Air conditioners are indispensable in many parts of the country, but their environmental impact has long been a source of controversy. In particular, the coolants that were used in the earliest air conditioners, chlorofluorocarbons (CFCs) have done quite a bit of damage to the Earth’s protective ozone layer.

When this affect was discovered, countries all over the world acted to have them phased out of production and use in air conditioning. While CFCs have not been produced since 1995, there are still many air conditioning units functioning today that use CFCs. As these units wear out, of course, the CFCs will gradually disappear from use altogether.

Another type of coolant that is commonly used in air conditioners is hydrochlorofluorocarbons (HCFCs). These have a slightly lower environmental impact than their cousin CFCs, but they are still not ideal in terms of preserving the ozone layer and impeding the progress of global warming. HCFCs are gradually being phased out as well, and they will no longer be produced at all by 2030.

However, it is still possible to buy air conditioners that use HCFCs as a coolant, and if you can avoid this, you should. HCFCs are not nearly as environmentally friendly as some of the other options on the market, and if you are concerned about the effect that these types of chemicals can have on our environment, it is best to steer clear of air conditioners that use HCFCs.

So what coolants are considered environmentally friendly? Well, there are actually two options in this regard. The first are hydroflourocarbons (HFCs). Although they are quite similar to CFCs and HCFCs, HFCs do not contain chlorine and so do not do the type of damage that their predecessors were capable of. You can find air conditioners that use HFCs relatively easily by looking for an “ozone friendly” label on the box.

Refrigerant blends are also becoming a more and more popular environmentally friendly coolant solution for air conditioners as well. Although these types of coolants typically cost more to produce and so can drive up the cost of the air conditioners that use them, they should begin to come down in price as they are more widely adopted across the industry. Just as with HFCs, look for the “ozone friendly” label to identify air conditioners that use refrigerant blends as coolants.