Angie's LIST Guide to
Heating & cooling
A homeowner's guide to furnaces, air conditioners and ventilation systems maintained by HVAC service providers.
A homeowner's guide to furnaces, air conditioners and ventilation systems maintained by HVAC service providers.
Top Topics
Hvac Quick Tips
Your air conditioning unit becomes 5 percent less efficient every year unless it is serviced.
Read more about air conditioning

An old steam boiler is still in operation thanks to regular maintenance. (Photo submitted by Cindy Christiansen).
Videos
Hiring an HVAC service
Natural gas is an affordable and efficient source of home heating.
HVAC technicians need to to be trained on electronics, plumbing and working with natural gas.
How to find out what your state requires of HVAC companies.
Tips on what to find out before deciding on an HVAC company to hire.
Routine HVAC maintenance
Furnace filters should be changed monthly.
Changing your filter and having regular tune-ups will keep your system running efficiently.
Tips for caring for your furnace.
Your air conditioner becomes less efficient when not serviced regularly
Home heating systems
A natural gas furnace is the most commonly used kind.
"Annual fuel use efficiency" is the ratio of how much heat a furnace produces versus of how much energy it consumes.
Most homes have natural gas furnaces. Here's a step-by-step on how they work.
Air-source heat pumps and geothermal heat can be a good investment.
Air conditioning and home cooling
Air conditioners need to be tuned up annually to maintain efficiency.
Air conditioners work through the physics of evaporation, much like how your body cools through the evaporation of sweat.
The "seasonal energy efficiency ratio" measures an appliance's cooling output versus its energy consumed while running.
Air-source heat pumps and geothermal cooling systems can be effective alternatives to standard air conditioning.
Home energy audits
An energy audit can identify where heat is escaping from your home.
The average household spends more than $2,000 a year on energy, so any new efficiency can lead to monetary savings.
An energy audit will find where drafts are getting into your house and where insulation is ineffective.
Energy auditors use high-tech equipment to reveal how energy is lost.
Duct cleaning and indoor air quality
Whether duct cleaning is worth the investment is a matter of some debate.
American spend 90 percent of their time indoors, relying on mechanical ventilation to keep the air clean.
Many homeowners say they notice a difference after having their vents cleaned, but the EPA says there's no scientific proof it matters.
You can't easily confirm whether the work was done well, so make sure you hire someone you can trust.

