Free tool
Furnace and AC size calculator
A quick bracket for the furnace and air conditioner size a Hamilton-area house needs, from its floor area and how well it holds heat.
Questions people ask
Why not just replace the furnace with the same size?
Many older furnaces were oversized to begin with, and windows, insulation and air sealing done since then lower the heat loss further. An oversized furnace or AC turns on and off in short bursts, wears faster, makes rooms uneven and, for AC, removes less humidity.
What is a CSA F280 calculation?
The Canadian standard for working out a house’s heat loss and heat gain room by room, using its walls, windows, insulation and air leakage. The Ontario Building Code requires it for a new heating or cooling system in a new house, and a good contractor does one for replacements too.
How many square feet does one ton of air conditioning cover?
In southern Ontario, roughly 500 to 750 square feet of above-grade floor area per ton, depending on the age of the house, its windows and its sun exposure. Basements usually need little cooling and are left out.
Hamilton · Burlington · Haldimand · Brant
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