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Beginning to End: HVAC Component Lifespans

Beginning to End: HVAC Component LifespansCan HVAC lifespan be accurately predicted? Almost any mechanical device today has an expected service life. This figure is useful to know before you buy in order to get maximum return from your investment. It’s also helpful to start planning in advance for the eventual expense of replacement.

HVAC lifespan is a rough average and varies, depending upon factors including:

  • Proper sizing of a new unit to match the cooling/heating load of the home.
  • Annual preventive maintenance by a qualified professional.
  • Typical daily hours of operation.
  • Local climate—average length of cooling and heating seasons.

Here are some generally accepted figures that predict the median lifespan of HVAC system components:

Central air conditioners:

15 years. Regular annual maintenance can improve this average and is also usually required by the manufacturer’s warranty. Changing the air filter monthly is the most effective DIY procedure to extend service life.

Window A/C units:

10 years.

Gas-fired furnaces:

18 to 20 years. Furnaces have fewer moving parts and accumulate wear and tear slower. Making sure your home is properly insulated and sealed to prevent air leakage helps shorten furnace “On” cycles and extend lifespan further.


After approximately 10 years, residential ductwork is typically leaking conditioned air. While total replacement usually isn’t required, ducts should be pressure-tested to pinpoint leakage then sealed to restore efficiency and performance.


30 years. Digital thermostats are rapidly replacing the old mechanical models that incorporated springs and mercury switches.

Also, keep these two caveats in mind when considering HVAC lifespan: An aging unit that is still operational may be severely outdated in terms of energy efficiency. Rather than waiting for total mechanical failure, replacement now may be a better option in order to start benefitting from lower operating costs, ASAP. Likewise, certain major repairs such as a defective A/C compressor or a cracked furnace heat exchanger are extremely costly and usually not worth the expense if the unit has exceeded two-thirds of its expected service life. Replacing the entire unit is usually the preferred option.

For more about maximizing expected HVAC lifespan, contact the professionals at Beyer Boys.

Our goal is to help educate our customers in the greater San Antonio, Texas area about energy and home comfort issues (specific to HVAC systems).