Upload
antonio-buzbee
View
218
Download
0
Embed Size (px)
Citation preview
Foundations of Real Estate Management
BOMA International®
Module 3: Building Operations I
Heating, Ventilating, and Cooling the Building
®
Foundations of Real Estate ManagementModule 3: Building Operations I 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
Foundations of Real Estate ManagementModule 3: Building Operations I 3
®
Objectives
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 ManagementModule 3: Building Operations I 4
®
HVAC
Heating
Ventilating
Air Conditioning
Foundations of Real Estate ManagementModule 3: Building Operations I 5
®
Ventilation
Provides outside air
Removes stale air
Filters
Foundations of Real Estate ManagementModule 3: Building Operations I 6
®
Ventilation
Outside Air DamperPhoto courtesy of PM 101
Foundations of Real Estate ManagementModule 3: Building Operations I 7
®
Ventilation
Variable Frequency DrivePhoto courtesy of Transwestern
Foundations of Real Estate ManagementModule 3: Building Operations I 8
®
Ventilation
It’s a continuum
No outside air 100% outside air
Maximum energy efficiency Minimum energy efficiency
Minimum IAQ Maximum IAQ
Foundations of Real Estate ManagementModule 3: Building Operations I 9
®
Ventilation
Free cooling
Using outside air to condition the space
Foundations of Real Estate ManagementModule 3: Building Operations I 10
®
Ventilation
Exhaust
Removing odors and carbon dioxide
Foundations of Real Estate ManagementModule 3: Building Operations I 11
®
Ventilation
Separate exhaust for kitchens and
restrooms
Foundations of Real Estate ManagementModule 3: Building Operations I 12
®
Ventilation
Ensure restaurant tenants clean their exhaust system regularly
Foundations of Real Estate ManagementModule 3: Building Operations I 13
®
Ventilation
Plenum Return
Ducted Return
Foundations of Real Estate ManagementModule 3: Building Operations I 14
®
Ventilation
Partition Walls
Demising Walls
Fire Dampers
Protection
Foundations of Real Estate ManagementModule 3: Building Operations I 15
®
Ventilation
Photos courtesy of Transwestern
Foundations of Real Estate ManagementModule 3: Building Operations I 16
®
Humidity
ASHRAE recommends 50% relative humidity
(range of 30-60%)
Dehumidification
Humidification (rare)
Foundations of Real Estate ManagementModule 3: Building Operations I 17
®
Pressure
The Goal:
Pressure In = Pressure Out
Foundations of Real Estate ManagementModule 3: Building Operations I 18
®
Pressure
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 ManagementModule 3: Building Operations I 19
®
Pressure
Under Pressurization More air exhausted than brought in
Inoperable outside air fan, incorrect VFD settings
Front doors hard to open
HVAC becomes inefficient
Façade will leak
Foundations of Real Estate ManagementModule 3: Building Operations I 20
®
Filtration
Filters remove dust, debris, insects, and other contaminants
Pleated filters v. fiberglass filters
HEPA filters
Charcoal filters for odors
Changed routinely
Foundations of Real Estate ManagementModule 3: Building Operations I 21
®
Air Distribution
Air Handler
Trunk Line
Branch Line
VAV Boxes/Terminal Units
Supply Air Diffusers
Foundations of Real Estate ManagementModule 3: Building Operations I 22
®
Air Distribution - Zoning
Areas of the building operate differently from one another
Zones determined by:
Function/Use
Location
Foundations of Real Estate ManagementModule 3: Building Operations I 23
®
Air Distribution
Air Handling Unit (AHU) or Air Handler
Foundations of Real Estate ManagementModule 3: Building Operations I 24
®
Air Distribution
VAV Box – controlled by a thermostat
Foundations of Real Estate ManagementModule 3: Building Operations I 25
®
Air Distribution
Supply Air Diffuser
Foundations of Real Estate ManagementModule 3: Building Operations I 26
®
Air Distribution
Trunk and Branch Ducts
VAV Boxes and Supply Air Diffusers
Foundations of Real Estate ManagementModule 3: Building Operations I 27
®
Thermostat Types
Pneumatic
Direct Digital Control (DDC)
Set point temperature
Impossible to please everyone
Location
Foundations of Real Estate ManagementModule 3: Building Operations I 28
®
Thermostat
ASHRAE-recommended set points
71o F for heating (68-75o F)
76o F for cooling (73-79o F)
Balance tenant comfort with energy efficiency
Foundations of Real Estate ManagementModule 3: Building Operations I 29
®
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 ManagementModule 3: Building Operations I 31
®
Heating
Involves adding heat
Foundations of Real Estate ManagementModule 3: Building Operations I 32
®
Heating
Fuel Sources
Electricity
Natural Gas
Heating Oil
Foundations of Real Estate ManagementModule 3: Building Operations I 33
®
Heating
Systems
Central
Local
Foundations of Real Estate ManagementModule 3: Building Operations I 34
®
Heating
In most buildings, heating occurs only around perimeter – not in core
Air handler provides cooling to entire building
Electric heaters in perimeter VAV boxes heat perimeter as needed
Foundations of Real Estate ManagementModule 3: Building Operations I 35
®
Heating
Baseboard heating
Electric
Hot water or steam
Under floor or sidewalk (radiant)
Interlock
Foundations of Real Estate ManagementModule 3: Building Operations I 36
®
Cooling
Involves removing heat
Foundations of Real Estate ManagementModule 3: Building Operations I 37
®
Cooling
Just 3 Loops
Refrigerant Loop
Chilled Water Loop
Condenser Water Loop
The loops do not mix!
