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

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