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WHAT WILL WE COVER ?

 Controls  Basic Types  Inputs & Outputs  Technologies  Pneumatic BUILDING AUTOMATION AND CONTROL  Electric  DDC SYSTEMS  Terminology SECTION V  PID Cont ro ls  Review  Building Automation Systems for Energy Management  Basic Functions  Programs  Review

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BASIC TYPES BASIC FEEDBACK CONTROL SYSTEM

 Manual CONTROLLER SET POINT Switches RC Dimmers

ACTUATOR

 SENSOR  Open Loop Automatic CONTROLLED DEVICE Timer T

 Closed Loop Automatic AIR FLOW Thermostat Humidistat HEATING COIL Dimmable Ballast w/Photosensor

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BASIC TYPES BASIC INPUTS & OUTPUTS

 Two Position  Binary or Digital (D)  The system is either OFF or ON (gas furnace).  Signal with two states or positions which can be  Accomplished with a relay whose contacts are either open or closed, or a valve whose stem position is incremental (on-off, day-night, open-closed, occupied- either open or closed. unoccupied, series of 1’s & 0’s)

 Proportional  Analog (A)  A variation from the set point produces a proportional movement in the actuator.  Signal can be monitored or controlled through a  Pneumatic controls vary the air pressure. range of positions or values (0 to 50o C, 20 to 35 kPa, 0  Electric controls use a potentiometer (a type of to 10 VDC,4 to 20 milliamps) variable resistor).

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Input Examples Inputs & Outputs Analog Digital

Input Points TemperatureAI Relative HumidityAI FlowAI / DI Pressure AI Status or ProofAI / DI Air Quality AI

Low Temp. Detector End Switch Outside Air Temp. Sensor Digital Input Digital Input Analog Input Output Points Motors for Pumps / FansDO Valves AO LightsDO Dampers AO Variable Speed Drives AO Lighting ContactorsDO (or digital) LANDIS & GYR Smoke Detector

Room Temperature Sensor High Pressure Detector Duct Smoke Detector Analog Input Digital Input Digital Input

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Inputs & Outputs BASIC TECHNOLOGIES

 Pneumatic

 Electric 1.VFD Start/Stop DO 2.VFD Speed AO Signal Variable Air Volume  Direct Digital Control (DDC) System

4.High Static Cutout

3.Air Flow AI DI 5.Static AI Press

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PNEUMATIC CONTROLS PNEUMATIC CONTROLS

 Use clean, dry, oil-free compressed air to operate the control system.  Have been used in many HVAC applications. Advantages

Main Air Line  Are well understood by many designers and most maintenance people.  Are inherently proportional and very reliable. Branch Air Line  Were relatively inexpensive in the past.

Controller Air Compressor Disadvantages Hot Water Supply  Not very precise. Analog Signal  Typically required frequent calibration. Hot Water Valve Supply Air Sensor  Pneumatic control algorithms are hard to change. Outside Air H typically pre-set by manufacturer C ( ) Heating Supply Fan Coil

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ELECTRIC CONTROLS ELECTRIC CONTROLS

 Can be analog electric or electronic controls. Advantages  Use a variable, but continuous, electrical voltage or  Can be very accurate and very stable. current to operate the control system.  Do not require field calibration, and are drift-free, if  Transmit signals good quality sensors are used. quickly and accurately.  Relatively easy to implement proportional plus integg()ral (PI) control electronicall y.

Disadvantages  Difficult to interchange parts easily because of the many different systems.  Do not interface directly with our digital computers

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DIRECT DIGITAL CONTROLS DIRECT DIGITAL CONTROLS  Use electrical pulses to send signals. Advantages  Interface directly with microprocessors, directly &/or via the  Algorithms can be adjusted relatively easily after internet using TCP/IP. installation  Precise  No controller drift, recalibration is normally not necessary  Cost effective (similar to electronics market)

Disadvantages  Possibly not well understood by O&M staff  Different communication protocols, interface standards, and internal logic are typically complex (BACNET-ASHRAE 135-2008; and Lonworks – Lonmark Corporation; are both addressing these interface problems)

