Basic knowledge of air conditioner
The principle of compression
Air-conditioning works by exchanging heat from inside a room to outside the room. It does this by compressing refrigerant gas, and then expanding it. When the gas expands, it gets cooler. The gas is compressed by a machine called a compressor, which is noisy. Bigger compressors produce more powerful cooling and more noise.
Window type air conditioner
All the components of these machines are in a box that hangs out of the room. Switch one on and listen carefully. You will hear the compressor noise. Window-type air-conditioners are less desirable because of the noise.
Split type air conditioners
This type is quiet because the compressor is installed outside the building, separate from the air-conditioning unit which installed inside the room. In older generation of split-type machines, the compressor is either running or not running.
Inverter split-type air conditioner
The new generation of air-conditioners features variable speed compressors. This innovation allows the compressor to run slower when less cooling is required. You will save a lot of energy with one of these because electricity fee is not cheap in Hong Kong.
Window Type/Split type/Inverter split-type heat pump air-conditioner
If you expect your unit to have a warm temperature in the winter, you may consider to choose an air-conditioner with heat pump function. When the room temperature rises and reaches the set temperature, it will change to a low-capacity operation. As a result, inverter air conditioners are more energy-saving and comfortable than non-inverter air conditioners.