Model for Energy Efficiency

2017 ASHRAE TECHNOLOGY AWARD CASE STUDIES 35 Years of Excellence University Lab Model for Energy Efficiency

FIRST PLACE EDUCATIONAL FACILITIES,NEW The teaching and research lab brings together undergraduate labs and faculty research in the biology, chemistry, neuroscience, and bio- physics departments and provides a student commons area. It was the first major construction following an initiative to reduce car- bon emissions by 51% by 2025. BY BRADFORD CROWLEY, P.E. Energy Efficiency Energy consumption in a laboratory is driven by outdoor air (OA) requirements, the heating and cool- JEFFREY TOTARO JEFFREY

© ing to condition this air, and high BY BRADFORD CROWLEY, P.E., MEMBER ASHRAE internal heat gains from laboratory equipment. The 105,000 gross eeting sustainability goals in a lab with 142 ft2 (9755 gross m2) Undergraduate Teaching Laboratories (UTL) build- fume hoods is a huge challenge for design ing uses a number of technologies, engineers. It’s an even taller order when strategies, and systems specifically those labs require the flexibility to change designed to mitigate the energy Mrapidly, such as from a wet lab to a dry one. Both were the impact of these drivers including: case for the new Undergraduate Teaching Laboratories at • Enthalpy and sensible energy recovery wheels to deliver neutral Johns Hopkins University (JHU). temperature ventilation air; Designers met those goals, creating a building that • Chilled beams, radiant floor used 50% less energy in 2016 compared to ASHRAE heating, and perimeter radiators; Standard 90.1-2007’s baseline. This helped the building • Waterside economizer using air- earn LEED Platinum certification. handling unit (AHU) cooling coils (free winter cooling); • District energy from campus Bradford Crowley, P.E., is an associate principal and team leader at Ballinger in Philadelphia. trigeneration plants;

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ABOVE Radiant floor and passive chilled beams in the commons. LEFT Exposed utilities, ceiling clouds, point

HALKIN/MASON LLC PHOTOGRAPHY ARCHITECTURAL exhaust. © PHOTOS

• High-efficiency lighting and reheat, neutral supply air allows compared with a glycol run- daylighting with occupancy sensor displacement makeup air delivery around recovery system. Together controls; system that significantly reduces with airflow-saving technolo- • High performance fume hoods; ductwork. Ducted air was sized only gies, the peak heating and cool- • Occupancy based airflow reset; as required to drive chilled beam ing was reduced by 4,000 MBH • “Decommissioning switches” to cooling. (1.2 MW) and 500 tons (1758 kW). turn off airflow to vacant labs; and Exhaust venturi valves maintain Figure 2 shows how reheat is elimi- • High performing envelope and the required exhaust flow (fume nated if air is supplied at a neu- minimal east/west glazing. hood flow and minimum air change tral temperature. In traditional Energy use is shown in Table 1. rate) in each laboratory. Exhausts systems, reheat is required when In 2016, energy consumption of on each floor are summed, and airflow requirements exceed the 144 kBtu per gross ft2 (1635 MJ large floor-based supply valves cooling requirement; this occurs per gross m2) was lower than the introduce the balance of the floor’s frequently in labs with high air modeled design, 192 kBtu per makeup air (minus ducted chilled gross ft2 (2180 MJ per gross m2), beam air) into a pressurized ple- BUILDING AT A GLANCE which confirmes a 50% cost sav- num above the corridor ceiling. ings over ASHRAE Standard 90.1- The makeup air is passively pulled Undergraduate 2007’s baseline of 408 kBtu per through large displacement grilles, Teaching gross ft2 (4633 MJ per gross m2). with fabric backdraft dampers that The installed air-handling system balance pressures between the Laboratories (Figure 1) uses two energy recovery plenum and labs. This air delivery wheels: a 3A molecular sieve-coated concept inherently creates a low- Location: Baltimore, Md. media enthalpy wheel and a sen- pressure, high-volumetric offset Owner: Johns Hopkins University sible wheel. The two wheels act to that ensures each laboratory is Principal Use: Teaching and research laboratories recover exhaust energy and reheat negatively pressurized with respect air toward a neutral temperature. to the corridor. It also significantly Includes: Teaching labs, research labs, vivarium, offices This design decouples ventilation simplifies controls, improves the requirements from heating/cooling quality of the building design via Employees/Occupants: 136 FTE/340 student demands. Active chilled beams pro- minimizing ductwork, and elimi- Occupancy: 90% vide sensible cooling throughout the nates dumping of cold (or reheated) building, while perimeter radiation air.1 Gross Square Footage: 105,000