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WEB BASED ENERGY INFORMATION CONTROL ALGORITHMS AND CONTROL SYSTEMS  PID Controls  TCP/IP is Transmission Control Protocol/Internet Protocol  P is proportional  Internet Explorer, Netscape Navigator, Mozilla Firefox all take TCP/IP input  I is integral  Many submeters now have data accumulators that have URL  D is derivative addresses, and send data by TCP/IP over Local Area Networks  Controls are usually P, PI or PID  This data will come into your PC in standard spread sheet format  PID is cons idere d t he best o f thi s group for you to use as you like  Newer control algorithms are:  You can make charts, graphs, tables, etc in Excel or other common SS programs  Fuzzy logic  You now have your own web based energy information system  Learning systems  And it doesn’t cost you a fortune. Save your money for the really  Self-optimizing systems fancy analysis and diagnostic systems that many companies can provide to you

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PID Controls Loop Response PID Controls Loop Definitions

Stability Stable if process doesn't show continuing trend away from setpoint or continuous oscillation following an upset in either load or setpoint

Response Time required for PV to reach SP following a step change in mode or setpoint Time Overshoot The amount the PV goes beyond the SP following a change in load or setpoint

Offset The amount of constant error existing between PV and SP once the process reaches steady state

Settling Time Time required for process to reach steady state following a change in load or setpoint

Steady State Condition that exists in closed loop system when the control variable (CV) equals a constant value and no oscillation occurs

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PID Controls REVIEW: Summary Of Gains

CONTROL MODE PURPOSE ERROR DETECTIONS CONTROLS PG Reacts to Change Detects SIZE of Error

IG Reduces/Eliminates Offset Averages Error over TIME

DG Senses High Rate Load Detects RATE of change of error

 PG   IG   DG d (error )   CV (adjustable )   error * action     error dt * action     * action    bias  1000   1000   1000 dt  

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4. The difference between the setting at which 1. List advantages and disadvantages of a controller operates to one position and the pneumatic controls. setting at which it changes to the other is known as the: A) Throttling range B) Offset C) Differential D) Control point 2. Why is DDC so popular?

5. What is the flow rate of 16°C water through a control valve with a flow coefficient of 3. What does the term “direct acting” mean? 0.01 and a pressure difference of 100 kPa?

A) 0.1 LPS B) 0.2 LPS C) 0.6 LPS D) 0.4 LPS

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BUILDING BAS Anatomy Floor Level Network AUTOMATION Building Level Network SYSTEMS Management Level Network

(BAS) Remote System Access Remote Alarm Notification Interoperability with other Buildings/Systems/Networks

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RECOMMENDED GOAL FOR BASIC FUNCTIONS OPERATION OF NEW BAS’S 1. Monitoring/Surveillance  Single seat operation for the BAS using a common • Building Conditions database for all operational and maintenance data • Equipment Status accessible in the facility. • Utility Submetering  This means that the Maintenance Management • Climatic Data System and the Energy Management System(s) , at the • Fire & Security minimum, must share a common database. BUILDING 1A. General Service Meter 1B. Electric Heat Meter (Utility Meter for Billing) (Utility Meter for Billing)

5 7 8 9 10 2 3 4 Factory 6 1st 2nd Computer 11 Computer Facility Energy Factory Power Office Floor Floor Room Office Room HVAC Power Power and Power Office Office Power HVAC HVAC Lights Lights Lights and Lights

20 19 Factory 12 13 CAFE Lights Office Office RTU-1 RTU-13

14 15 Office Office RTU-3 RTU-4 24 Air Compressor

21 23 Energy 22 English Mezzanine Elevator Labs Test Room

16 17 18 Factory Factory Factory RTU RTU RTU

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BASIC FUNCTIONS START--SSTOP OPTIMIZATION

2. Demand Limiting  How It Works • Load shedding  Start the equipment at the latest possible time • Duty cycling  Stop at the earliest possible time ENERGY (KWH) 3. Maintenance SAVINGS FROM SSTO • Remote operation and control of equipment ENERGY (KWH) SAVINGS • Generation of maintenance schedules FROM SSTO • Diagnosing breakdowns 4. Record Generation • Trends and operation logs OCCUPANCY

DEMAND (KW) DEMAND PARTIAL • Utility demand profile (“baseline”) OCC • Modification/replacement analysis 0 2 4 6 8 10 12 14 16 18 20 22 24 • Energy conservation documentation OFF-PEAK PEAK OFF-PEAK $0.0453/KWH $0.0759/KWH $0.0453/KWH

