HVAC Calculators and Tools

A growing collection of free calculators for HVAC engineering work, starting with a full psychrometric calculator and interactive psychrometric chart.

Psychrometric chart with a plotted air state

Psychrometric calculator

Solve the full moist-air state from dry-bulb temperature plus wet-bulb, relative humidity, or dew point, with the point plotted on a psychrometric chart.

Duct friction chart with a selected round duct size

Duct calculator

Size round and rectangular ducts by friction rate and velocity, check flat-oval ducts, and read it all on an interactive friction chart.

Split system cross plot

Balance condensing-unit and evaporator (DX) capacity to find the saturated suction temperature, including suction line loss.