Feb10

Humidity and your Air-Con

Categories // On Air

With today's weather in Adelaide getting a bit humid, it will have an effect on your cooling.

Along with the temperature, the weather forecast often talks about humidity, expressed in a percentage.

This is called relative humidity.

"Relative" because it is relative to the amount of water the air, at that temperature, can hold before it needs to drop the excess water in the form of rain, dew or condensation.

Hot air can hold a lot more water than cooler air. If you take warm summer air and cool it down, the relative humidity will increase. It's still the same absolute amount of water in the air, but the capacity of the air to hold the water gets diminished as you cool it.

At some point you will reach the dew point. This is the point when relative humidity equals 100%, and any further cooling of the air means it will need to drop some of that water. Inside your home on the floor tiles.

Dew Point Temperature - Tdp
The Dew Point is the temperature where water vapor starts to condense out of the air (the temperature at which air becomes completely saturated). Above this temperature the moisture stays in the air.
* if the dew-point temperature is close to the dry air temperature - the relative humidity is high
* if the dew point is well below the dry air temperature - the relative humidity is low