Canada · CSA F280-12 methodology

CSA F280 heat loss calculator for Canadian homes.

Type the postal code, punch in the envelope, hit calculate. You get an F280-based heating and cooling load with real design temperatures for that town, plus a client-ready PDF, before you’re back in the truck. Metric first, English and French, fully offline.

iPhone & iPad
English + Français
Metric first
Works offline

Take F280 offline. NRCan climate tables travel with the app — no signal required.

Who it’s for

For the contractor quoting furnace swaps and heat pump retrofits.

Canadian residential HVAC contractors sizing replacements, AC adds, and cold-climate heat pumps. If you’re still working off square footage and a gut feel, this CSA F280 heat loss calculator replaces that. It’s the Canadian sibling of our US Manual J app, rebuilt around Canadian standards and Canadian weather — an honest country build, not an international mode.

Postal code in, design conditions out. Three characters of your postal code pulls heating and cooling design temperatures from NRCan HOT2000 data. 403 weather stations, 1,651 postal areas, all 13 provinces and territories.
Built on CSA F280-12 methodology. Envelope losses, air leakage, CSA F326 continuous ventilation with HRV and ERV credit, and internal gains, computed in watts. Planning estimates for quoting, not a stamped compliance document.
Basements done right. Below-grade walls and slabs lose heat to the deep earth, not the January air. The app models that depth-dependent loss, which is often a big slice of the load in a Canadian home.
Cold-climate heat pumps. It finds the balance point where falling capacity meets the house’s heat loss, and tells you how much backup heat the design day needs.
Real northern sun angles. Solar gain is figured by window direction up to 70 degrees north, so a Yellowknife job isn’t modelled like it’s in Ohio.
A PDF the homeowner can hold. Your logo, tagged site photos from the walkthrough, the load breakdown, and the recommended equipment size. Share it from the driveway.
English and French. Full French-Canadian localization reviewed by a Quebec native speaker, right down to “entretoit.”
Metric first, imperial when you want it. Two calculation modes today, Quick and Moderate, with a Pro tier coming. Projects sync between iPhone and iPad over iCloud.

In the field

Metric loads, Canadian climate data, scanned on site.

New project screen with the Simple, Moderate, and Pro mode selector, 13 of 13 fields ready, and floor area entered in square metres — Metric inputs by default. Moderate mode takes 15.

Calculation results for a Yellowknife postal code showing a 3.65 kW cooling load, a 15.45 kW heating load, a 5.28 kW AC size, a 17.58 kW furnace size, and a cooling breakdown by component — Loads in kW, with every component line shown.

LiDAR room scan in progress, with the app tracing glowing outlines along the walls, ceiling, and door frame of a room — Scan a room instead of typing its dimensions.

The numbers behind the numbers

Canadian data, named sources.

Methodology: CSA F280-12, Canada’s residential heat loss and gain standard. ACCA Manual J 8th Edition is also selectable per project.
Ventilation: continuous rate per CSA F326, driven by bedroom count, with sensible-recovery credit for HRV and ERV units.
Climate data: NRCan HOT2000 dataset under the Open Government Licence: 2.5 percent January heating dry-bulb, July 2.5 percent cooling dry-bulb with coincident wet-bulb, and HDD18 for every mapped postal area.
Pro-grade inputs: blower door CFM50 override, per-project window U-factor override, and heat pump balance point settings.
Honest scope: results are planning estimates. Final sizing should be verified by a licensed HVAC professional, and the app says so on every report.

Common questions

CSA F280 heat loss calculator FAQ

What is a CSA F280 heat loss calculation?

CSA F280 is Canada’s method for estimating residential heating and cooling loads. It accounts for the building envelope, air leakage, ventilation, internal gains, and Canadian design conditions — including below-grade losses that matter in Canadian winters.

Where do the Canadian design temperatures come from?

The bundled climate data is sourced from NRCan HOT2000 weather data and mapped by the first three characters of the postal code across all provinces and territories — 403 weather stations and 1,651 postal areas.

Is this CSA certified or a compliance document?

No. Results are planning estimates for qualified HVAC professionals based on CSA F280-12 methodology. The app is not CSA certified or approved for code compliance, and it is not a substitute for a stamped load calculation where one is required.

Does the CSA F280 heat loss calculator work offline?

Yes. Postal-area climate data and F280 calculation methods ship inside the app, so you can finish a calc in a mechanical room or a new build with no service.

Is the app available in French?

Yes. Full French-Canadian localization is included, reviewed by a Quebec native speaker.

Need US Manual J instead?

Use HVAC Load Calculator for ACCA Manual J 8th Edition methods with US ZIP climate data. This Canada app is rebuilt around CSA F280-12, not an international mode of the US product.

Get it offline

Winnipeg in January is not a rule-of-thumb town.

Install the CSA F280 heat loss calculator once. Finish the calc when cellular is gone — design temperatures and F280 methods stay on the phone.

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