HVAC and building services calculators
Heating, ventilation and air conditioning for homes and buildings: room air changes, air conditioner size, ducts, moist-air properties and heat loss, each worked from ASHRAE methods with the assumptions stated.
6 calculators- Air changes per hour (ACH) and CFM calculatorAir changes per hour from a room’s airflow, or the CFM, m³/h and L/s for a target ACH, plus the ASHRAE 62.2 whole-house ventilation rate.
- Air density calculatorDensity of dry or humid air from temperature, humidity and altitude or pressure, with specific volume, the ratio to standard air and the density altitude.
- BTU calculator: AC size for a roomAir conditioner size in BTU, kW and tons for a room from its floor area, with the ENERGY STAR adjustments for sun, people and kitchens.
- Building heat loss calculator (U-values)Heat loss of a room or house through walls, windows, roof and floor from U- or R-values, plus ventilation, in W, kW and Btu/h, with yearly heating energy.
- Dew point calculatorDew point from temperature and relative humidity, or humidity from the dew point, with wet bulb, humidity ratio, absolute humidity and enthalpy.
- Duct size calculatorRound and rectangular duct size for an airflow by friction rate or velocity, with the velocity, pressure loss per 100 ft or per metre, and standard sizes.