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)