tons Trane BCVC 62 $1,800 $111,600 20 FCU-36 3 tons Trane BCVC 7 $2,000 $14,000 20 FCU-48 4 tons Trane BCVC 4 $2,400 $9,600 20 FCU-60 5 tons Trane BCVC 2 $2,800 $5,600 20 FCU-240 20 tons Trane BCVC 1 $9,000 $9,000 20 DOAU-1 7,500 CFM AnnexAir - Dual Plate and Frame HX 3 $72,000 $216,000 20 DOAU-2 3,250 CFM AnnexAir - Dual Plate and Frame HX 1 $29,250 $29,250 20 DOAU-3 8,000 CFM AnnexAir - Dual Plate and Frame HX 1 $72,000 $72,000 20

Boiler -1/2 2000 CFH Aerco Benchmark 2 $30,000 $60,000 15 Chiller-1/2 250 tons ea Trane RTAC 2 $140,185 $280,370 25

CWP-1/2 430 GPM/110 Ft Bell and Gosset 20 HP 2 $4,247 $8,494 20 HWP-1/2 180 GPM/90 Ft Bell and Gosset 20 HP 2 $3,371 $6,742 20

Piping Aquatherm 1 $500,000 $500,000 Controls CMI 1 $560,000 $560,000

Total First Cost = $1,897,056

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

System 3 - FCU without Ice (Turbocor Compressors) Equipment Type Capacity Make/Model Number of UnitsCost Per Unit Total Cost LC FCU-18 1.5 tons Trane BCVC 9 $1,600 $14,400 20 FCU-24 2 tons Trane BCVC 62 $1,800 $111,600 20 FCU-36 3 tons Trane BCVC 7 $2,000 $14,000 20 FCU-48 4 tons Trane BCVC 4 $2,400 $9,600 20 FCU-60 5 tons Trane BCVC 2 $2,800 $5,600 20 FCU-240 20 tons Trane BCVC 1 $9,000 $9,000 20 DOAU-1 7,500 CFM AnnexAir - Dual Plate and Frame HX 3 $72,000 $216,000 20 DOAU-2 3,250 CFM AnnexAir - Dual Plate and Frame HX 1 $29,250 $29,250 20 DOAU-3 8,000 CFM AnnexAir - Dual Plate and Frame HX 1 $72,000 $72,000 20

Boiler -1/2 2000 CFH Aerco Benchmark 2 $30,000 $60,000 15 Chiller-1/2 250 tons ea Smardt 2 $187,855 $375,710 25

CWP-1/2 430 GPM/110 Ft Bell and Gosset 20 HP 2 $4,247 $8,494 20 HWP-1/2 180 GPM/90 Ft Bell and Gosset 20 HP 2 $3,371 $6,742 20

Piping Aquatherm 1 $500,000 $500,000 Controls CMI 1 $560,000 $560,000

Total First Cost = $1,992,396

System 4 - Water Source Heat Pump Equipment Type Capacity Make/Model Number of UnitsCost Per Unit Total Cost LC FCU-18 1.5 tons Trane EXV 9 $2,640 $23,760 15 FCU-24 2 tons Trane EXV 62 $2,418 $149,916 15 FCU-36 3 tons Trane EXV 7 $3,166 $22,162 15 FCU-48 4 tons Trane EXV 4 $3,459 $13,836 15 FCU-60 5 tons Trane EXV 2 $4,158 $8,316 15 FCU-240 20 tons Trane EXV 1 $15,724 $15,724 15 DOAU-1 7,500 CFM AnnexAir - Dual Plate and Frame HX 3 $72,000 $216,000 20 DOAU-2 3,250 CFM AnnexAir - Dual Plate and Frame HX 1 $29,250 $29,250 20 DOAU-3 8,000 CFM AnnexAir - Dual Plate and Frame HX 1 $72,000 $72,000 20

Boiler -1/2 1500 MBH EA Aerco Benchmark 2 $25,000 $50,000 15 Cooling Tower-1 240 Tons Evapco ESWA 1 $150,000 $150,000 25

LWP-1/2 360GPM/90 Ft Bell and Gosset 20 HP 2 $3,983 $7,966 20

Piping Aquatherm 1 $225,000 $225,000 Controls CMI 1 $415,000 $415,000 Total First Cost = $1,398,930

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0 BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

