Refrigerant-22 Phaseout
EPA site with homeowner information for consideration when purchasing or repairing a residential system or heat pump.

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

Why Buy Energy Efficient Appliances: Room Air Conditioners
United States Dept. of Energy's Office of Codes and Standards lists appliances and their energy efficiency and cost of operation.

Epinions: Air Conditioners
Consumer reviews, price information, related appliances, buying tips and advice, ratings.

HowStuffWorks: Air Conditioners
Describes air conditioning from window units up to large industrial applications.

SoYouWannaBuy.com: Air Conditioner
Step-by-step instructions on how to buy an air conditioner.

eBuyingGuides: Window Air Conditioning
How to buy a room air conditioner.

Warmair.com: Cooling Topics and Tools
Extensive information on all aspects and variations of cooling, air conditioning, including consumer information on how these appliances work and what to look for.