Cooling Equipment
SNRG 154 – Building Systems
Sustainable Energy and Building Technology Program
Humber College – School of Applied Technology
Dragos Paraschiv, P.Eng.
dragos.paraschiv@humber.ca
Course Outline
Module 1: Introduction and terminology
Module 2: Thermal Comfort
Module 3: Indoor air quality
Module 4: Basics of Heat Loss/Gain and Equipment Sizing
Module 5: Wall and Roof Systems
Module 6: Moisture and Thermal Protection
Module 7: Doors and Windows
Mid Term
Module 8: Active climate controls
Module 9: Heating Equipment
Module 10: Cooling Equipment
Module 11: Air Handling Equipment and Systems
Module 12: Piping Equipment and Systems
Module 13: HVAC for Small Buildings
Module 14: HVAC for Large Buildings
Module 15: Plumbing Systems
Module 16: Fire Protection
Final Exam 2
Cooling Systems
Definition: Building Cooling System
A system that rejects heat (both sensible
and latent) from a space in order to
maintain temperatures at an
acceptable/comfortable level.
4
Classification of cooling systems
Distributed system: local AC units, each
with an integral refrigeration cycle
(equipment installed in or close to the
space served)
Central system: heat is rejected in a
common place (AC/furnace room in a
house; mechanical room in a large
building; central plant in a campus)
5
Distributed Systems - types
Window air conditioners
Through-the-wall room AC units
Air-cooled heat pump systems
Water-cooled heat pump system
6
Distributed Systems - advantages
Independent operation of each building
partition/zone
Pre-assembled units
Only one zone is affected by equipment
malfunction
System operation is simple
Initial cost is low
7
Distributed Systems - disadvantages
Typically lower system performance
Larger total building load (no diversity)
Comfort parameters may be less stable
Operating sound level may be high
Air filtration may be limited
8
Central Systems - applications
Campus environments
High-rise buildings
Large office buildings
Shopping malls
Hospitals
Industrial facilities
9
Central Systems - advantages
Lower operating cost due to less
equipment
Less occupant impact due to service
More energy efficient solutions
Multiple energy sources
Stand-by capabilities
Reduced total equipment capacity
Less vibration and noise problems
10
Central Systems - disadvantages
More complicated equipment
System controls may be complex
Special permitting may be required
First cost may be higher
Special requirements for operators
11
The Refrigerant cycle
12
The Refrigerant cycle (cont.)
13
Refrigerant cycle efficiency
Efficiency:
Output
eff .
Input
Coefficient of performance
Re frigeration _ Effect
COP 1
Heat _ of _ Compression
14
Heat pump or reverse cycle
Output
eff .
Input
Coefficient of performance
Re frigeration _ Effect Heat _ of _ Compression
COP 1
Heat _ of _ Compression
15
Cooling system types
Direct Expansion
o the evaporator is in direct contact with the air stream, so
the cooling coil of the airside loop is also the evaporator
of the refrigeration loop. The term “direct” refers to the
position of the evaporator with respect to the airside loop
o Air cooled or water cooled
Chilled water based system (Module 12)
o uses chilled water to transport heat energy between the
airside, chillers and the outdoors. These systems are
more commonly found in large HVAC installations, given
their efficiency advantages.
o Air cooled or water cooled
16
Direct expansion
17
Chilled water based system
18
Cooling Systems
Residential Buildings
Cooling and ventilation equipment
Central air conditioners
Room air conditioners
20
Central air conditioners
Single-package unit: contains all the components and
generally mounts through the wall or on the roof. Ducting
to and from the unit conveys air to and from the rooms.
This type is not commonly used in residential
applications
Split unit: consists of indoor and outdoor sections. The
indoor heat exchanger, or coil, mounts above the
furnace, inside the ducting. The outdoor section contains
the remaining components, and the two sections are
joined by refrigerant lines connecting the indoor coil to
the refrigeration components in the outdoor section
21
Central air conditioners (cont.)
Multi-split unit: split systems that contain more than one
indoor coil connected to one outdoor unit. They have
many indoor units. Because they do not require
ductwork, they are ideal for new additions to homes.
Small-duct high-velocity unit: distribute air through plastic
pipes in partition walls to outlets and inlets. These units
can be retrofitted in homes with electric or hydronic
baseboard heating that have no ductwork
Heat pumps
22
Central air conditioners (cont.)
Split-system
23
Central air conditioners (cont.)
Efficiency rating for Energy Star – Jan 1, 2009
Type SEER EER
Split system ≥14.5 ≥12.0
Single Package ≥14.0 ≥11.0
24
Room air conditioners
Window-mounted units: mounted into an open window
and plugged in
Through-the-wall units: tend to be less efficient than
regular window units
Portable units: have a hose that is used to exhaust heat
to the outside. Because they are on wheels, they can be
moved from room to room. Water condensed from the
cooled air has to be removed and drained away through
temporary ducting to the outdoors
25
Room air conditioners (cont.)
26
Cooling Systems
Larger Buildings
Hydronic cooling system schematic
28
Absorption refrigeration cycle
29
Absorption refrigeration cycle
30
Absorption refrigeration cycle
31
Absorption refrigeration cycle
32
Double effect absorption cycle
33
Hydronic cooling system with
heat recovery schematic
34
End of Module 10
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