HVAC & Refrigeration

Basic

Relative Humidity

Vapour pressure as a percentage of the saturation pressure.

Formula

RH = \frac{p_v}{p_{sat}} \times 100

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Variables

RHRelative humidity (%)

p_vActual vapour pressure

p_{sat}Saturation pressure

Example

p_v=1200, p_sat=2340: RH = 51%

Did You Know?

Warm air holds far more moisture, so the same water content gives a lower RH as temperature rises.

hvac humidity rh

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