Aircon modes demystified

Have you ever looked at your aircon remote and wondered what the ‘Mode’ button actually does. Thus far, my interaction with my aircon has been primarily to switch it on/off and make minor modifications in temperature every now and then. As a result, when my house-mate asked me to put our aircon in ‘Dry mode’, I gave him a quizzical look. As far as I was concerned, there was no difference except the constant change of one icon on the bottom left of my aircon remote as I kept pressing the button.

Embarrassed by my lack of awareness, I started researching into the pros and cons of the different aircon modes and the energy saving benefits that some of them provide –

  • Cool mode

This is the default mode that your air conditioner runs on over 90% of the time. In this mode, the fan and compressor are both turned on till such time as the temperature of the room reaches the target temperature that the aircon is set at. The compressor cuts off once this temperature is reached. However, the fan continues running until such time as the temperature rises by 1°C. Once this happens, the compressor kicks in once more. The above cycle continues on.

  • Fan mode

This is a mode that is rarely used, especially in a country like Singapore. In this mode, the compressor is permanently switched off while the fan runs continuously.

  • Dry mode

This mode is often confused with the cool mode. However, you only have to look at the icon on your aircon remote to know the difference! The primary objective of this mode is to reduce the humidity in the room. This setting is ideal for the rainy season, where the temperature may not necessarily be very high. In circumstances of high humidity, even lower temperatures are unbearable. As a result, the dry mode increases the comfort factor of the room by dehumidifying the room to an acceptable level (not entirely!).

The difference in aircon operation between the cool mode and dry mode is that to reach the target temperature, the fan begins running to suck in the moist air, while releasing dry air. The compressor facilitates this condensation as well. Once the target temperature has been reached, both the fan and the compressor cease to operate. As a result, the humidity in the room rises, and with it, the temperature. Once there is a rise in temperature of 1°C, both the fan and compressor kick in once more. The above cycle continues on.

  • Energy saving mode

This mode may not be found on all aircons, as it is unique to certain brands of air conditioners. The primary difference in operation between this and the cool mode is that in the energy saving mode, when the target temperature is reached, both the fan and compressor shut off.

In cool mode, the fan operation also takes in the in-room air to check the temperature. When there is a noticeable change, the compressor cuts in. However, in the energy saving mode, the fan restarts every few minutes to detect whether there is a noticeable rise in temperature. If so, the compressor then cuts in and cools the room. The above cycle continues on.

Read on to find out more about the pros and cons, and the energy impact of each of the modes!

Pros and cons of aircon modes
Pros and cons of aircon modes