offsets envelope heating losses. Dual energy recovery wheels Substantial Completion/Occupancy: July 2013 Because ventilation air is kept at have a large impact on system 68°F (20°C), reheat coils are not sizing. At the installed design air- National Distinctions/Awards: LEED Platinum required at supply terminals. In flow, the dual wheel system saves addition to reducing/eliminating 300 tons (1055 kW) of cooling

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change rates (ventilation driven) or densities of TABLE 1 Monthly and annual building utility consumption. 2 fume hoods (hood driven). ENERGY CONSUMPTION Table 2 compares terminal loads and flows for two FISCAL YEAR 2016 ELECTRICITY (KWH) STEAM (MMBTU) CHILLED WATER (TON·HR) common lab modules, a biology lab and an organic July 224,207 124 124,583 chemistry teaching lab. The analysis demonstrates how reheat is nearly eliminated in the building. It August 224,433 173 105,333 also highlights the difference in ducted supply air that September 237,029 252 93,667 results from the combination of chilled beams, high October 233,478 403 31,333 performance fume hoods, and displacement systems. November 225,093 372 23,917 Overall, the total AHU capacity is 30% smaller than a December 201,002 367 21,167 baseline system, and approximately 40,000 cfm (18 January 198,870 563 4,833 878 L/s) of this air is delivered via the plenum. Fully- February 217,971 886 8,833 ducted supply air for the building is less than 0.6 cfm March 225,427 486 20,667 per gross ft2 (3 L/s per gross m2). April 226,507 439 31,583 To maximize performance, a manifolded exhaust system combines general and fume hood exhaust prior to May 215,665 341 47,000 the recovery system. While the use of wheels was criti- June 207,635 179 94,167 cal to this building’s impressive energy savings, risks TOTAL 2,637,315 4,585 607,083 of cross-contamination, vis-à-vis fume hood exhaust, had to be eval- High Momentum uated. Fortunately, the owner, with Exhaust Fans AHU With Dual Energy Recovery Wheels 25 years’ experience and 3 million

cfm (1.4 million L/s) of installed Wheel Wheel wheel capacity in laboratory appli- cations, had expertise on this topic. Together with Johns Hopkins Supply Duct University safety officers (JHU Exhaust Duct Health Safety and Environment), Displacement Grille Supply the design team was able to evalu- Plenum ate and approve the use of wheels early in design. This process Active Chilled Beam included review of the building’s Hallway HVAC systems, the lab’s safety High Performing Perimeter Heat Fume Hood protocols, equipment specifica- tion and commissioning require- FIGURE 1 HVAC systems concept. ments, and an analysis of expected research and chemical use (including spill scenarios). Indoor Air Quality (IAQ) and Thermal Comfort The wheel manufacturer was sole-sourced based on While energy efficiency was an important driver in testing of desiccants cross-contamination approved design, laboratory safety and indoor environmental by the safety officer that limited the maximum car- quality were paramount. The design team met regularly ryover to 0.045% per wheel (0.09% for two wheels with officers from JHU Health Safety and Environment in series). Prior to occupancy, the system was com- to review design, set standards, and investigate new missioned and verified via a tracer SF6 gas test, in technologies. This process ensured that the laboratories accordance with ASHRAE Standard 84-2008, Method of exceeded all safety requirements and provided new Testing Air-to-Air Heat/Energy Exchangers. See “Code and direction for future lab designs at the campus. Safety Concerns Using Desiccant Wheels” for more on High performance fume hoods were used to reduce wheel safety. airflow. Hood velocities were designed to maintain

