EPA site with homeowner information for consideration when purchasing or repairing a residential system or heat pump.

Average contractor cost on system replacement for heating and cooling. Descriptions, terminology, specifications.

United States Dept. of Energy's Office of Codes and Standards lists appliances and their energy efficiency and cost of operation.

Consumer reviews, price information, related appliances, buying tips and advice, ratings.

Describes air conditioning from window units up to large industrial applications.

Step-by-step instructions on how to buy an air conditioner.

How to buy a room air conditioner.

Extensive information on all aspects and variations of cooling, air conditioning, including consumer information on how these appliances work and what to look for.