Particularly appreciated in hot climates, air conditioners could be one of the highest electrical consumption items, depleting the local produced energy capacity, limiting the use of solar generators or keeping high the demand for fuel for generators.
New technologies in air conditioners such as the inverter ones have made them more power efficient, these models are therefore highly recommended instead of oldest models. Inverter type air conditioners have a far better regulation mechanism than the older on-off thermostatic control types and are less noisy.
The efficiency of an air conditioner is measured by it's Coefficient Of Performance (COP), the number of Watts transferred by the system for one electrical Watt consumed. Inverters types have usually a COP equal of better than 4, while traditional models have a COP between 2 to 3.5.
This efficiency is sometime given as SEER (Seasonal Energy Efficiency Ratio). 1 SEER = COP x 3.792.
The temperature on which the air conditioner is tuned has an important impact on the consumption. Where external temperature is high, the reference temperature does not need to be set more than 7 to 8 degrees maximum. There is no need to set this temperature lower than 25 °.
Air conditioner filter should be regularly changed to keep the energy consumption low, usually 4 to 6 times per year.
In dry environments, water cooler (also called adiabatic cooler) could also be used. The electrical consumption of these models are lower than normal air conditioners, but they may need a significant level of water, and are increasing air humidity.
Temperature control between 20 to 35 °
Thermal capacity: in BTU, as needed
COP: as higher as possible, better than 4
Cooling fluid: R410a or other ozone layer friendly fluid. R22 (Freon) should not be used.
Availability of local maintenance