With an estimated 4 million air conditioners likely to fail this summer in the USA, deciding whether to spend the money on a new system is going to be a common predicament.

What isn’t so well-known is that early next year, a government-required shift in what air-conditioning and heat pump systems use to regulate temperature will take effect.

For the past several decades, R-22, a gas refrigerant and HCFC (hydrochlorofluorocarbon) has been an air-conditioning standard. If it leaks, however, R-22 can contribute to ozone depletion, says Deb Berlin, an Environmental Protection Agency spokeswoman. The ozone layer is responsible for absorbing most of the sun’s high-frequency ultraviolet light, which can be harmful to life on Earth.

But as of Jan. 1, R-22 will no longer be on the market and will be replaced by a more environmentally friendly and energy-efficient alternative. The change was ordered in a 1992 amendment to the Montreal Protocol, an international treaty created to protect the ozone layer.

“There is a rapid ramp-down for the manufacturing of HCFCs,” says John Schneider, business vice president for Emerson Climate Technologies, which advises manufacturers on energy-efficient technology. R-22’s successor is R-410A, an HFC (hydrofluorocarbon) without chlorine, the chemical that contributes to ozone depletion. After the turn of the decade, R-410A will be the refrigerant placed into new air-conditioning systems, which will not be compatible with R-22. Conversely, current air-conditioning systems cannot use R-410A without a serious overhaul, because it is compressed at a much higher pressure and requires different equipment, Schneider says.

Older refrigerant will be harder to find

The phase-out of R-22 does not mean service and used parts will be unavailable for older air-conditioning models, Schneider says. The Montreal Protocol calls for a gradual elimination of all HCFC refrigerants in new equipment in developed countries by 2010. Service for older models could disappear by 2020.