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Sound sizing considers the building load, climate and heating strategy. Ask for a recognized load calculation before selecting equipment.
Key decisionDecision: require a recognized load calculation and design objectives. A BTU-per-square-foot rule is not enough.
The home comes first
Insulation, air sealing, windows, orientation, air distribution and climate all change the load. Two homes with the same floor area can require different solutions.
Undersizing and oversizing
An undersized system may rely more heavily on backup heat and miss expected savings. An oversized system can short-cycle in mild weather, reduce comfort and increase wear.
Evidence to request
Natural Resources Canada recommends a load calculation using a recognized method such as CSA F280. Also ask for published capacity at design temperatures and the backup-heat strategy.
Official sources
Updated :
Programs and criteria can change. Always verify the official source before making a decision.