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CHILLED WATER RESET CONDENSER WATER RESET  Introduction  Many buildings’ chilled water setting is designed for the  The same idea can be used on the other heaviest anticipated cooling load. side of the chiller by reducing the  Significant cost savings can result from resetting chilled water temperatures in anticipation of cooling load temperature of the cooling water from the  How It Works cooling tower.  When the load, chilled water T, or return chilled water  For everyyg one degree C reduction in the temperature increases, the chilled water setpoint is lowered, and vice versa temperature of the cooling water, the  A one degree C increase in CWT makes the chiller about 2% chiller efficiency goes up about 1.5 %. more efficient  Be careful with older chillers, since they  You must be able to meet both sensible and latent cooling loads. Also, there may be minimum flow condition on the can not take too cold cooling water without chiller that limits this change. developing head pressure problems.

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SUPPLY AIR RESET STATIC PRESSURE RESET  How It Works  Supply Air Reset Based on Load  The DDC system monitors the VAV static pressure and lowers the pressure until only one damper is completely open  A good rule of thumb provides for a supply air  The Static Pressure and VFD control sensors must be located on temperature reset for one-fourth the difference between the same DDC control panel the supply design temperature and the design space temperature  Savings Calculation  Lowest Desired Temp  Supply Air Design  SAR     Supply Air Design  4 

 Where: 40% 50% 60%

 Lowest Desired Temp is the temperature of the coolest room

 Supply Air Design is the current temperature of Supply Air

75% 100% 70%

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STATIC PRESSURE RESETS ECONOMIZER

• Proof of Performance • How It Works – Operating the fan with zero airflow wastes energy – Reduce cooling & heating energy by optimizing mixed air temp – As the outside air allows, the outdoor air damper opens more – Modulating fan speed based on damper position reduces fan usage and saves energy – Free heating/cooling occurs when occupant comfort is maintained without using mechanical heating or cooling

Economizer .g.) 2.5 Switch Point w 100 H e e 2.0 a r lv ti e a n p g V - m il No Reset C a o 1.5 o D C il r - V i g A n a r li lv o o e o o 1.0 Energy Savings td C % Open u O

0.5 MAM Reset Mechanical Heating Free Cooling Mechanical Cooling 0

Static Pressure (in. Static Pressure 0.0 0 50% 100% 5065 70 Demand Outside Air Temperature (ºF)

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DEMAND CONTROL VENTILATION HOT WATER RESET - HOW IT WORKS

 How It Works  Hot water boilers are very efficient at partial load  DCV provides just the right amount of outside needed by  Distribution losses are less when temperature is reduced occupants  Hot water reset conserves energy by reducing the boiler’s  Modulates ventilation to main target cfm/person operating temperature ventilation based on actual occupancy  Hot water reset reduces thermal shock because it does not  Less than 700 ppm above outside CO2 concentration involve drastic temperature fluctuations 100% r ity c o  To minimize flflueue gasgas corrosion, do not reset lower than 60 ºC 80%

60%

40%

Percent Building Occupancy 20% Percent Total Ventilation Capa

4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 24:00

Energy Cost with Occupancy Period Demand Controlled Ventilation

Building Occupancy/Demand Energy Savings with Ventilation Control Demand Controlled Ventilation

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HOT WATER RESET HOT WATER RESET

 Proof of Performance  Proof of Performance  Maintaining 180ºF (82 ºC)water temperature forces the  Resetting the hot water temperature allows heating heating valves to cycle open and closed valves to operate in more efficient mid-actuation positions

180 180 Hot Water Supply (ºF) 170 170 Theoretical Potential Savings 160 160

150 150 Hot Water Supply (ºF) 140 140

130 130

80 80

70 70 Valve Position (% open) Valve Position (% open) 60 60

50 50 40 40 30 30 Outside Air Temp (ºF) Outside Air Temp (ºF) 20 20

10 10 0 0 8:00 7:00 9:00 10:00 11:00 12:00 15:00 16:00 17:00 13:00 18:00 19:00 14:00 8:00 7:00 9:00 10:00 11:00 12:00 15:00 16:00 17:00 13:00 18:00 19:00 14:00

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REVIEW: REVIEW: BAS/EMS

1. Distinguish between analog and digital BAS control.

2. Devices using 4-20 mA current loops are using digital data transmission. (A) True (B) False

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5. An optimum start device is a control function that: 3. A facility is heated by fan coil units using (A) Shuts off the outside ventilation air during hot water pumped from a central boiler start up of the building. system. List some EMS controls that could reduce the facility energy costs. (B) Shuts off equipment for duty cycling purpose. (()C) Senses outdoor and indoor tem peratures to determine the minimum time needed to heat up or cool down a building. 4. List some maintenance aids that could be provided by an EMS. (D) Compares the enthalpy of outdoor and return air and determines the optimum mix of the two streams.

