See also:

• Business: Construction and Maintenance: Materials and Supplies: Mechanical: Heating, Ventilating, and Air Conditioning  (402)
• Business: Electronics and Electrical: Heating and Cooling  (108)
• Shopping: Home and Garden: Climate Control  (227)

• 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 Information and Diagnosis - Diagnostics chart for troubleshooting. Tips on air filters, refrigerant charging, thermostats, and operation.
• 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.
• 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 - Safe and 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.
• 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.
• National Refrigerants - Technical support and regulatory updates; articles, faq, and news.
• Ontario Propane Association - Liquid propane gas serviceman's handbook. Installation and inspection instructions.
• 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.