Installing the right size equipment for the home is essential to getting
the best performance and comfort. Many homeowners believe
that bigger is better when buying new heating and cooling equipment.
But in reality, a system that is too large will not keep your
home comfortable because of frequent on-off cycling. Incorrect
sizing also can put stress on system components and shorten the
To ensure proper sizing, your contractor should calculate your
home’s heating and cooling loads using ACCA’s Manual J or equivalent.
The contractor should provide a copy of the home’s heat gain/
loss calculations for your records.