Facilities Management and Design
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Transcript Facilities Management and Design
Facilities Management and Design
Chapter 7
HVAC Systems
Thermal Comfort
Balancing heat produced by one’s body with
surrounding environment.
Body heat lost by convection, radiation, and
evaporation
Factors that influence comfort
indoor temperature
humidity
air movement
room surface temperatures
overall air quality
Comfort zone
Insert comfort zone chart
Heat sources
Electricity– Used in all electric heaters. Requires no
flue. Usually most expensive.
Natural gas – Clean burning. Flue required. Very
efficient. Delivered via underground pipe
Liquefied petroleum – relatively clean burning. Requires
on-site storage tank. Delivered via truck.
Fuel oil – tendency to create dirt/smoke. Requires onsite storage tank. Delivered via truck. Various grades
available.
Steam – more common in urban areas where available
from local utility or in large complexes with central
steam plant. Supply and return lines required.
Heating equipment
Furnaces and Boilers
Combustion efficiency
Flue
Furnace
Heat
Exchanger
Cooling Systems
Boyles Ideal Gas Law
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Pressure
Temperature
Volume
Certain gases react more
actively
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Refrigerants
CFC’s
HCFC’s
The Refrigeration Cycle
Compressor
Evaporator Coil
Condenser Coil
Expansion Valve/ Metering Device
Cooling system operating and
maintenance concerns
Types of compressors
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Reciprocating
Centrifugal
Rotary
Energy efficiency ratio (EER)
Integrated part load values (IPLV)
Environmental Protection Agency
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supervises aspects of refrigeration equipment maintenance
importance of eliminating or reducing refrigerant leaks
Cooling system operating and
maintenance concerns
Types of compressors
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Reciprocating
Centrifugal
Rotary
Energy efficiency ratio (EER)
Integrated part load values (IPLV)
Environmental Protection Agency
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supervises aspects of refrigeration equipment maintenance
importance of eliminating or reducing refrigerant leaks
HVAC system types
Centralized systems; quiet
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Decentralized systems; not as quiet
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two-pipe
three-pipe
four-pipe
heating and cooling sources in guestroom itself or along
outside wall
Hybrid systems
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characteristics of centralized and decentralized systems
System types and maintenance needs of
HVAC systems for other building areas
Air handling units
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Packaged air conditioning units
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Isolation of zones (housekeeping, kitchen, maintenance…)
usually mounted on roof
Maintenance issues
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Filter replacement
belt checking and replacement
cleaning of fans and heat transfer surfaces
HVAC controls
Today’s controls are often electronic
Thermostat
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enthalpy or economizer control
Older control sensors—mechanical sensing
Digital control systems
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variable air volume (VAV) systems
load sensing equipment
EMS sensors
Cooling towers
Startup and shutdown concerns
Inspection and lubrication of pumps and fans
Removal of dirt and other debris
Treatments to reduce bacteria, scale, and
corrosion
Inspection of metal surfaces