CSA F280 vs Manual J: Which Heat Loss Method Applies in Alberta?
Both are room-by-room methods for working out how much heating and cooling a house needs. Manual J is published by ACCA, the Air Conditioning Contractors of America, and is the usual method in the United States. CSA F280-12 is the Canadian standard, and it is the one the building code in Alberta points to for sizing heating and cooling equipment in houses. For a house permit in Alberta, plan on an F280 calculation.
By the Ductscale design team. Reviewed by Raymond, founder and lead HVAC designer. Updated .
What the two methods have in common
F280 and Manual J start from the same idea: calculate the heat each room loses in winter and gains in summer, then size the equipment and ducts from those numbers instead of a rule of thumb. Both take in the same kinds of inputs:
- Wall, ceiling, floor and below-grade areas with their insulation values
- Window and door sizes, and the sun coming through the glass
- Air leakage and ventilation
- Indoor and outdoor design temperatures for the location
Where they differ
Who publishes it and where it applies. Manual J comes from ACCA in the United States. F280 comes from CSA Group and is referenced by Canadian building codes for houses.
Climate data. An F280 calculation uses the design temperatures from the Canadian building code for the home's location. Manual J uses ACCA's own design condition tables, which are built mainly around US locations.
Equipment selection. Manual J calculates the loads, and ACCA covers equipment selection in a separate manual, Manual S. F280 includes both: it calculates the loads and also sets limits on the output of the heating and cooling equipment you pick.
Which one your permit needs
In Alberta, the building code points to CSA F280-12 for sizing heating and cooling in houses (Part 9 buildings). The City of Calgary's mechanical permit checklist for geoexchange systems, for example, asks for a heat loss calculation to CSA F280 for Part 9 buildings and to ASHRAE methods for larger Part 3 buildings.
Each municipality sets the documents for its permits, so check the current checklist for your project. If a contractor gives you a Manual J report, ask whether it was done to F280 or whether the permit office will accept it before you rely on it.
Is F280-12 still the current edition?
Yes. CSA reaffirmed F280-12 in 2025, so the 2012 edition is still the one in use. Our reports are done to CSA F280-12.
FAQ
Common questions
Is Manual J accepted for house permits in Calgary?
The building code points to CSA F280 for houses, so an F280 calculation is the safe choice. If you already have a Manual J report, ask the permit office before relying on it.
Do F280 and Manual J give the same answer?
They often land close for the same house, but they use different climate data and assumptions, so the room-by-room numbers will not match exactly.
Can you convert a Manual J report to F280?
We run a new F280 calculation from the plans. The Manual J report helps as a cross-check, but the F280 report is built from its own inputs.