How to Calculate Heat Load
What is Heat Load?
Heat Load Calculator helps contractors and tradespeople accurately size, spec, and estimate materials and systems.
Formula
Heat Load = U-value × Area × Temperature Difference (BTU/hr)
Step-by-Step Guide
- 1Calculate heat transmission through each building element
- 2Apply the formula using your project measurements
- 3Add required safety factors or waste allowances per code
Worked Examples
Input
Wall: 0.07 U × 500 sf × 60°F delta
Result
Heat Load = 0.07 × 500 × 60 = 2100 BTU/hr through wall
Common Mistakes to Avoid
- ✕Not applying code-required safety factors or derating
- ✕Forgetting to account for waste and cut losses in material estimates
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