In the 15+ years of my experience with ACs of all shapes and sizes and types, I've observed that many times, we require a reduced level of cooling, compared to the maximum cooling capacity of an AC. In such situations, we wish that the AC throw semi-cooled air at us, because it feels hot if we turn it off, and it feels cold if we turn it on.
However, this is not possible with today's ACs. They can only be turned "full on" or "full off". They cannot be made to reduce the coolness of the air that they throw (essentially, the extent of cooling performed by an AC's compressor cannot be varied), and hence some of the following tricks are used to approximate the effect of reduced cooling
- Varying the fan speed
- Use of a thermostat
- Mixing of warm air
- No saving in electricity, for tricks 1 and 3
- Non-optimum user-experience, for trick 2 (I've observed that use of thermostat sometimes makes the room too-cool or too-warm, at least temporarily)
And so I wish that we had a sort of truly variable compressor, which shall allow me to actually vary the extent of cooling. Most importantly, its power consumption shall be directly proportional to the extent of cooling. This potentially revolutionary refrigeration-compressor shall allow me to choose 50% cool air on days when the weather is cool, so that I can save myself from uncomfortably-cold air, and also save 50% of the electricity.