HEATING AND COOLING SYSTEMS
HEATING SYSTEMS Fuel Types: Sun Natural gas Electricity High pressure city steam
HEATING SYSTEMS Sun Begin design with an assortment of solar heating possibilities
HEATING SYSTEMS Natural Gas Second most common fuel for heating
HEATING SYSTEMS Electricity Lowest installation cost More expensive than gas
HEATING SYSTEMS High Pressure City Steam By-product – exhaust steam generates electricity
HEATING SYSTEMS Gas – Fired Heaters Semi outdoor locations only Can be used inside for warehouses etc if vented
HEATING SYSTEMS Warm Air Heating First appeared in 1900 Oil, gas or electric Forced air – provisions for adding an outdoor compressor and condensing unit for cooling
HEATING SYSTEMS Warm Air Heating System burns gas, oil or heats electrical coils inside a closed chamber – heat exchanger – inside furnace Large blower inside the furnace compartment forces cool air across the hot outer surface of the heat exchanger – heating the air Fans move the heated air through a system of supply ducts located inside the walls and between floors and ceilings
HEATING SYSTEMS Warm Air Heating Supply registers – equipped with dampers – inside the ducts balance and adjust system by controlling airflow Damper vanes disperse air, controlling direction and velocity
HEATING SYSTEMS Warm Air Heating Separate system of exhaust ducts draws cool air back through the return grills to be reheated and re- circulated Return grills are generally located near the floor, on walls or the ceiling
COOLING SYSTEMS Mechanical cooling systems originally a separate unit to be used in conjunction with heating equipment Currently integrated into HVAC systems
COOLING SYSTEMS Cooling accounts for 20% of energy use in the U.S. 40% in the southern states
COOLING SYSTEMS Air Conditioning The treatment of air so that it’s temperature, humidity, cleanliness, quality and motion are maintained as appropriate for the building’s occupants, a particular process or some object in the space
COOLING SYSTEMS Design Strategies for Cooling: Relationship with the building form and day lighting decisions Number and location of openings Utilization of natural ventilation
COOLING SYSTEMS Process of Air Conditioning: Fan sucks warm air indoors across a series of coils containing refrigerants and blows it back into the room Refrigerant absorbs heat in the evaporator and then exhausts it outside through a system of fans and coils in the condenser When indoor air is cooled – also dehumidified
COOLING SYSTEMS Process of Air Conditioning
COOLING SYSTEMS Fans Used in small buildings Person perceives a decrease of 1 degree Fahrenheit for every 15 feet per minute increase in the speed of air past the body
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