[GreatScott!] examined his air conditioner, whose efficiency declined as the air temperature dropped.

[GreatScott!] examined his air conditioner, whose efficiency declined as the air temperature dropped. By building a circuit that tricked the temperature sensor in the outdoor heat exchanger with a small heater, he switched the control system to a different operating mode and enabled the device to produce cold air again.

In the new device, it was assessed that the issue could have been caused less by a fault than by high indoor humidity or the outdoor condenser requiring specific temperature and pressure ranges. However, he removed the setup he had built to prevent possible damage.

Why it matters

The experiment shows that an air conditioner’s failure to operate at low temperatures may be related not only to its physical capacity but also to how the control system interprets data from its sensors. This distinction indicates that performance problems seen in similar devices should be considered alongside operating conditions and protection logic before being assessed as malfunctions. However, tricking the sensor cannot be regarded as a permanent solution, as it could cause the device to operate outside the temperature and pressure ranges specified by the manufacturer. Although the development is particularly relevant to makers who try to modify devices, the question of whether high humidity or the conditions of the outdoor condenser is the determining factor remains open.