Air Conditioners Need New Technologies.

• Position: GREENHOUSE GASES

Greenhouse gas emissions from air conditioners are expected to climb as economic growth drives efforts to control both temperature and humidity, according to an analysis by scientists from the National Renewable Energy Laboratory (NREL) and PARC.

While the energy used to power air conditioners has clear implications on greenhouse gas emissions, the impact from removing moisture from the air has escaped in-depth study until now. The researchers showed that controlling humidity is responsible for roughly half of the energy-related emissions, with the other half due to regulating temperature.

"It's a challenging problem that people havent solved since air conditioners became commonplace more than a half-century ago," says study coauthor Jason Woods, NREL senior research engineer.

The researchers point out the increasing need to cool the air is both a cause and an effect of climate change. Even a small amount of moisture in the air can cause people to feel uncomfortable and even damage buildings in the form of mold and mildew.

Controlling indoor humidity through commercially available air conditioning technologies impacts the environment in three ways: they consume a considerable amount of electricity; they use and leak chlorofluocarbon-based refrigerants with global warming...