Heating Load Calculator
Calculate the heating load in BTU/h and kW based on area, insulation R-value, and indoor/outdoor temperature difference.
How to Use the Heating Load Calculator
- Enter the conditioned area in square feet.
- Enter the insulation R-value.
- Enter indoor and outdoor design temperatures in °F.
- Click Calculate for BTU/h and kW heating load.
使用场景
- •Residential furnace sizing.
- •Heat pump selection.
- •Energy audit calculations.
- •Building envelope performance assessment.
公式
BTU = U × Area × ΔT, where U = 1/R. kW = BTU × 0.000293.
常见问题
What is R-value?
R-value measures thermal resistance. Higher R-value = better insulation. R-13 is typical for walls; R-38 for ceilings.
What outdoor temperature to use?
Use the design heating temperature — typically the 1% or 2.5% coldest temperature for your location.
Does this include infiltration?
No — infiltration and ventilation loads are not included. Add 10–20% for a more complete estimate.