See also:

• Business: Construction and Maintenance: Materials and Supplies: Mechanical: Heating, Ventilating, and Air Conditioning  (404)
• Business: Electronics and Electrical: Heating and Cooling  (91)
• Shopping: Home and Garden: Climate Control  (277)

AC-Pal - - Software allows input of data from instrument readings and gives solution to the problem. Definition and help section provides additional information about concepts and functions. Demonstration version available.

Air Conditioning for Home Owners - - Interactive manual includes basic troubleshooting and maintenance tips for do-it-yourselfers. Feedback form provided for technical questions.

Air Conditioning Information and Diagnosis - - Diagnostics chart for troubleshooting. Tips on air filters, refrigerant charging, thermostats, and operation.

Air Duct Calculator - - Input a desired flow rate in CFM, a limiting velocity in FPM, air temperature in degrees F, the length of the duct, and the duct material. The program calculates the duct cross sectional area, the circular duct diameter, and rectangular duct equivalents.

Allexperts Repair Q and A - - Volunteer mechanics answer questions via e-mail. Volunteers can be evaluated based on credentials and user ratings.

Appliance411.com - - List of do's and don'ts for maintenance and repair.

Aprilaire Owner's Manuals - - For humidifiers, air cleaners, thermostats, zone control systems and fresh air exchangers.

Big Blu Manual - - Tutorial illustrating step by step procedures for finding refrigerant leaks.

The Boiler Room - - Forum to post residential steam related questions.

Brazing, Soldering and Welding - - Tutorial illustrating step by step procedures.

BTU Calculator - - Estimate the heating needs of a room, combination of rooms, or an entire home.

Buried Tanks - Home Heating Oil - - Legal, environmental and technical information.

Carbon Monoxide Alert - - Comprehensive site includes safe/unsafe practices, effects, detector placement, and discussion.

Carbon Monoxide Poisoning - - EPA site provides advice on CO detectors, poisoning symptoms and prevention.

Carbon Monoxide Protocol - - Guidelines to determine whether potential exists for this deadly gas to enter a house.

Duct Cleaning - - EPA tips on how to determine if ductwork needs cleaning. Criteria for choosing a contractor.

Furnace Blower Repair - - Short example on replacing bearings and fan belt.

Hannabery HVAC - - Everything from troubleshooting to maintenance and repair.

Hearth.com - - Information on gas, wood, pellet, and coal appliances. Cost comparison of the different fuels.

Heat Pipes - - Fact sheet illustrates the theory and operation. Add-on device for air conditioner to improve de-humidification.

Heating System Maintenance - - Tips on preparing a furnace for winter operation.

HeatingHelp.com - - Find answers to steam heating problems by posting questions for experts or reading excerpts from books about heating.

Home Ideas - - Order form to request free literature on new units and related products.

Homestore.com: Heating How-To Articles - - Wide assortment of tips including programmable thermostats, cleaning air ducts, reducing moisture problems, and basic maintenance.

Honeywell - - Devices include thermostats, humidistats, air cleaners and humidifiers. Everything from manuals to troubleshooting guides to programming instructions to product support.

Howstuffworks.com - - Article that describes air conditioning operation from window units up to large industrial applications.

HVAC Glossary - - Consumer guide to the array of efficiency ratings, abbreviations and acronyms used to describe or explain the products.

HVAC Mechanic - - Information and support on heating, ventilation and air conditioning systems or controls for home owners and professionals. Knowledge base, recalls, forum, glossary, and events.

HVAC Stories at Old House Web - - Advice geared toward historic or older homes.

HVAC-Talk - - Software bulletin board for HVAC contractors, home-owners, do-it-yourself enthusiasts to use for heating and air conditioning concerns.

John Mills Work Page - - Advice from a service manager on buying a new unit, illustrated essay on chimney liners, and a history of brand names.

Learn Ductwork - - Illustrated tutorial on fabricating sheet metal ductwork.

MSN House and Home: Climate - - Overview of systems which contribute to climate within the home - insulation, air conditioners, vents, humidifiers and dehumidifiers, forced air heaters, filters, and thermostats. Illustrations, common problems, and basic repair instructions.

National Refrigerants - - Technical support and regulatory updates; articles, faq, and news.

Ontario Propane Association - - Liquid propane gas serviceman's handbook. Installation and inspection instructions.

Radiant Design Institute - - Illustrations and detailed tutorials for installation of radiant floor heating.

RCD Mastics - - How to locate, repair, and seal ductwork.

Recalls - - Searchable database provided by Consumer Product Safety Commission.

RepairNet - - Flat rate price guide for checking repair costs.

Sound Home Resource Center - - In-depth articles on topics related to improvement, care, and maintenance.

Space Conditioning Systems - - Instructions on maintenance procedures for heating systems. Includes drawings and diagrams.

Warmair.com - - Information on heating system operation, components, troubleshooting and maintenance.