Foundations of Real Estate Management TM BOMA International ® Module 3: Building Operations I Heating, Ventilating, and Cooling the Building

Foundations of Real Estate Management Module 3: Building Operations I TM 2 Objectives  List the three components of the HVAC system  List the three tasks of the ventilation system  Explain why it is important to balance outside air and exhaust air pressures, and tell what happens in a commercial building if the pressures are uneven  Trace the flow of air through the duct work distribution system  Describe how electric reheat coils in a VAV box provide heat  Describe how baseboard heating systems provide heat  Describe the refrigeration cycle  Describe the chilled water cycle  Describe the condenser water cycle  List at least five methods to improve efficiency of heating and cooling functions

Foundations of Real Estate Management Module 3: Building Operations I TM 3 HVAC Heating Ventilating Air Conditioning

Foundations of Real Estate Management Module 3: Building Operations I TM 4 Ventilation System  Provides outside air  Removes stale air  Filtration

Foundations of Real Estate Management Module 3: Building Operations I TM 5 Variable Frequency Drive (VFD)  Used to regulate speed of pumps/motors  Reduces energy costs  Improves efficiency

Foundations of Real Estate Management Module 3: Building Operations I TM 6 Ventilation System It’s a continuum – building settings are somewhere in the middle No outside air 100% outside air Maximum energy efficiency Minimum energy efficiency Minimum IAQ Maximum IAQ

Foundations of Real Estate Management Module 3: Building Operations I TM 7 Energy Savings  Free Cooling  Using outside air to condition the space without mechanical cooling  Many types of free cooling options  Depends upon HVAC system design

Foundations of Real Estate Management Module 3: Building Operations I TM 8 Exhaust System  Removes odors and carbon dioxide (CO 2 )  Separate exhaust system for kitchens and restrooms  Restaurant/commercial kitchen exhaust systems need to be cleaned regularly

Foundations of Real Estate Management Module 3: Building Operations I TM 9 Humidity  ASHRAE recommends 50% relative humidity (range of 30-60%) in commercial buildings  Dehumidification  Humidification

Foundations of Real Estate Management Module 3: Building Operations I TM 10 Air Moves in a Circle  Supply  Return  Plenum return  Ducted return

Foundations of Real Estate Management Module 3: Building Operations I TM 11 Walls Can Impact HVAC  Partition walls  Floor slab to ceiling  Demising walls  Floor slab to deck  Principal purpose  Fire protection  Impact plenum return  Fire dampers

Foundations of Real Estate Management Module 3: Building Operations I TM 12 Pressure

Foundations of Real Estate Management Module 3: Building Operations I TM 13 Over Pressurization  More air is brought in than is exhausted  Inoperable exhaust fan  Incorrect VFD settings  Front doors will not close properly  People feel pressure (like on airplane)  HVAC becomes inefficient

Foundations of Real Estate Management Module 3: Building Operations I TM 14 Under Pressurization  More air exhausted than brought in  Inoperable outside air fan  Incorrect VFD settings  Front doors hard to open  HVAC becomes inefficient  Roof and façade will leak

Foundations of Real Estate Management Module 3: Building Operations I TM 15 Filtration  Filters remove dust, debris, insects, and other contaminants  Pleated filters v. fiberglass filters  Changed routinely

Foundations of Real Estate Management Module 3: Building Operations I TM 16 Air Distribution  Air handler  Fan  Ductwork  Trunk line  Branch line  VAV boxes/terminal units  Temperature/air flow regulation  Controlled by thermostat  Supply air diffusers  Distribute air in space

Foundations of Real Estate Management Module 3: Building Operations I TM 17 Air Distribution - Zoning  Areas of building operate differently from one another  Zones determined by  Function/use  Location  Heat sources  External  Internal

Foundations of Real Estate Management Module 3: Building Operations I TM 18 Thermostat  Usually, each zone has a thermostat  Set point temperature  Impossible to please everyone  ASHRAE recommends  71 o F for heating (68-75 o F)  76 o F for cooling (73-79 o F)  Location  Balance tenant comfort with energy efficiency

Foundations of Real Estate Management Module 3: Building Operations I TM 19 Thermal Layering Temperature is measured in the middle 1/3 (on top of the desk) Bottom 1/3 is coolest (space heaters) Heat rises – top 1/3 is warmest

Foundations of Real Estate Management Module 3: Building Operations I TM 20 Space Heaters

Foundations of Real Estate Management Module 3: Building Operations I TM 21 Heating Involves adding heat

Foundations of Real Estate Management Module 3: Building Operations I TM 22 Heating  Systems  Central  Local  Fuel sources  Electricity  Natural gas  Heating oil

Foundations of Real Estate Management Module 3: Building Operations I TM 23 Heating  Heating only around perimeter – not in core  Air handler provides cooling to entire building  Common perimeter heating systems  Electric heaters in perimeter VAV boxes  Baseboard heat  2-pipe/4-pipe central heating  Radiant heat  Under concrete sidewalks and drive lanes  Under floor

Foundations of Real Estate Management Module 3: Building Operations I TM 24 VAV Box with Reheat Coils

Foundations of Real Estate Management Module 3: Building Operations I TM 25 Cooling Involves removing heat

Foundations of Real Estate Management Module 3: Building Operations I TM 26 Cooling  HVAC systems have 1, 2, or 3 loops  Refrigerant loop  Chilled water loop  Condenser water loop  The loops do not mix!

