Single-Speed vs. Variable-Speed Furnaces

If you are in the market for a replacement furnace, you may have been doing some research to figure out which type of unit will be best for your family’s heating needs. During your hours spent online trying to determine how many BTUs your replacement needs, as well as what size and heating capacity will be best, you may have come across the following terms: single-speed and variable-speed. The average homeowner probably hasn’t heard these terms before, and if they have, they may not have a clue what they mean.

What do “single-speed” or “variable-speed” mean when it comes to a furnace?

It’s important to note that these terms refer to the furnace’s blower motor.
Most traditional furnaces are built with single-speed functionality. This means that they work at their fullest capacity at all times when running. So, regardless of whether it’s 45 degrees F, or -10 degrees F, your furnace is working with the same heating capacity to warm your home.

With a variable-speed furnace, there are a number of blower motor speed settings, including low and high capacities. This means that on a slightly chilly day, your furnace will only be operating with low capacity. However, on the coldest day of the season, your heater will be running at its highest capacity. Different speeds help make your furnace as efficient as possible.

Pros and cons of single-speed vs. variable-speed furnaces



  • Single-speed units are often less expensive than variable-speed systems.
  • These heating systems can generally be installed in any setting with any standard ductwork.
  • Most technicians have extensive experience performing repair and maintenance work on these systems, while they may have little experience with variable-speed units. 


  • Their lifespan isn’t as long as a variable speed system. On average, they last up to 15 years.
  • They run at full capacity during each cycle, so they aren’t very efficient. 




  • Variable-speed furnaces generally only run at high capacity during the coldest portion of the heating season, so they are efficient.
  • The blower motor is effective at removing excess humidity from the air during the cooling season.
  • The units use nearly six times less energy when compared with single-speed systems.
  • Variable-speed heaters often last for 15-20 years.
  • Variable-speed furnaces generally are fairly quiet while running.


  • Variable-speed systems are slightly more expensive than traditional single speed units.


Protect your new furnace


Once you have determined which furnace is perfect for your family’s heating needs, protect your new investment with a plan from Pivotal Home Solutions. We offer comprehensive heating repair and heating maintenance coverage in many of our territories. If you’re ready to learn more, please give us a call at 888-801-5057.