5. – PRIORITY TOTAL YEAR-15 REPLACEMENT YEAR-15 ESENT REPLACEMENT PRESENT PRESENT 7722,242,400 577,000 371,000 4,362,030 1 65,3592,899,800 ------5,423,740 4 53,3802,687,100 ------5,058,456 3 44,5042,528,400 ------5,018,896 2 ANNUAL COSTS ANNUAL HVAC OPTION HVAC SUMMARY BERKELEYCOUNTY ANALYSIS SCHOOL DISTRICT HVAC CAPITAL COST CAPITAL ($) ($) ($) ($/YR) ($/YR) ($/YR) ($/YR) ($) ($) ($) ($) COST COSTS COST GAS COST COST ANNUAL VALUE COST VALUE VALUE 2,019,140 504,800 2,523,940 9,543 145,316 10,500 1 1,897,056 474,300 2,371,356 9,540 133,839 10,000 1 1,992,396 498,100 2,490,496 9,540 124,964 10,000 1 1,398,930 349,700 1,748,630 --- 118,272 8,500 126, CONSTRUCTION SOFT PROJECT NATURAL ELECTRIC MAINT. TOTAL PR FourPipe Coil Fan withStorage Ice FourPipe Coil Fan without Storage Ice FourPipe Coil Fan without StorageIce TurbocorChiller Water Source Water HeatPump BASE ALT -1 ALT ALT - 2 - ALT ALT - 3 - ALT OPTION DESCRIPTION

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0

BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

5. –

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0

March 20, 2013

Berkeley County School District 2226 Old Highway 52 Monks Corner, South Carolina 29461

Attention: Ms. Connie Myers

Reference: Nexton Elementary School HVAC System Code Compliance

Dear Connie:

As the design for the Nexton Elementary School project moves forward, RMF felt that it would be prudent to discuss the code compliance of the suggested mechanical system.

For Cane Bay Elementary School (CBMS), RMF was directed by the Berkeley County School District to provide indoor 4-ton, 4-pipe fan coil units with outdoor air ducted directly to the return side of the fan coil unit, and to design the HVAC systems for an indoor relative humidity condition of 60 percent.

For the CBMS HVAC system dehumidification of ventilation air is accomplished through the following design strategy:

ANSI/ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality, requires the HVAC system to continuously provide a minimum ventilation rate of 10 cfm/person and 0.12 cfm/ft 2 in classrooms. For this ventilation strategy the Fan Coil Unit must be energized whenever the building is occupied. This standard has been adopted by the International Mechanical Code and dictates the quantity of outdoor air required for the classrooms that must be provided and dehumidified by the fan coil units. For a typical classroom this equates to approximately 350 CFM.

Most fan coil units are designed to maintain the dry-bulb temperature in the space (temperature) and not the wet-bulb temperature (moisture). During most of the year the fan coil unit will operate in part load conditions, where the sensible cooling loads are considerably less than the peak design conditions the unit was selected for. Constant- volume systems respond to part-load conditions by reducing coil capacity (which raises the temperature of the coil surface and of the supply air), therefore the coil surface will not be colder than the dew point and sensible cooling without dehumidification will occur.

In order to achieve some level of dehumidification, active dehumidification control must be provided. For this system active humidity control is achieved by automatically and continuously resetting the cooling and reheat coils' leaving air temperatures as needed to manage both the temperature and relative humidity sensed in the space. This

194 Seven Farms Dr., Suite G OFFICE 843.971.9639 Charleston, South Carolina 29492 WEB rmf.com Berkeley County School District, Page 2 March 2, 2013

requires that temperature control of the unit be overridden by a humidity sensor, and for the cooling water valve to open fully to sub-cool the mixture of outdoor and return air. The reheat coil then is required to reheat the air leaving the cooling coil as necessary to maintain the zone’s cooling set point, resulting in simultaneous heating and cooling.

As of January 1, 2013 the state legislature has adopted the 2009 International Energy Conservation Code which references ASHRAE 90.1-2007. The adoption of the more recent code makes the CBMS system difficult to install in new projects due to code compliance issues with simultaneous heating and cooling of the supply air. I have included an excerpt from ASHRAE 90.1-2007 which outlines the mandatory requirements.

6.5.2 Simultaneous Heating and Cooling Limitation

6.5.2.1 Zone Controls. Zone thermostatic controls shall be capable of operating in sequence the supply of heating and cooling energy to the zone. Such controls shall prevent

1. reheating, 2. recooling, 3. mixing or simultaneously supplying air that has been previously mechanically heated and air that has been previously cooled, either by mechanical cooling or by economizer systems, and 4. other simultaneous operation of heating and cooling systems to the same zone.