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65 fpm (0.33 m/s) at 18 in. (457 mm) sash height versus the standard 100 fpm (0.51 Process 1 to 2: Enthalpy Wheel Process 2 to 3: Coiling Coil m/s). The hood was witness-tested at the Process 3 to 4: Sensible Wheel factory, by owner and engineer, to pass Process 4 to 5: Room Loads ASHRAE Standard 110-1995, Method of Testing 140 Performance of Laboratory Fume Hoods (8L as Cooling Load: manufactured 0.05 factory test pass crite- 2.7 tons/1,000 cfm 1 Outdoor Air: 120 95°F DB, 78°F WB ria) with a full open sash (27 in. [686 mm] 100 at 45 fpm [0.23 m/s]), as well as at the 18 2 80 in. (457 mm) operating height. This test 5 Room Condition: 74°F DB, 50% RH 60 was essential before acceptance because it 3 4 Humidity Ratio (Grains) proved containment under conditions in 40 which occupants (undergraduate students) could potentially operate fume hoods. In addition, 100% of the 142 fume hoods were 40 50 60 70 80 90 100 Dry-Bulb Temperature (°F) ASHRAE Standard 110 field-tested (4L as FIGURE 2 Neutral temperature air-handling system with dual energy recovery wheels. installed 0.1 pass criteria). Teaching labs were designed with adjacent prep spaces so TABLE 2 Lab module load comparison. BASELINE SYSTEM—ALL AIR chemicals could be removed HIGH PERFORMANCE FUME HOODS AND NEUTRAL AIR CHILLED BEAM SYSTEM FUME HOOD 55°F SUPPLY VAV FUME HOODS from the teaching environ- OCCUPANCY SASH POSITION SUPPLY AIR REHEAT LOAD DUCTED SUPPLY DISPLACEMENT REHEAT CHILLED BEAM ment daily. This served to (CFM) (MBH) AIR (CFM) SUPPLY AIR (CFM) LOAD (MBH) LOAD (MBH) enhance safety and allowed ORGANIC CHEMISTRY TEACHING LAB MODULE: 32 FOUR-FOOT FUME HOODS + FOUR 6 IN. FUME HOODS the design team to reduce the Unoccupied Closed 5,250 97 0 5,250 23 0 minimum air change per hour Occupied Open 19,390 321 1,400 10,670 2 0 (ach) rates to 3 ach when unoccupied (from 6 ach when occu- Occupied Closed 5,250 31 1,400 3,850 0 42 pied). In addition, a switch was BIOLOGY TEACHING LAB MODULE: FOUR 6 IN. FUME HOODS provided to shut off air when Unoccupied Closed 1,150 13 0 1,150 0 0 labs are unoccupied for long Occupied Open 4,350 13 1,400 1,350 0 59 periods, which is often the Occupied Closed 3,725 0 1,400 1,350 0 59 case in teaching laboratories. 1. A minimum of 6 air changes per hour (ach) occupied. Three ach unoccupied. Fume hood airflows override these minimums as required. Module area This easy-to-use device was is 3,200 ft2. 450 cfm transfer air assumed. 2.. Fume hoods: Baseline of 100 fpm at 18 in. sash, High performing hoods at 65 fpm at 18 in. sash. Flows when closed for both systems were set above developed and integrated into the ANSI Z9.5 minimum of 150 ach inside the hood. the control system allowing 3. Unoccupied periods internal and external load of 1 W/ft2. Occupied periods at 7 W/ft. the professor/lab manager to decommission the lab using a key. Safety measures such a post-occupancy smoke visualization was performed to as a red light and signage are used to indicate when labs demonstrate air movement, ventilation effectiveness, are decommissioned.4 and pressurization relationships. Laboratories were designed so air cascades across the The exposed concrete structure creates a high thermal space, with displacement grilles located near the entry inertia building with a stable mass that helps mitigate to sweep air toward the general exhaust in the back. A fluctuations in temperature and radiant asymmetry. representative portion of a typical laboratory was con- Perimeter radiation was used at all window exposures to structed at the chilled beam manufacturer’s laboratory. offset winter conduction losses, and a radiant floor heat- The engineer developed a test to prove performance ing system was installed in the commons to enhance and air quality, specifically near fume hoods, which was comfort in the 20 ft (6.2 m) high space. To prevent witness-tested by the owner and engineer. In addition, condensation on chilled beams and piping, humidity

