What Is a Manual J Load Calculation?
A Manual J load calculation is the industry-standard method for determining exactly how much heating and cooling capacity a specific home needs, based on square footage, insulation, window area, orientation, and other factors. It's the proper way to size equipment, rather than guessing based on the old system's rating.
Why It Matters to You
Sizing a replacement system off the old unit's rating alone can carry forward a sizing mistake — a proper load calculation accounts for your home's actual characteristics.
Practical Guidance
When getting quotes for a full system replacement, ask whether a load calculation was performed rather than the new equipment being sized to simply match the old unit.
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