The presets are approximate regional defaults. Replace them with the January 2.5% and July 2.5% dry-bulb values for the project location.
Room-by-Room Summary
Full Load Calculation Table
| Room | Floor Area | Heating Load | Cooling Load |
|---|
How to Build a Load Calculation Report
Add the project name and pick the nearest city preset, then adjust the winter and summer design temperatures to the exact project location and set the furnace efficiency (AFUE).
Enter the room name, floor area, and the heating and cooling load for each room from your load calculation. Leave a load blank if it was not calculated.
Add a row for every room until the entire building is accounted for in the load calculation.
Click Generate Load Report to produce the formatted document with totals and an equipment sizing recommendation, then export for the permit set.
Understanding Load Calculation Reports in Canada
A load calculation report turns raw numbers into something a permit reviewer, a client, or an installing technician can actually use. The calculation itself matters, but so does the presentation: a room-by-room breakdown, clearly stated design conditions, and a sizing recommendation that follows logically from the numbers above it.
Why Design Temperatures Vary So Much Across Canada
Canada's climate zones are wide enough that a single national design temperature would be useless. The National Building Code's climatic data table lists January 2.5 percent, January 1 percent, and July 2.5 percent dry-bulb values by location, and the January 2.5 percent value is the one ordinarily used to design heating systems. Because most readings come from airports, the value for a city core can be a degree or two milder. The presets in this tool are approximate regional defaults and the fields stay editable, so replace them with the exact values for the project. The design temperature lookup is a quick way to find values by city, though the table your authority requires always governs. Using the correct regional design temperature isn't a minor detail, it's the foundation the entire heating load calculation rests on.
Why Both Heating and Cooling Loads Matter
Heating load is driven mostly by the building envelope and the winter design temperature. Cooling load adds solar gain through windows, occupant heat, and appliance loads on top of the envelope calculation, using the summer design temperature instead. Equipment has to handle both conditions well, so a load report that only shows one of the two numbers leaves the equipment selection only half informed. This tool takes both loads as inputs and does not estimate one from the other, because the ratio between them changes with glazing, orientation, and climate. If you need a room's cooling load first, the cooling load calculator works it out.
Matching Equipment to the Load, Not Oversizing
It's tempting to round up "for safety," but oversized equipment cycles on and off more frequently, which generally means worse humidity control and less even comfort, not more. The right approach is to match equipment as closely as possible to the calculated load, then round up only to the nearest standard capacity a manufacturer actually produces. For a furnace this tool divides the heating load by the furnace efficiency to get the input capacity needed, then picks the next standard input size, and it warns when the output of that size is more than 140 percent of the load, a limit commonly cited from ACCA Manual S. For air conditioning it rounds the cooling load up to the next standard size in tons.
What Permit Reviewers Look For
A reviewer checking a load calculation report typically wants to see the design conditions stated clearly, a room-by-room or zone-by-zone breakdown rather than just a building total, and a sizing conclusion that's consistent with the numbers shown. In Canadian housing the calculation behind those numbers is normally done to CSA F280, the standard for determining the required capacity of residential heating and cooling appliances. Pairing this report with the duct schedule generator in this category gives a reviewer the complete mechanical picture: what's producing the conditioned air and what's distributing it.
Confirming Local Requirements
Not every municipality wants the same format. Some authorities having jurisdiction have specific templates or software output requirements, and some projects now ask about future climate as well. ClimateData.ca explains how the code's climatic design values are being adjusted for a warming climate. Confirming expectations with the local building department before submission is a small step that avoids a rejected or delayed permit application over a formatting issue rather than a substantive one.
Frequently Asked Questions
Use the January 2.5 percent design temperature for heating and the July 2.5 percent dry-bulb temperature for cooling, taken from Table C-2 of the National Building Code appendix or from whichever table the authority having jurisdiction requires for the project location. The 2.5 percent January value is the one ordinarily used to design heating systems. Values differ widely between regions, and because many readings come from airports, a city core can be 1 or 2 degrees milder, so a generic national figure is not acceptable.
Heating and cooling loads are calculated separately because they respond to different variables. Heating load depends heavily on the winter design temperature and building envelope, while cooling load also factors in solar gain, occupancy, and internal heat sources like appliances. Equipment must be sized to handle both conditions, so both totals are needed. This tool takes both as inputs and never estimates one from the other.
Equipment size is matched as closely as possible to the calculated load rather than oversized for a safety margin, since oversized equipment cycles more frequently and often provides worse humidity control and comfort. For a furnace, this tool divides the heating load by the furnace efficiency to get the input capacity needed and rounds up to the next standard input size. For air conditioning, it rounds the cooling load up to the next standard size in tons, at 12,000 BTU/h per ton, because manufacturers produce equipment in fixed capacity steps.
No. Format requirements vary by authority having jurisdiction, and some municipalities have specific submission templates or software requirements. Confirming the expected format with the local building department before submission avoids a rejected or delayed permit application.