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is tightly controlled under 56°F (13°C) dew point (<55% RH). Space air temperatures are maintained between Code and Safety Concerns 72°F and 74°F (22°C and 23°C). Using Desiccant Wheels When considering desiccant wheels in laboratories, Innovation design teams must consider a number of codes and The building’s real innovation was not the technolo- standards including requirements outlined for Inter- gies and systems themselves, but rather how these national Mechanical Code (IMC) hazardous exhaust, systems complement each other and integrate with the National Fire Protection Association, ANSI/AIHA/ASSE architecture to simplify design, maintain space quality, Z9.5, American National Standard for Laboratory Ventilation, and offset construction costs via standardization. The and ASHRAE Standard 62.1 air classifications. If fume hood exhausts are considered hazardous per IMC, Undergraduate Teaching Laboratories was as an addi- manifolding exhaust from separate control zones is tion to an existing building, and matching floor-to-floor restricted and exhaust recovery is often not allowed or heights (13 ft, 4 in. [4.1 m]) was a significant challenge. is cost prohibitive.3 ASHRAE Standard 62.1-2007 classi- The neutral air displacement system, combined with fies fume hood exhaust as Class 4 air and restricts (any) chilled beams and high performance fume hoods, recirculation of this air. This effectively would prohibit greatly reduced ductwork size, allowing for repeatable the use of energy wheels due to cross-contamination. distribution and ceiling clouds located 9 ft, 4 in. (2.8 m) An addendum was included with Standard 62.1-2013 above finished floor in all laboratories, including those that allows a responsible environmental health and with high fume hood densities. safety (EH&S) professional to reclassify fume hood exhaust as Class 3 based on an evaluation of chemi- The systems were designed for flexibility and adapt- cals used, total exhaust volume, systems used, and the ability to accommodate rapidly changing convergent resultant concentrations at the energy recovery device. science teaching and research where space types change With Class 3 air, up to 5% recirculation is allowed; how- between wet and dry, classroom and laboratory, and ever, when the fume hood exhaust class is lowered, this interdisciplinary and multidisciplinary work. The author recommends specifying wheels that have been chilled beam design, for example, was standardized in independently tested to limit cross contamination to less than 0.1%. all labs. This allows a wet laboratory to be converted to dry (and vice versa) by altering the general exhaust and displacement airflow rates, but no physical changes to Neutral Temperature Air the distribution system (ducts, chilled beams, air valves, With Energy Recovery etc.) are required. This standardization and flexibility Chilled Beam ensures energy performance is not compromised in Occupancy Sensor future modifications. Daylight Sensor High Performance Operation and Maintenance Fume Hood Rain Process Chilled Water HVAC equipment was centralized to reduce mainte- Garden nance. Three large AHUs located in a penthouse pro- vide supply air throughout the building. Valve galleries Network Vacuum System are located next to shafts to house venturi exhaust air Perimeter Radiation valves, rather than locating them overhead (Photo 2). PHOTO 1

Innovations used to enhance performance and create a quality environment. HALKIN/MASON LLC PHOTOGRAPHY ARCHITECTURAL

Supply air terminals (VAV boxes and venturi valves) © were designed for easy access and located in the corridor outside the laboratory (Figure 3). Within the labs, of the new technologies used were thoroughly reviewed ceilings were left exposed to structure, allowing for easy with the owner during the design process. access to utilities. The labs were designed using a modu- lar approach, where utility pathways, sizes, and shutoff Cost Effectiveness locations were all standardized. This provides familiar- The design process allowed the proposed systems to be ity that simplifies maintenance. The maintenance needs optimally integrated with the building’s architecture,

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Biology Teaching Exhaust Valve Closet Organic Teaching Module Module (Four per Floor) Legend

Makeup – Air Plenum

Displacement Grille

Exhaust Duct

Supply Duct

BALLINGER PHOTO 2 Exhaust valve closet. FIGURE 3 Typical floor plan and distribution strategy. Displacement system reduces ductwork. ©

which minimized the cost penalty future environmental efforts and 2. Labs21. 2004. “Best practice guide: minimizing reheat energy use in laborato- for using energy-efficient technolo- help the university achieve its car- ries.” http://tinyurl.com/y9othvc5. gies (Refer to Table 2 for ducted air- bon reduction goals. 3. Barnet, B. 2013. “Energy recovery in flows). For example, the high perfor- lab air-handling systems.” ASHRAE Journal mance fume hood and the makeup Conclusion 55(9):20 – 34. 4. Hock, L. 2015. “Giving power to the air displacement distribution system The visibly and functionally people.” Laboratory Design. http://tinyurl. saved ductwork, air handling, and “green” building is a model for com/yc3joz9a. central cooling/heating plant capac- energy efficiency, sustainable site ity (off-site). Other technologies, development, and interior environ- such as the energy wheels, had a mental quality. The iconic building high first cost, but the payback was has become a compelling draw for

