Warmair.com

Information on heating system operation, components, troubleshooting and maintenance.
http://www.warmair.com

HeatingHelp.com

Find answers to steam heating problems by posting questions for experts or reading excerpts from books about heating.
http://www.heatinghelp.com

Air Conditioning for Home Owners

Interactive manual includes basic troubleshooting and maintenance tips for do-it-yourselfers. Feedback form provided for technical questions.
http://www.accheckup.com/

Allexperts Repair Q and A

Volunteer mechanics answer questions via e-mail. Volunteers can be evaluated based on credentials and user ratings.
http://www.allexperts.com/getExpert.asp?Category=696

Buried Tanks - Home Heating Oil

Legal, environmental and technical information.
http://www.inspect-ny.com/oiltanks/tanks.htm

Carbon Monoxide Protocol

Guidelines to determine whether potential exists for this deadly gas to enter a house.
http://home.att.net/~cobusters1/coprotocol.htm

Heating System Maintenance

Tips on preparing a furnace for winter operation.
http://muextension.missouri.edu/xplor/hesguide/housing/gh5981.htm

Duct Cleaning

EPA tips on how to determine if ductwork needs cleaning. Criteria for choosing a contractor.
http://www.epa.gov/iaq/pubs/airduct.html

Sound Home Resource Center

In-depth articles on topics related to improvement, care, and maintenance.
http://www.soundhome.com/topics/topic.shtml#energy

Hannabery HVAC

Everything from troubleshooting to maintenance and repair.
http://www.hannabery.com

Learn Ductwork

Illustrated tutorial on fabricating sheet metal ductwork.
http://www.thesheetmetalshop.com

Hearth.com

Information on gas, wood, pellet, and coal appliances. Cost comparison of the different fuels.
http://www.hearth.com/what/specific.html

Carbon Monoxide Alert

Comprehensive site includes safe/unsafe practices, effects, detector placement, and discussion.
http://www.homesafe.com/coalert/

HVAC-Talk

Software bulletin board for HVAC contractors, home-owners, do-it-yourself enthusiasts to use for heating and air conditioning concerns.
http://hvac-talk.com/

Aprilaire Owner's Manuals

For humidifiers, air cleaners, thermostats, zone control systems and fresh air exchangers.
http://www.resprod.com/default.asp

BTU Calculator

Estimate the heating needs of a room, combination of rooms, or an entire home.
http://hearth.com/calc/btucalc.html

Brazing, Soldering and Welding

Tutorial illustrating step by step procedures.
http://www.jwharris.com/home/

RepairNet

Flat rate price guide for checking repair costs.
http://www.repairnet.com/

Appliance411.com

List of do's and don'ts for maintenance and repair.
http://appliance411.com/links/Helpful_Tips/Air_Conditioner/

Big Blu Manual

Tutorial illustrating step by step procedures for finding refrigerant leaks.
http://www.refrigtech.com/bigblumanual1.html

Furnace Blower Repair

Short example on replacing bearings and fan belt.
http://www.misterfixit.com/htrblowr.htm

Honeywell

Devices include thermostats, humidistats, air cleaners and humidifiers. Everything from manuals to troubleshooting guides to programming instructions to product support.
http://www.honeywell.com/businesses/page6_5.html

HVAC Glossary

Consumer guide to the array of efficiency ratings, abbreviations and acronyms used to describe or explain the products.
http://www.hvac-city.com/hv01002.htm

Air Conditioning Information and Diagnosis

Diagnostics chart for troubleshooting. Tips on air filters, refrigerant charging, thermostats, and operation.
http://www.longviewweb.com/index.htm

Carbon Monoxide Poisoning

EPA site provides advice on CO detectors, poisoning symptoms and prevention.
http://www.epa.gov/iaq/pubs/coftsht.html

Gas Furnace Alert

Warning about the potential danger if flue pipe is not replaced when a modern high efficiency furnace is installed. (click "alert" to get to page)
http://www.meier-and-sons.com/

HVAC Help for the Homeowner

Experienced mechanic shows how to get help from the web. Includes advice from other mechanics and numerous searches of alt.hvac where many industry experts have answered a variety of questions.
http://home.att.net/~alt.hvac/owner.htm

Heat Pipes

Fact sheet illustrates the theory and operation. Add-on device for air conditioner to improve de-humidification.
http://www.heatpipe.com/heatpipes.htm

Home Ideas

Order form to request free literature on new units and related products.
http://www.homeideas.com/category.pl?site=hi&category=hvac

The Boiler Room

Forum to post residential steam related questions.
http://www.boilerroom.com/homeforum.html

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.
http://www.ac-pal.com/index.html

Howstuffworks.com

Article that describes air conditioning operation from window units up to large industrial applications.
http://www.howstuffworks.com/ac.htm

Space Conditioning Systems

Instructions on maintenance procedures for heating systems. Includes drawings and diagrams.
http://www.msue.msu.edu/msue/imp/mod02/01500601.html

Radiant Design Institute

Illustrations and detailed tutorials for installation of radiant floor heating.
http://www.radiantdesigninstitute.com/

Homestore.com: Heating How-To Articles

Wide assortment of tips including programmable thermostats, cleaning air ducts, reducing moisture problems, and basic maintenance.
http://www.homestore.com/HomeGarden/homeimprovement/howtos/howtos/DefaultHeating.asp

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.
http://www.johnmills.net/work/workpage.html

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.
http://www.connel.com/freeware/airduct.shtml

Ontario Propane Association

Liquid propane gas serviceman's handbook. Installation and inspection instructions.
http://www.propane.ca/Resources/

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.
http://www.hvacmechanic.com

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.
http://houseandhome.msn.com/improve/climate.aspx

RCD Mastics

How to locate, repair, and seal ductwork.
http://www.rcdmastics.com/

Recalls

Searchable database provided by Consumer Product Safety Commission.
http://www.cpsc.gov/cpscpub/prerel/prerel.html

National Refrigerants

Technical support and regulatory updates; articles, faq, and news.
http://www.refrigerants.com/

HVAC Stories at Old House Web

Advice geared toward historic or older homes.
http://www.oldhouseweb.com/stories/How-To/HVAC/