AC Size & Tonnage - Burlington Heating And Cooling

AC Size & Tonnage Calculator Burlington, ON

Proper sizing is the single most overlooked factor in AC performance.
Find the right tonnage for your Burlington home — not too big, not too small.

📐 Ontario Climate Data

⚡ Instant Result

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Home Size (sq ft)	Starting Estimate	BTU/h Range
700 – 1,000	1.5 tonnes	18,000 BTU/h
1,000 – 1,400	1.5 – 2 tonnes	18,000 – 24,000 BTU/h
1,400 – 1,900	2 – 2.5 tonnes	24,000 – 30,000 BTU/h
1,900 – 2,500	2.5 – 3 tonnes	30,000 – 36,000 BTU/h
2,500 – 3,200	3 – 3.5 tonnes	36,000 – 42,000 BTU/h
3,200 – 4,200	3.5 – 5 tonnes	42,000 – 60,000 BTU/h

*Estimates for average Burlington home construction. Older homes, high ceilings, or large south/west-facing windows may need additional capacity.

Why Oversizing Is a Real Problem in Burlington

Burlington summers are humid. That matters enormously for AC sizing. An oversized AC reaches your thermostat's set temperature quickly — but it doesn't run long enough to pull moisture out of the air. The result is a home that reads 22°C on the thermostat but feels clammy and uncomfortable. Dehumidification requires sustained run time, which only a properly sized system delivers. This is one reason why manual J load calculations exist rather than simple square-footage rules.

On top of comfort, oversizing shortens equipment lifespan. Short-cycling — frequent start-stop cycles — strains the compressor and accelerates wear. A 3-tonne AC that short-cycles in a 1,600 sq ft home may need replacement years earlier than a correctly sized 2-tonne unit would.

📏 Square Footage

The starting point — but measure only the conditioned (cooled) living space. Don't include uncooled garages or unfinished basements.

🌡️ Burlington's Climate

Summer design temp: ~31°C. Humidity adds effective cooling load beyond what dry-bulb temperature alone suggests. Burlington's lake proximity offers some relief but not on peak heat days.

🏗️ Insulation & Age

Homes built before 1990 often have R-12 or lower wall insulation. Upgrading to R-20+ can reduce cooling load by 20–25%, meaningfully shifting your tonnage requirement.

🪟 Windows & Orientation

West-facing windows take the full force of afternoon sun. A Burlington semi-detached with large west-facing windows may need 0.5 tonnes more than the same floorplan facing north.

📐 Ceiling Height

Standard 8-foot ceilings are the baseline. Vaulted or 10-foot ceilings increase the air volume that needs cooling — push toward the upper end of the range.

👥 Occupancy & Appliances

Each person adds ~250 BTU/h of heat load. Open-concept kitchens, home offices with multiple computers, and home gyms all increase the effective cooling requirement.

Burlington vs. Other Ontario Cities — Sizing Impact

Burlington's location near Lake Ontario places it in a moderate position compared to other southern Ontario cities. Windsor and London tend to be hotter; Ottawa spikes higher but also has colder winters. Here's how Burlington compares for sizing purposes.

City	Summer Design Temp (°C)	Sizing vs. Burlington
Windsor, ON	33°C	+12% larger needed
London, ON	32°C	+8% larger needed
Toronto, ON	31°C	Similar to Burlington
Burlington, ON	31°C	— Baseline —
Hamilton, ON	31°C	Similar to Burlington
Ottawa, ON	30°C	~4% smaller possible

Frequently Asked Questions

My neighbour has a 3-tonne AC in the same size house. Should I get the same?

Not necessarily. If your homes face different directions, have different window sizes, or were insulated to different standards, their cooling load may differ meaningfully. That said, if your homes are nearly identical builds (same subdivision era, same floor plan, similar window configuration), their contractor's sizing is a useful data point — just not a substitute for a proper calculation for your specific home.

What is a Manual J calculation and do I need one?

Manual J is the industry-standard heat load calculation method, developed by ACCA. A qualified HVAC technician uses your home's dimensions, insulation values, window specs, and local design temperatures to determine exact cooling load. You don't have to pay for it separately — reputable Burlington contractors typically perform a simplified Manual J calculation as part of their quoting process. Be cautious of any contractor who quotes a size without asking about your home's construction details.

Can I just replace my existing AC with the same tonnage?

Usually yes — if your current system has been comfortable and properly sized. But if your home was originally installed with an oversized unit (common in homes built in the 1990s), matching the old tonnage perpetuates the problem. If you've ever had the AC run constantly without reaching temperature in summer, undersizing is the issue. If it never runs long and the house feels humid, oversizing is likely the culprit.