Foundations of Real Estate ManagementModule 3: Building Operations I 38
®
Cooling
The Refrigeration Loop/Cycle
Refrigerant
Compressor
Condenser
Expansion Valve
Foundations of Real Estate ManagementModule 3: Building Operations I 39
®
Cooling
Refrigerant
Fluid that absorbs heat
Moves from liquid to gas (add heat) and back to liquid (remove heat) easily
Boiling point is low: 50-60o F
Gas at room temperature
Foundations of Real Estate ManagementModule 3: Building Operations I 40
®
Cooling
Compressor
Applies pressure
Changes refrigerant from low pressure gas to a high pressure, super-heated vapor
Foundations of Real Estate ManagementModule 3: Building Operations I 41
®
Cooling
Condenser
Rejects heat outside building
Either air cooled or water cooled
Enters as a super-heated vapor
Leaves as a high temperature, high pressure liquid
Foundations of Real Estate ManagementModule 3: Building Operations I 42
®
Cooling
Expansion Valve
Sprays liquid into a fine mist
Reduces pressure and cools refrigerant
Foundations of Real Estate ManagementModule 3: Building Operations I 43
®
Cooling
Evaporator Transfers heat from building to refrigerant
Heating the refrigerant causes it to boil
Heated refrigerant then passes to compressor and the cycle continues…
Foundations of Real Estate ManagementModule 3: Building Operations I 44
®
Cooling
The refrigeration cycle is nothing more than changing the refrigerant from a liquid to a gas and back to
a liquid…over and over again
It’s a closed loop system
Foundations of Real Estate ManagementModule 3: Building Operations I 45
®
Cooling
The Refrigeration Cycle
Foundations of Real Estate ManagementModule 3: Building Operations I 46
®
Cooling
Heat always moves from
higher to lower
temperature
Foundations of Real Estate ManagementModule 3: Building Operations I 47
®
Coils and Bundles
Coils
Transfer heat between air and refrigerant
Bundles
Transfer heat between liquid and refrigerant
Foundations of Real Estate ManagementModule 3: Building Operations I 48
®
Coils and Bundles
Photo courtesy of PM 101
Coils
Foundations of Real Estate ManagementModule 3: Building Operations I 49
®
Coils and Bundles
Shell and Tube Bundles
Foundations of Real Estate ManagementModule 3: Building Operations I 50
®
Moving Heat from Inside to Outside
Chilled Water Loop
Rejects heat from occupied spaces to the refrigerant
Condenser Loop (air-cooled) or Condenser Water Loop (water-cooled)
Rejects heat from the refrigerant to outside of the building
Foundations of Real Estate ManagementModule 3: Building Operations I 51
®
Cooling
Chilled Water Loop
Water treatment is critical
Picks up heat in evaporator coil (in AHU) and takes heat to refrigerant loop
Cooler chilled water returns to evaporator coil to start process over again
As heat is removed, cooler air is blown through duct system by the AHU
Foundations of Real Estate ManagementModule 3: Building Operations I 52
®
Cooling
Condenser Water Loop (water-cooled)
Water treatment is critical
Picks up heat in refrigerant loop loop and takes heat to heat to cooling tower
Foundations of Real Estate ManagementModule 3: Building Operations I 53
®
Cooling
Cooling Tower
Condenser water pipes bathed in cool water sprayed inside cooling tower. Large fans also help transfer heat
Heat is transferred to outside
Cooler condenser water is pumped back inside to start cycle again
Foundations of Real Estate ManagementModule 3: Building Operations I 54
®
Cooling
Condenser Loop (air-cooled)
Air is blown over refrigerant loop to reject heat
Foundations of Real Estate ManagementModule 3: Building Operations I 55
®
Cooling
Water- or Air-Cooled Systems Chillers
Self-Contained Units (SCUs)
Air-Cooled Systems Rooftop Units (RTUs)
Split System
Heat Pump
Foundations of Real Estate ManagementModule 3: Building Operations I 56
®
Cooling
ChillerPhoto courtesy of PM 101
Foundations of Real Estate ManagementModule 3: Building Operations I 57
®
Cooling
Self-Contained Unit (SCU)Photos courtesy of PM 101
Foundations of Real Estate ManagementModule 3: Building Operations I 58
®
Cooling
Rooftop Unit (RTU)Photo courtesy of Thomas J. Easley
Foundations of Real Estate ManagementModule 3: Building Operations I 59
®
Cooling
Split SystemPhoto courtesy of Thomas J. Easley
Foundations of Real Estate ManagementModule 3: Building Operations I 61
®
Piped Systems
Types
2 Pipe
4 Pipe
Fan coil units
Foundations of Real Estate ManagementModule 3: Building Operations I 62
®
Free Cooling
Rejecting heat without using the compressor
Flat plate heat exchanger
Photo courtesy of Transwestern
Foundations of Real Estate ManagementModule 3: Building Operations I 63
®
Control Systems
Building Automation System (BAS)
Energy Management System (EMS)