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Heating and cooling refers to the way we condition indoor air. In areas of extreme climates, furnaces and air conditioners may be a necessity. In areas with more moderate climates, heating and cooling are nice to have. Air is heated several ways. Burning wood and coal heats up air. Air can also run over hot metal coils. Fans can spread air around making a room feel cooler. Air conditioners run air over coils that condense the moisture in the air and remove the heat.

When you’re really cold, you shiver. That’s your body’s natural reaction to try to warm up, and it takes energy to do all that shaking. Just like your body burns energy to keep warm, energy is burned to keep houses and businesses warm or cool.

At Home
Heating and cooling a home uses more energy, and more money, than any other system in the home. According to the Department of Energy, 44% of a home’s typical utility costs are for heating and cooling. Beyond the personal cost, there’s also an environmental cost. In the United States alone, heating and cooling systems emit over a half billion tons of carbon dioxide into the atmosphere each year, adding to global warming. They also generate about 24% of the nation's sulfur dioxide and 12% of the nitrogen oxides, the chief ingredients in acid rain.

At Work
Businesses also use a lot of energy to heat and cool. Space heating and cooling use 46% of all energy consumed in U.S. buildings. Air-conditioning is the single leading cause of peak demand for electricity and is a major user of chlorofluorocarbons (CFCs)

Since it’s unlikely that homes and businesses will simply turn off air conditioners and furnaces, how can the environmental problems associated with the systems be addressed? Efficiency. The Department of Energy states that advanced energy conversion technology can save 50% of the energy currently devoted to heating and cooling. The improved technologies can also eliminate CFCs completely. Besides saving energy, the advanced systems substantially reduce emissions of carbon dioxide (a greenhouse gas), sulfur dioxide, and nitrogen oxides, which contribute to smog and acid rain (emissions that result from the burning of fossil fuels used to generate electricity).

Technologies like heat pumps, improvements in efficiencies of gas-burning furnaces, and utilizing solar energy can help realize these goals.

There are even simpler things everyone can do, that don’t involve installing entire new systems. Using the "whole-house" approach can have a huge impact on energy bills. Look at your entire house's energy use. By combining proper equipment maintenance and upgrades with appropriate insulation, weatherization, and thermostat settings, you can cut your energy bills and your pollution output in half.


  1. Energy Efficiency and Renewable Energy Network (Department of Energy). "Heating and Cooling." (Online) HTTP://www.eren.doe.gov/consumerinfo/energy_savers/heatcool.html. June 2001.
  2. Energy Efficiency and Renewable Energy Network (Department of Energy). Office of Building Technology, State and Community Programs. (Online) HTTP://www.eren.doe.gov/buildings/building_equipment/natgas.html. June 2001.




Heat Pumps
Heat pumps are the most efficient form of electric heating in moderate climates, providing three times more heating than the equivalent amount of energy they consume in electricity. More

Solar Heating and Cooling
Using passive solar design techniques to heat and cool your home can be both environmentally friendly and cost effective. More

PBS NewsHour Online Links

A look at the air conditioning efficiency debate.

Web Links
Alternatives to AC
Keeping cool indoors when it is hot outdoors is a problem. Air conditioning can be expensive to install and operate. But, there are alternatives to air conditioning.