3.3 hvac
TRANSCRIPT
Heating, Ventilating, and Air-Conditioning
TABLE OF CONTENTS• Types of Systems• Central Forced Air System
– Air Handling Unit• Hot Water System• Zoned Control System• Radiant Heat• Heat Pump• HVAC Plans
Types of Systems
• Central Forced-Air Systems• Hot Water Systems• Zone Control Systems• Radiant Heat
Central Forced Air System
• Most Common HVAC System• Circulates air through or around heating
and cooling devices.• A fan forces air into ducts• Supply ducts transport conditioned air into
building through diffusers or supply registers
• Air is routed back to heating/cooling device through return ducts
Air Handling Unit (AHU)
• Device used to condition and circulate air as part of an HVAC system
• Large metal box containing a blower, heating or cooling elements, filter, and sound attenuators
• Connects to ductwork that distributes the conditioned air through the building and returns it to the AHU
Courtesy Eric Fisher
Air Handling Unit (AHU)
• May need to supply heating, cooling, or both• A furnace generates heat
– Fuel oil or natural gas– Electric heating elements– Heat pump
• A refrigeration system absorbs heat– Air conditioner– Heat pump
Air Handling Unit (AHU)• Smaller air handlers may contain a fuel-burning
heater or a refrigeration evaporator placed directly in the air stream
• Large commercial air handling units contain coils that circulate water– Boiler provides hot water or steam– Chiller provides chilled water
©iStockphoto.com ©iStockphoto.com
Wikimedia
1. Supply duct2. Fan compartment3. Flexible connection4. Heating and/or cooling coil5. Filter compartment6. Return and fresh air duct
Typical AHU components:
Air Handling Unit (AHU)
Hot Water System
• Water heated in boiler and circulated through pipes to radiators
• Requires plumbing rather than ductwork
©iStockphoto.com
Zone Control System
• One heater and one thermostat per room• No ductwork• Often used in hotel rooms
Radiant Heat• Supply heat directly to the floor, wall, or ceiling• Hot water pipes or electric heating element runs
through building component• Dependent on radiant heat
– Heat transferred from hot surface to people and objects
Wikimedia
Heat Pump (HP)• A machine or device that moves heat from one
location (the source) to another location (the mechanical work)
• Can produce heating or cooling by reversing the direction of heat flow
• Can be used in:– Forced Air System– Hot Water System– Radiant Heat System
wikimedia
HVAC Plans
Image Courtesy Novus Architects
HVAC (Mechanical) Plans
Image Courtesy Novus Architects
HVAC Mechanical Plans
Image Courtesy Novus Architects
TABLE OF CONTENTS• Types of Systems• Central Forced Air System
– Air Handling Unit• Hot Water System• Zoned Control System• Radiant Heat• Heat Pump• HVAC Plans
•en.wikimedia.org. Images retrieved Dec. 8, 2009.•Novus Architecture (formerly SGM Architects), Mt.
Pleasant, SC•www.istockphoto.com. Images retrieved Dec. 8, 2009.
Image Sources
Heating, Ventilating, and Air-Conditioning