HVAC Design

Psychrometric Processes

In HVAC design the fundamental requirement is to identify the processes that is being performed on the air. These processes can be plotted on a psychrometric chart.

A psychrometric chart is a graphical representation of the thermodynamic properties of moist air at a pressure of one atmosphere. Using this chart, engineers can solve problems without having to do long and tedious calculations.

The psychrometric charts shows the quantities of:

  • dry bulb temperature

  • wet bulb temperature (also known as saturation temperature)

  • dew point temperature

  • relative humidity

  • moisture content (also known as humidity ratio)

  • enthalpy (also known as total heat)

  • specific volume (the inverse of density)

Johansson Engineering Ltd

#9 16728 115St NW

Edmonton, Alberta


T5X 6G6

(780) 476-9670