HVACopediaGas flow & combustion air
Gas volume from the BTU/h input and the air it needs.
More heating calculators
Combustion analysisNet stack temperature, efficiency and what the readings meanElectric heat: kW, BTU/h & ampsConvert an element size and find the current and breakerQuick heat lossWall, window or roof loss, and air leakage loadPipe expansionHow much a hot water pipe grows when it heats upDegree daysHeating or cooling degree days from the daily high and lowWall R-value & U-valueAdd up layers; get R, U and heat flow through the wall
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Calculation aids and reference figures for licensed technicians. Always follow the manufacturer’s data plate and manual for the exact model, and local codes. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Pressures are typical saturation values and change with load and airflow.