The principal behind solar thermal air-conditioning is to replace a large compressor required to compress refrigerant to produce a cooling effect with a refrigerant expander in the form of a thermal heat exchanger.
The increase in refrigerant pressure is the same but without the use of electricity to operate the compressor.
The system still needs electricity to operate electrical components, however, large savings can be made by reducing the size of the compressor and expanding the gas instead.
Visually the systems look the same except for the addition of the solar thermal panel mounted next to the condenser.
It does not have to be in direct sunlight as it relies on ambient temperature rather than direct solar radiation as required for PV solar power systems.
The most accurate measurement of air-conditioning performance is the Energy Efficiency Ratio or EER.
It is simply a ratio of the maximum thermal energy (cooling), divided by the maximum electrical energy(electricity), required to operate the system.
The average EER for solar thermal systems is 3.
88 compared with the full power continuous output EER of conventional systems of around 2.
4.
The savings in electricity provide a financial benefit along with the relief to the electricity Grid at peak usage times.
As the system is economical to run it can be operated 24hrs per day.
This eliminates the inefficient operation of systems set to maximum power to quickly cool a home which has been heated all day.
This also eliminates the associated peak in the electricity demand when consumers arrive home from work.