Why "600 square feet per ton" gets so many Toronto homes wrong

Tonnage charts assume every house is built the same way, and no two Toronto houses are. A 1950s North York bungalow with plaster walls and small windows loses and gains heat very differently than a 2000s Vaughan two-storey with an open-concept great room and floor-to-ceiling glass. Insulation levels, window count and orientation, ceiling height, attic condition, and even the colour of the roof all change the actual cooling load — sometimes by a full ton in either direction from what a square-footage guess would suggest.

That is why we run a proper load calculation rather than quoting off square footage alone. It accounts for the building envelope, window area and exposure (that west-facing living room gets brutal afternoon sun in July), occupancy, and the condition of existing ductwork. The output is a real BTU/h cooling load, which then maps to a correctly sized system from our air conditioner buying guide and install line — not a guess rounded up "to be safe."

Rounding up is the mistake that causes the most comfort complaints. An oversized AC cools the air fast enough to satisfy the thermostat before it has run long enough to pull humidity out of the house, so the room feels cold and clammy at the same time. It also short-cycles, which wears the compressor faster than a correctly sized unit running full, steady cycles. If you are buying a home, replacing an aging system, or just tired of an oversized unit that never dehumidifies properly, this is the guide to work through before you get quotes.

Toronto and GTA conditions are not mild-climate marketing charts. Design temperatures, humidity, older building stock, and mixed fuel strategies change how AC Sizing Guide should be specified. We start with how you use the space — occupancy, hours, duct capacity, electrical service, and existing equipment — before recommending parts or a full replacement.

Homeowners, landlords, and facility managers call us when systems short-cycle, ice up, leave rooms uneven, spike utility bills, or fail on the first deep freeze or heat wave. Whether you need a same-week repair or a planned upgrade, we document findings and present repair-versus-replace paths with pricing you can compare.

Explore related hubs for heating, cooling, and commercial HVAC, or ask about rebates and incentives that may apply to high-efficiency equipment. Call 647 953-4252 with model numbers and symptoms so we arrive prepared.