While the greenest air conditioning system is no air conditioning system, in some parts of the control, central air is necessary during the summer. Air conditioning systems can be real electricity guzzlers, but there are ways to improve the efficiency of your air conditioning system.
On a basic level, make sure that your air conditioning system is the right size for the space it needs to cool. The output of an air conditioning system is measured by the ton, and residential units are usually between one and five tons. It’s not uncommon for HVAC contractors to install a more powerful air conditioning unit than is strictly necessary. The house stays cool, but the AC burns more power than it really needs to. And in a similar “more is not necessarily more” vein, determine if you need air conditioning for an entire home or building, or just a few rooms. If air conditioning is only necessary in a few rooms, window AC units are more economical and will use less energy.
It’s also important to make sure that you are using an environmentally friendly refrigerant. Air conditioning units have, for the most part, used R22, also known as freon. R22 contributes to the depletion of the ozone layer, and since 2010 it is no longer allowed for use in new air conditioning systems, although older air conditioning systems that use R22 can be replenished. It is also less efficient then its replacement, R-410A, also known as Puron, which does not contribute to the depletion of the ozone layer. R-410A can not be used by a system that was built for use of R22. If you have an old system that’s running on R22, consider that the savings from the increased efficiency of a newer system that uses R-410A will at least somewhat offset the initial cost of installing new air conditioning.
Passive cooling, natural ventilation, and other design elements can decrease or eliminate the need for an HVAC system, but energy efficient air conditioning is a green and often necessary option.