from Sharon in Keshena, WI:
#292
How do you verify HVAC correct sizing for a home?
Sizing should be according to the home’s heat gain and loss.
The heating or cooling equipment should be sized according to the home's heat gain and loss (the amount of heat entering or exiting your home). Homeowners should insist that contractors use a correct sizing calculation before signing a contract. Key factors for correctly sizing a heating and cooling system include the following:
- The local climate
- Size, shape, and orientation of the house
- Insulation levels
- Window area, location, and type
- Air infiltration rates
- The number and ages of occupants
- Occupant comfort preferences
- The types and efficiencies of lights and major home appliances (which give off heat).
ACCA (Air Conditioner Contractors of America) offers Manual J, the HVAC industry's most accepted way to calculate a home's heat gains and losses. Manual J uses a number of factors, including wall area, window area, insulation values and exposure to determine the heating and cooling needs of a home. If you are getting different equipment sizes on your bids from contractors, talk to them and ask how the equipment size was determined.
Published Friday, June 19, 2009