RP-1673 quick. Overall, the combined pre- students, faculty, and the wider ASHRAE Design Guide for Tall, Supertall, and Megatall Building Systems The Guide to Meeting the Challenges of Tall Buildings

Tall buildings present unique and formidable challenges to architects and engineers ASHRAE Design Guide for mium for all the energy-efficiency campus community.because of their size, location in major urban areas, and the multiple, complex occupancies they often contain. ASHRAE Design Guide for Tall, Supertall, and Megatall Building Systems is a unique reference for owners; architects; and mechanical, structural, and electrical engineers as well as other specialized consultants involved in designing systems for these buildings. Tall,

measures (wheels, chilled beams, Expanded since ASHRAE’s previous guide on the topic in 2004, this new design guide covers not only tall buildings (taller than 300 ft [91m]) but now also addresses supertall (taller than 984 ft [300 m]) and megatall (taller than 1968 ft [600 m]) buildings, with a Supertall, broadened scope and updated content that reflects current standards and industry practices.

lights, roof insulation, lighting, etc.) Acknowledgements This guide not only focuses on the efforts of designers of the HVAC systems but also addresses the importance of the design team and their collective efforts and concerns that are the critical elements in determining the ultimate solutions to the project needs of a tall and Megatall building. This guide addresses design issues for tall commercial buildings, which are very often mixed use, with low-level retail, office floors, residential floors, and hotel floors. Building Systems was estimated to be less than 2% of The success of thisMajor sectionsproject cover the following subjects: would • Architectural design • Façade systems • Climate data • Indoor air quality (IAQ) and thermal comfort the building cost, and the payback not have been possible• HVAC systems without the • Electrical system interfaces Peter Simmonds • Intelligent buildings and controls • Water distribution • Plumbing systems

• Energy modeling and authentication was approximately four years. free sharing of ideas• Vertical and transportation research • Life safety Simmonds • Needs of residential occupancies

Also included are appendices with examples of stack effect and wind pressure for four from individuals, manufacturers,representative climates, energy analysis examples, and HVAC design criteria and a systems description for a multiple-tenant office building.

ASHRAE Design Guide for Tall, Supertall, and Megatall Building Systems is accompanied by online content, which can be found at www.ashrae.org/tallbuildings. Environmental Impact and organizations such as ASHRAEISBN 978-1-936504-97-8

1791 Tullie Circle Atlanta, GA 30329-2305 9 781936 504978 Telephone: 404-636-8400 (worldwide) The building and its HVAC systems and I2SL (formerly Labs21).www.ashrae.org On theProduct code: 90132 6/15

Tall, Supertall, Megatall Buildings Hard cover.indd 1 6/4/2015 11:18:38 AM clearly demonstrate the university's manufacturer’s side, John Fischer $120 ($98 ASHRAE Member) commitment to sustainability. With and Gordon Sharp have had seminal an energy savings of over 50% (cost roles in developing and popularizing The Guide to and EUI), and an annual avoidance the technologies that this project of almost 2,000 metric tons of CO2, depended upon. Thanks to their Meeting the which is far from common even work, and to all the others who work by green building standards, this to create energy-efficient and safe Challenges of building raises the bar on laboratory laboratory systems. energy performance and challenges Tall Buildings preconceptions of laboratory energy References 1. Bartholomew, P. 2004. “Makeup intensity. The buildings’ success air heat recovery: saving energy in labs.” www.ashrae.org/megatall and proven reliability will facilitate ASHRAE Journal 46(2):35 – 40. www.info.hotims.com/65140-90

JULYTall, Supertall, 2017 Megatallashrae.org Buildings ASHRAE6th Pg V.indd JOURNAL 1 5/23/2016 10:53:0331 AM