Utility closet/Furance


A furnace is one way to heat a home. A furnace is generally expected to last about 20 years. Current furnaces tend to be more efficient than older ones.

Buying a furnaceEdit

There are several reasons to buy a furnace:

  1. first and most importantly, safety issues
    a faulty furnace can be a fire hazard or put out carbon monoxide, which can be deadly
  2. you don't have one yet and need one (for example in a new house)
  3. the old one is irreparably broken
  4. the old one is inefficient and won't last much longer

If you have the flexibility, consider purchasing a furnace during the spring, summer or early fall months when business may be slower for the companies that install furnaces. (Although some also handle Air conditioning, so the hottest part of the summer is probably busy for them too.)

In the U.S. the purchase price usually includes the labor, parts and materials, installation, some warranty as well as the equipment.


  • energy efficiency
  • initial cost and costs to run over time (Total Cost of Ownership)
  • maintenance record
  • sizing, that is how large a space it can heat
  • size, how much space it takes
  • installation
  • features: air cleaning, humidifier
    • Some furnaces have an air cleaner, most have a filter of some sort, so that as the air is forced to circulate it is also cleaned.
    • As air is heated, its relative humidity goes down. So some furnaces have a humidifier to keep the humidity of the air higher.

Terms, abbreviations and definitionsEdit

  • AFUE - annual fuel utilization efficiency
  • ASTM - American Society for Testing and Materials
  • BTU - British Thermal Units
    the amount of heat it takes to raise one pound of water one degree Fahrenheit
  • Electronic Air Cleaner
  • ENERGY STAR qualified - for oil and gas furnaces requires an AFUE of 83% or higher
  • Heat Exchanger
  • Heat Pump
  • Humidifier
  • SEER - Seasonal Energy Efficiency Ratio (mostly applies to air conditioning)
  • Thermostat

Keeping the furnace workingEdit

The furnace will not work properly if the air cannot flow properly into and out of it. Check to make sure the air intake and exhaust are both clear. If the snow is high enough to block the air intake, your furnace cannot work.

Some furnaces have a drain pipe. Pouring warm-hot water with some vinegar or bleach through it can help keep the pipe clear and kill some stuff like mold. Do this at the beginning and end of each heating session.

Periodically check for leaks. Is there water where there shouldn't be? Or signs that there were puddles there? Condensation can also be a sign of a possible problem.

High efficiency furnaces have a fan that operates continuously. This also has the advantages of keeping the air circulating and evening the temperature throughout your home.


furnace and water heater (utility closet)




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