Variable speed vs. multi-speed blower: What’s the difference?

Let us guess: you’re comparing two furnaces and one is more expensive because it has a “variable speed” blower, as opposed to a “multi-speed” blower on the less expensive model.

So, of course you’re wondering, “What the heck is the difference between a variable speed and a multi-speed blower? And is the variable speed worth the extra cost?”

We’ll give you the dirty details.

Difference between variable speed and multi-speed blower

The multi-speed blower is the new “standard” blower type. The variable speed blower is the “premium” blower type, which gives you these extra benefits:

  • Saves you big on electric bills by consuming less electricity
  • Operates quietly by ramping up slowly
  • Offers better humidity control
  • Offers better air quality control
  • Works well for zoning, which allows you to customize your comfort in different areas of your home, decreasing your energy bills as a result

To understand how the variable speed blower delivers these benefits, let’s delve into how the variable speed works compared to the multi-speed blower.

Variable speed blower: Works like cruise control

So, you know how when you set your car on cruise control, the engine precisely adjusts to maintain a steady speed?

Well, the variable speed blower works the same: the motor precisely—and automatically—adjusts to keep airflow at a specified level, even if it’s working against resistance. Got a dirty air filter? The variable speed blower ramps up to deliver enough airflow (you should change that air filter though).

Even when your AC or furnace isn’t running, the variable speed blower stays on most of the time, but at a low, energy efficient setting. Operating in this way, it can constantly clean your air if you have an air cleaner or constantly humidify your air if you have a humidifier.

Multi-speed blower: Works like a ceiling fan with a few fixed speeds

The multi-speed blower can also adjust airflow like a variable speed blower—but it’s less precise. A multi-speed speed blower works less like a gas pedal and more like a ceiling fan ( low, medium, high settings).

Multi-speed blowers can have up to 5 preset speeds, changing based on your airflow needs.

“Is the variable speed blower worth the extra cost?”

That’s entirely up to you and your needs.

Do you need better air quality because you have family members with bad allergies and asthma?

Does your home have dry air, and you wish you had better humidity control?

Are you a light sleeper and need your blower to keep quiet so you can catch some Zs?

If so, then go with the variable speed blower. Because it’s main selling point isn’t cost efficiency; it’s comfort.

Got more questions? Ask our comfort experts for advice (It’s free).