Exceptions: a. Zones for which the volume of air that is reheated, recooled, or mixed is no greater than the larger of the following: 1. the volume of outdoor air required to meet the ventilation requirements of Section 6.2 of Standard 62.1 for the zone, 2. 0.4 cfm/ft2 of the zone conditioned floor area, 3. 30% of the zone design peak supply rate, 4. 300 cfm—this exception is for zones whose peak flow rate totals no more than 10% of the total fan system flow rate, or 5. any higher rate that can be demonstrated, to the satisfaction of the authority having jurisdiction, to reduce overall system annual energy usage by offsetting reheat/recool energy losses through a reduction in outdoor air intake for the system.

The CBMS classroom configuration utilizes a 1400 CFM fan coil unit with 350 CFM of outdoor air. In order to meet the requirements of ASHRAE 90.1 the unit must be provided with a control strategy that meets one of the five (5) exceptions. In order to meet the exceptions the fan coil unit which comes standard as a constant volume airflow unit must be reconfigured to be a variable volume airflow unit in order to reduce the airflow to 30 percent of the design flow. This will require that a VFD be provided for each fan coil unit. The reduction of airflow below 50 percent of the design flow however forces the fan to operate at or near the unstable region on the fan curve which will cause motor failures and maintenance issues.

Berkeley County School District, Page 3 March 2, 2013

Due to the current code requirements and equipment limitations RMF cannot suggest the use of indoor 4-pipe fan coil units with outdoor air ducted directly to the return side of the fan coil unit. The outdoor air will now have to be decoupled from the fan coil and ducted directly to the space.

RMF understands the potential cost impact of providing a decoupled dedicated outdoor air system and we have been told of BCSD’s past problems with direct expansion dedicated outdoor air units. We would appreciate the opportunity to meet and determine, with your input, a code compliant system that will satisfy your current and future needs.

Thank you for your cooperation in this matter.

Sincerely,

RMF ENGINEERING, INC.

Seth Spangler, PE, LEED AP Project Manager

BERKELEY COUNTY SCHOOL DISTRICT HVAC SYSTEM ANALYSIS

5. –

FIRM BACKGROUND

The firm of RMF Engineering, Inc. (RMF) is a 230 person consulting firm specializing in building and infrastructure systems engineering. RMF is nationally recognized for the analysis, planning, design, and commissioning of buildings and campus utility generation and distribution systems. RMF's production offices are located in Charleston, South Carolina; Baltimore, Maryland; Albany, New York; Durham, North Carolina; Boston, Massachusetts; Columbus, Ohio; and Charlottesville, Virginia.

The full time staff is composed of 60 licensed professional engineers and over 90 engineering college graduates. The firm was established to provide various communities with responsive and quality engineering services.

RMF was established in 1983 as primarily a mechanical / electrical engineering firm. Its initial focus included two areas of expertise: 1) Central utility plants and distribution systems for healthcare, university / college, government, and institutional campuses; and 2) MEP design of research, healthcare, and educational facilities. Other services now include environmental (Air Pollution) engineering , civil and structural engineering, commissioning, operations and maintenance training, plant operations, asbestos and lead paint testing and abatement design, emissions testing, and non-destructive testing.

Effective communications with the Owner, consultants and other management parties are essential for a successful project. RMF is dedicated to effective and continuous project communications.

HVAC EXPERIENCE

System designs are always tailored to the specific design criteria of the project. RMF has designed multiple projects in every specific area required for this project. The majority of our HVAC projects have included detailed system analyses and master planning prior to the initiation of design efforts. HVAC renovations have included educational, institutional, industrial, maintenance, governmental and commercial type projects. Work orders range in size from a few thousand square feet up to complete system replacements.

All of the HVAC projects are approached from an initial qualitative as well as quantitative system analysis utilizing computerized peak load determination and annual operating costs. Various systems are life-cycle costed utilizing present worth analysis. The level of system sophistication and operator capability are always considered in the final HVAC system selection to insure adequate and proper performance and maintainability. The firm can provide a variety of automatic temperature control system approaches ranging from electric, electronic, pneumatic, to direct digital (DDC) technologies. RMF has been the prime consultant for over 500 HVAC renovation projects. RMF's experience has included many laboratory and test facilities which utilize electronic equipment for testing, analytical research, and data processing.

RMF Engineering, Inc. 07/29/2013 Final Report RMF No. 313069.A0