Air conditioning – Why does my air conditioner dehumidify the air?

Question

Why does my air conditioner dehumidify the air?

Answer

An air conditioner dehumidifies the air because this is a direct consequence of its cooling function.

Here’s how it works:

1. Warm air from the room is drawn in.
2. The air flows over a very cold evaporator (heat exchanger).
3. The air cools down. Cold air can hold less water vapour than warm air.
4. Water condenses. As soon as the air is cooled below its dew point, excess moisture condenses as water on the evaporator – much like on a cold drinks glass in summer.
5. The condensate is drained away. It flows into a drip tray and then out via a hose, or it evaporates outside along with the warm exhaust air.

This not only makes the air cooler, but also drier.

Why is this pleasant?

The lower humidity has several advantages:

• You perceive the room temperature as more comfortable.
• Sweat can evaporate more easily, which cools the body more effectively.
• It makes it harder for mould to form.

Can an air conditioner simply dehumidify?

Yes. Our air conditioners have a ‘Dry’ or ‘Dehumidify’ mode. In this mode, the compressor operates in such a way that as much moisture as possible is removed from the air, whilst the room temperature drops only slightly. This is particularly useful on muggy days.

In short: an air-conditioning system dehumidifies the air because, as the air is cooled, water vapour condenses on the cold heat exchanger and is drained off as liquid water. This is an unavoidable yet desirable side-effect of the cooling process.

Do you have any other questions that we haven’t yet answered? No problem – our advisory team will be glad to help: contact ecofort.