Multi-Speed vs. Variable Speed Furnace Blower: What's the Difference?

Two popular choices of furnace blowers on the market today include the multi-speed blower and the variable speed blower. Both offer significant advantages in comfort and long-term savings over older single-speed motors. That said, the type you choose largely depends on its operational efficiency and the price you have in mind. The experts from have taken a closer look at both to see when each one is the right option.

What Are Multi-Speed Blower Motors

Multi-Speed Blower MotorsIn the past, most homes had a single-stage furnace blower. This means it runs either "on" or "off" with no in-between speeds. When the heat drops below the thermostat setting, the furnace starts up and blows warm air throughout the house.househouse. Once your home's temperature reaches the thermostat setting the furnace stops blowing. There are "cool spots" or times when the temperature is between the two settings.

You can compare this to cooking a pot of soup on the stove with the burner either on or off. This is not efficient and wastes energy. During the warm months, the cooling is also inconsistent.

A multi-speed furnace blower motor overcomes these problems because it has two operating settings instead of just one. Basically, one speed is for "cool" and the other is for "hot". This is more efficient and the home's comfort level is more even throughout the day and night.

Multi-speed blowers are the new standard in furnaces. When it's time to replace your old single-stage system, this is a good choice. HVAC contractors are familiar with multi-speed furnace installation and may recommend them because they cost less than variable speed blowers.

What Are ECM Blower Motors

An electronically commutated motor (ECM) is a technological advance for home furnaces and air conditioners. It improves much of the overall performance and efficiency of an HVAC system by making adjustments based on data monitoring. General Electric developed ECMs in 1985. Since then, they have played a major role in many leading brands of furnaces and air conditioners.

When you upgrade your current AC or furnace, do not keep the older blower; it is not as efficient as an ECM. You will be wasting money because it will not perform up to standards with a new system. Upgrade to an ECM motor and you will enjoy lower energy bills.

What Are Variable Speed Blower Motors?

Variable Blower Motors A variable speed furnace blower motor is a step above a multi-speed blower. This new technology has an ECM motor with a speed controller. It is more like a continuous blowing approach; providing the precise heat or cooling output your home needs at any given time day or night.

The air quality is also improved in your home with a variable speed blower. This occurs because the blower circulates air even when the heat is not running. Air is continually passing through each room through the return ducts to the furnace filters that catch more dust, lint and other debris. This is great for people with allergies or other respiratory disorders. It is also effective for homes with pets and means less dusting.

What Are the Benefits of Multi-Speed vs. Variable Speed?

 Benefits of Multi-Speed vs Variable Speed A multi-speed blower has several benefits over a single-stage furnace blower:

  • Lower maintenance costs
  • Fuel efficiency
  • Lower energy bills
  • Better humidity control
  • Better air quality control

Maintenance costs typically are lower because it is not an on-and-off system. Single-stage blowers turn on and off more often, which is hard on working parts. This tends to wear out your system earlier and uses more energy to cycle more often or colder days and nights.

Variable speed air handlers have additional advantages over both single-stage and multi-speed blowers.

  • More consistent heating and cooling
  • More noise reduction
  • Cleaner air in each room
  • Greater fuel efficiency
  • Better electricity efficiency

These advantages come from how the blower system works. It starts blowing at a slow speed and increases as the heating or cooling needs to increase. You don't notice the noise as much - in fact, it is less noisy than other types of blowers. The air is continually being cleaned with a variable speed blower.

What's the Difference in Cost?

Figuring out what to spend on an HVAC system is a major decision for most homeowners. How much will your budget allow for furnaces and air conditioners in a new home or a replacement system? Knowing this could help you decide between a multi-speed or variable speed blower.

How Much Does a Multi-Speed Motor Cost?

A multi-speed blower furnace is the new standard in blowers and will cost less than a variable speed furnace. If your budget won't allow the cost of a variable speed blower and the noise, humidity and air quality levels meet your needs, this is a good choice. Another reason to buy this system is if the electricity rates are lower than average in your area.

How Much Does a Variable Speed Motor Cost?

The "premium" in furnace blower systems is the variable speed. It costs more than single-stage and multi-speed blower systems but gives you a lot for the price. If you want the best - low noise levels, high efficiency, clean air and more humidity control - this should be your choice. The extra benefits may be worth the extra cost.

How to Buy Your System Online and Save has the most affordable furnace systems available online. Our expert customer service team will provide the advice, products and order service you expect. We sell directly to you at wholesale prices and most units are shipped free of charge. Each product is also backed by a generous warranty. Contact us today for assistance the right decision about your HVAC equipment needs.

Variable Speed Furnace Blower Motor Frequently Asked Questions

Is a variable speed blower furnace worth it?

A variable speed blower motor is 80 to 85% more efficient than a regular single-speed motor. While they cost more up front, they often pay for themselves within a few years through energy savings - especially if you are using it as part of a combined furnace/AC central air system.

How does a variable speed furnace blower work?

Unlike traditional blowers that only run at one speed, variable speed furnace blowers can run at a range of speeds. They start at a slow speed and gradually increase or decrease as needed. This gives you more precise control over temperature and airflow while using less energy.

What controls a variable speed furnace?

These furnaces have an ECM motor and speed controller that monitors HVAC system data and automatically makes adjustments. On top of that, the motor can also account for factors such as dirty filters and air quality.

Does a variable speed furnace save money?

Upgrading to a variable speed furnace will save on your energy bills by regulating the amount of fuel spent through your furnace. A variable speed furnace cuts down on wasted gas by providing continuous comfort as opposed to the "on/off" settings of older models. is here for you
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