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Overall Recap

 Control Basics  Control Functions & Terminology  BAS/EMS Basics APPENDIX  BAS/EMS Functions & Programs

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CONTROL TERMINOLOGY  Differential – For a two-position controller it is the  Set Point – The value of the controlled variable difference between the setting at which the that is to be maintained. controller operates at one position and the setting at  Control Point - The actual value of the controlled which it changes to the other position. (All two- variable (temperature, pressure, flow, etc,). position controller need a differential to prevent “hunting,” or rapid cycling. For a thermostat, the differential is  Offset - The difference between the set point and the control point or the actual value of the expressed in degrees of temperature.) controlled variable. (This is sometimes called drift,  DeadDead--BandBand – The range over which the output of deviation,,pf or control point shift.) the controller remains constaconstantnt as the input varies,  Direct Acting Controller – A controller for which with the output changing only in response to an an increase in the level of the sensor signal input outside the differential range. (temperature, pressure, etc,) results in an increase in the level of the controller output.  Throttling Range – The amount of change in the controlled variable required to run the actuator of  Modulating Controller – A type of controller for which the output can vary infinitely over the range the controlled device from one end of its stroke to of the controller. the other end. (If the actual value of the controlled variable lies within the throttling range of the controller, it is said to be in control. When it exceeds the throttling range it is said to be out of control.)

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 Gain – The ratio of the output of the controller to WATER FLOW THROUGH VALVES the input. In a pneumatic temperature controller, for example, the gain would be expressed as:

gain = Controller Output (kPa) Throttling Range (degrees)

 Linear Percentage Valve – A valve with a plug shaped so that the flow varies directly with the lift.  Equal Percentage Valve –A valve with a plug shaped so the flow varies as the square root of the lift.

Flow (LPS) = Cv x √∆P

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OTHER EMS PROGRAMS 5. Warm Up/Cool Down Ventilation & Recirculation – Controls operation of the OA dampers when the introduction of OA would impose an 1. Scheduled Start/Stop – Starting and additional thermal load during warm-up or cool-down stopping equipment based upon the time of day, cycles prior to occupancy of a building. and the day of the week. 6. Hot Deck/Cold Deck Temperature Reset - Selects the zone/area with the greater heating and 2. Duty Cycling – Shutting down equipment for cooling requirements, and establishes the minimum hot and cold deck temperature differential which will meet predetermined short periods of time during the requirements. normal oppgerating hours. 7. Steam Boiler Optimization – Implemented in 3. Demand Limiting – Temporarily shedding heating plants with multiple boilers. Boiler plant optimization is accomplishes through the selection of the electrical loads to prevent exceeding a peak value. most efficient boiler to satisfy the space temperature 4. Unoccupied Setback – Lowering the space requirements during the building occupied period. heating setpoint or raising the space cooling 8. Reheat Coil/Reset – Selects the zone/area with the greatest need for reheat, and establishes the minimum setpoint during unoccupied hours. temperature of the heating hot water so that it is just hot enough to meet the reheat needs for that time period.

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9. Chiller &/or Boiler Optimization – For facilities with multiple chillers &/or boilers, the most efficient chiller(s) &/or boiler(s) are selected to meet the existing load with minimum demand and or energy. 10. Chiller Demand Limiting – The chiller electrical load is reduced at certain times to meet a maximum pre- specified chiller kW load. END OF SECTION V 11. Lighting Control – Turns lighting off and on according to a pre-set time sch ed ul e. 12. Remote Boiler Monitoring and Supervision – Uses sensors at the boiler to provide inputs to the EMCS for automatic central reporting of alarms, critical operating parameters, and remote shutdown of boilers. 13. Maintenance Management – Provides a maintenance schedule for utility plants, mechanical and electrical equipment based on run time, calendar time, or physical parameters.

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