Use and Care Manual

19
Dew-point temperature is the temperature to which a given
sample of air must be cooled so that moisture will start
condensing out of it. When air is saturated, the dry-bulb, wet-
bulb and dew-point temperatures will all be equal. The
horizontal lines in Figure 3 show the dew-point temperature
on the psychrometric chart.
Relative humidity is the amount of moisture in the air relative
to the amount of moisture the air would hold if saturated at
that dry-bulb temperature. Percent humidity is not the same
as relative humidty and is not used in HVAC design. Figure 4
shows the relative humidy curves on the psychrometric chart.
Figure 3.
Figure 4.