eBuyingGuides: Window Air Conditioning

How to buy a room air conditioner.
http://www.ebuyingguides.com/how/WinAC2_H.htm

Epinions: Air Conditioners

Consumer reviews, price information, related appliances, buying tips and advice, ratings.
http://www.epinions.com/hmgd-Large_Appliances-All-Air_Conditioners

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.
http://www.warmair.com/html/cooling.htm

Carrier

Brand name product site. In addition to Carrier information, also has pages with consumer information such as what size air conditioners to buy for both home and industrial use.
http://www.global.carrier.com/

HowStuffWorks: Air Conditioners

Describes air conditioning from window units up to large industrial applications.
http://www.howstuffworks.com/ac.htm

SoYouWannaBuy.com: Air Conditioner

Step-by-step instructions on how to buy an air conditioner.
http://www.soyouwanna.com/site/syws/aircond/aircond.html

Heating and Air Conditioning Buying Tips

From a sales site, consumer information on buying heating and air conditioning and on hiring a contractor for installation.
http://superior-air.com/hvac.htm?buying_tips.htm~mainFrame

ACDoctor.com: Brand Neutral Air Conditioning Information

Information on buying and maintaining air conditioning systems.
http://www.acdoctor.com/air_conditioning/air_conditioning.htm

Refrigerant-22 Phaseout

EPA site with homeowner information for consideration when purchasing or repairing a residential system or heat pump.
http://www.epa.gov/ozone/title6/phaseout/22phaseout.html

Consumersearch.com: Air Conditioners

The site identifies which products reviewers like and dislike, where they agree or disagree, and why.
http://www.consumersearch.com/www/house_and_home/air_conditioners/index.html

HVAC Mechanic.com

Information and support on heating, ventilation and air conditioning systems or controls for home owners and professionals. Knowledge base, recalls, forum, glossary, and events.
http://www.hvacmechanic.com