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Heating/Ventilation/Air Conditioning

Fan from Minka Air; radiator from Radical Radiator Restorations

Heating?  Start with What You've Got

  • Radiators?  How long since they've been cleaned and bled?
  • Air filters?  Put on an every-3-month replacement schedule.  
  • Baseboards and registers?  Are they clean and free from furniture, rugs and draperies?
  • Leaky ducts?  Seal them.
  • Is your thermostat accurate?  A maintenance check may help.
  • Had a furnace tune-up latelly?  Perhaps it's time to do that.


Cooling? Some Cost-effective Strategies
  • Use ceiling fans (preferably Energy Star-rated) to circulate air.
  • Like the feel of fresh air?  Use a window fan to draw air from the least windy side of your home, then exhaust that air on the windiest side.
  • Live in a dry or temperate climate?  Consider installing a whole-house fan to cut your AC bills.
  • Windows get too much direct sunlight?  Use landscaping elements, trellises or awnings  to maximize shade.  
  • Air conditioner?  Have you cleaned the filters, coils and drain channels?
So You Need a Replacement? What to Consider

Heating and cooling are typically the biggest items on your energy bill.  If you must replace your system's equipment, however, your choices may be limited by that system as well as by cost and by available energy sources.  Still, the goal of replacement is to buy the most efficient system you can afford.

The Department of Energy's come up with information on heating fuels, their relative costs and efficiencies.  The American Council for an Energy-Efficient Economy (ACEEE) calculates your return on investment and the efficiency percentage that qualifies for an Energy Star on each type heating unit, with a brief rundown of furnaces, boilers and heat pumps.

Size Matters

Modern home heating systems of all types have improved in design, efficiency and controls.  Although not all new heating systems have an AFUE rating high enough to win an Energy Star, they're more efficient than now than they were even ten years ago.  Again, the higher the AFUE, the more energy you'll save in the long run.

If you've decided to buy a new heating system and have done your homework as to what might work best for you, the next task becomes sizing the system properly for your home.  Some gas and electric utility companies offer this sizing service at little or no cost.  

What does size depend on?  The Air Conditioning Contractors of America have published Manual J, the essential guide to heating unit sizing, and Manual D, the essential guide to duct design.  There are computer programs and worksheets based on those guides that aid in calculations.  Be sure your contractor has based his bid on those guides, and ask for a copy of those calculations.


Actually, that step may also help you choose the right contractor for your project.

Reference Corner

One Btu (British thermal unit) equals the amount of heat energy needed to raise the temperature of one pound of water by one degree Fahrenheit at a constant pressure on one atmosphere.   It describes the energy content (heat value) of fuels, as well as the power of heating and cooling systems.

Annual Fuel Utilization Efficiency (AFUE) measures how effectively a heating system turns its fuel into heat.  The higher the percentage, the more efficient the system.