Air conditioner size is measured in tons — one ton equals 12,000 BTU of cooling per hour. A rough starting point for a GTA home is about one ton per 500–600 square feet, but that's only a ballpark. The real number comes from a load calculation, because the right size depends on far more than floor area.
Why bigger is not better
It's tempting to think a larger AC cools better. It doesn't. An oversized unit blasts the air cold fast, hits the thermostat target, and shuts off — before it has run long enough to pull humidity out of the air. The result is a house that feels cold and clammy, plus more wear from constant short-cycling. An undersized unit has the opposite problem: it runs flat-out and never quite catches up on the hottest days. Right-sizing matters more for cooling than for heating.
What actually decides the size
- Square footage, layout, and ceiling height
- Insulation and how well the home is sealed
- Windows — how many, how big, and which way they face (west- and south-facing glass adds a big cooling load)
- Sun exposure and shade
- How many people live there, and heat-producing appliances
- Our climate — humid GTA summers change the math
How we size it
We don't round up to be safe. We look at your home — its size, insulation, windows, and exposure — and size the unit to match, so it runs long enough to dehumidify without short-cycling. If you're also weighing a heat pump (which cools exactly like an AC and heats too), the same careful sizing applies, with the winter heating load factored in. Either way, you get a written recommendation and price after we see the home, not a guess over the phone.
Want a straight answer for your home?
We give you a written price before any work starts — the estimate is free and there's no obligation.
Questions, answered
What size air conditioner do I need for my house?
A rough starting point is about one ton (12,000 BTU) per 500–600 square feet for a GTA home, but the right size comes from a load calculation that accounts for insulation, windows, sun exposure, and ceiling height — not square footage alone.
Is a bigger air conditioner better?
No. An oversized AC short-cycles — it cools fast and shuts off before removing humidity, leaving the house cold and clammy and wearing out faster. The right size runs long enough to dehumidify properly.
What happens if my AC is too small?
An undersized unit runs constantly and can't keep up on the hottest days, driving up wear and your bill while never quite cooling the home. That's why correct sizing matters.
How is AC size measured?
In tons — one ton equals 12,000 BTU of cooling per hour. Most GTA homes need somewhere between 1.5 and 5 tons, confirmed by a load calculation for your specific home.
