PSYCHROMETRIC CHART FUNDAMENTALS
37
ENGINEERING MANUAL OF AUTOMATIC CONTROL
Psychrometric Chart
Fundamentals
Contents
Introduction ............................................................................................................ 38
Definitions ............................................................................................................ 38
Description of the Psychrometric Chart ............................................................................................................ 39
The Abridged Psychrometric Chart ............................................................................................................ 40
Examples of Air Mixing Process ............................................................................................................ 42
Air Conditioning Processes ............................................................................................................ 43
Heating Process .................................................................................. 43
Cooling Process .................................................................................. 44
Humidifying Process ............................................................................................................ 44
Basic Process...................................................................................... 44
Steam Jet Humidifier....................................................................... 46
Air Washes ...................................................................................... 49
Vaporizing Humidifier ...................................................................... 50
Cooling and Dehumidification.............................................................. 51
Basic Process ................................................................................. 51
Air Washes ...................................................................................... 51
Dehumidification and Reheat .............................................................. 52
Process Summary ............................................................................... 53
ASHRAE Psychrometric Charts ............................................................................................................ 53