How many BTU for 3,000 sq ft?
Updated October 24, 2026
To heat 3,000 sq ft (279 m²) you need between 45,000 and 89,800 BTU/h depending on your city and insulation. Here is the calculation city by city, using the CSA F280 method.
Assumption: a 3,000 sq ft two-storey house with no heated basement, 8 ft ceilings, windows in proportion to floor area.
Heating load by city and house age
| City | After 2010 | 1990 to 2010 | 1970 to 1990 | Before 1970 | Cooling* |
|---|---|---|---|---|---|
| Vancouver (-7 °C) | 45,000 | 45,000 | 45,000 | 48,200 | 20,300 |
| Toronto (-18 °C) | 45,000 | 45,000 | 50,000 | 66,500 | 23,700 |
| Halifax (-16 °C) | 45,000 | 45,000 | 47,500 | 63,200 | 19,400 |
| Montreal (-23 °C) | 45,000 | 45,000 | 56,300 | 74,900 | 22,000 |
| Quebec City (-26 °C) | 45,000 | 45,000 | 60,000 | 79,900 | 20,300 |
| Winnipeg (-31 °C) | 45,000 | 45,700 | 66,300 | 88,200 | 22,000 |
| Edmonton (-32 °C) | 45,000 | 46,500 | 67,600 | 89,800 | 19,400 |
* Cooling for a 1990–2010 house, at the city’s summer design temperature.
Which Kanartic system for 3,000 sq ft?
Newer house in Toronto
Z-PRO 36,000 · 2 zones + ZERO 12,000 wall unitfrom $7,674 · DIY
Covers 100% of the heating load at -18 °C
See on kanartic.ca1990–2010 house in Montreal
Z-PRO 36,000 · 2 zones + ZERO 12,000 wall unitfrom $7,674 · DIY
Covers 100% of the heating load at -23 °C
See on kanartic.caPre-1970 house in Edmonton
Z-PRO 36,000 · 2 zones + ZERO 24,000 wall unitfrom $8,974 · DIY
Covers 67% of the heating load at -32 °C
See on kanartic.caWhat about 25 BTU per square foot?
The rule of thumb would give 75,000 BTU/h for 3,000 sq ft. The component calculation gives 45,000 to 89,800 BTU/h: depending on the house and climate, the rule is off by −16% to +67%.
Frequently asked questions
Is a 12,000 BTU heat pump enough for 3,000 sq ft?
In Montreal, for a 1990–2010 house, a 12,000 BTU unit covers 27% of the load at -23 °C; for a pre-1970 house, 16%. So you need a bigger unit or backup heat.
How many BTU to cool 3,000 sq ft?
Between 19,400 and 23,700 BTU/h for a 1990–2010 house, depending on the city. In Canada, heating sets heat pump size, not cooling.
Wall unit or multi-zone for 3,000 sq ft?
At this size, a multi-zone puts one indoor unit per floor or large room, connected to a single outdoor unit.
Other floor areas
2,400 sq ft2,600 sq ft2,800 sq ftAll
How many BTU for my house?Why not to oversizeHeat pump costBy room