Foundations of Real Estate Management Module 3: Building Operations I TM 27 Cooling  Refrigeration cycle  Refrigerant  Compressor  Condenser  Expansion valve  Evaporator

Foundations of Real Estate Management Module 3: Building Operations I TM 28 Refrigerant  Makes air conditioning and refrigeration possible  Absorbs heat efficiently  Moves from liquid to gas (add heat) and back to liquid (remove heat) easily  Low boiling point: o F  Gas at room temperature

Foundations of Real Estate Management Module 3: Building Operations I TM 29 Refrigeration Cycle

Foundations of Real Estate Management Module 3: Building Operations I TM 30 Refrigeration Cycle

Foundations of Real Estate Management Module 3: Building Operations I TM 31 Refrigeration Cycle

Foundations of Real Estate Management Module 3: Building Operations I TM 32 Compressor  Applies pressure  Changes refrigerant from low pressure gas to a high pressure, super- heated vapor

Foundations of Real Estate Management Module 3: Building Operations I TM 33 Condenser  Rejects heat outside  Air or water cooled cooled  Enters as super-heated vapor  Leaves as high temperature, high pressure liquid

Foundations of Real Estate Management Module 3: Building Operations I TM 34 Expansion Valve  Sprays liquid into fine mist  Reduces pressure and cools refrigerant

Foundations of Real Estate Management Module 3: Building Operations I TM 35 Evaporator  Transfers heat from building to refrigerant  Heating refrigerant causes it to boil  Heated refrigerant then passes to compressor… and the cycle continues

Foundations of Real Estate Management Module 3: Building Operations I TM 36 Closed Loop System The refrigeration cycle is nothing more than changing refrigerant from a liquid to a gas and back to a liquid…over and over again It’s a closed loop system Heat always moves from higher to lower temperature

Foundations of Real Estate Management Module 3: Building Operations I TM 37 Single Loop System  Refrigeration cycle only  Air cooled  Condenser loop  To condenser outside  Air blows against coils to reject heat  Like your home air conditioner  Split system  Heat pump  Rooftop unit

Foundations of Real Estate Management Module 3: Building Operations I TM 38 Coils

Foundations of Real Estate Management Module 3: Building Operations I TM 39 Double Loop System  Heat transferred to/from refrigerant using water via bundles  System has either  Condenser water loop  From refrigeration loop to cooling tower  Chilled water loop  From tenant space to refrigeration loop

Foundations of Real Estate Management Module 3: Building Operations I TM 40 Triple Loop System  Heat transferred to/from refrigerant using water via bundles  System has both  Condenser water loop  From refrigeration loop to cooling tower  Chilled water loop  From tenant space to refrigeration loop

Foundations of Real Estate Management Module 3: Building Operations I TM 41 Cooling Tower  Hot condenser water enters top of cooling tower  Large fans help transfer heat  Heat is transferred to outside air  Cooler condenser water is pumped back inside to start cycle again

Foundations of Real Estate Management Module 3: Building Operations I TM 42 Typical Commercial Cooling Systems  Water- or Air-Cooled Systems  Chillers  Self-Contained Units (SCUs)  Air-Cooled Systems  Rooftop Units (RTUs)  Split System  Heat Pump

Foundations of Real Estate Management Module 3: Building Operations I TM 43 Chiller

Foundations of Real Estate Management Module 3: Building Operations I TM 44 Self-Contained Unit (SCU)

Foundations of Real Estate Management Module 3: Building Operations I TM 45 Rooftop Unit (RTU)

Foundations of Real Estate Management Module 3: Building Operations I TM 46 Split System

Foundations of Real Estate Management Module 3: Building Operations I TM 47 Heat Pump

Foundations of Real Estate Management Module 3: Building Operations I TM 48 Control Systems  Building Automation System (BAS)  Energy Management System (EMS)

Foundations of Real Estate Management Module 3: Building Operations I TM 49 Controlling HVAC Costs  Optimize EMS  Use free cooling  Pay attention to weather  Coasting  Control tenant HVAC adjustments  Aggressive water treatment  Keep all components clean