See How Solar Looks On Your Home Read More

Skip navigation

Serving The Greater Fresno Area Since 1970

Serving The Greater Fresno Area Since 1970


Donald P. Dick Air Conditioning Blog

Furnace Types That You Can Consider — Single-Stage, 2- Stage or Variable Speed

Furnace Types That You Can Consider -- Single-Stage, 2- Stage or Variable SpeedWhen you’re considering replacing your existing heating system, it can be difficult to determine what you need. Aside from efficiency levels and heating capacity, furnaces come in different types with regard to how the gas valve and blower motor operates. Knowing your options and understanding the difference between furnace types will help you in making your decision. Before speaking to an HVAC specialist to determine the best fit for your home, you should understand the differences between single-stage, two-stage and variable-speed furnaces.

Single Stage

Single stage furnaces come with a gas valve that only has two settings, closed and open all the way, meaning they only have one heating output, high, at all times. This can lead to higher heating costs due to the amount of energy the furnace takes to run at full speed, even when it doesn’t really need to.

Two Stage

Two-stage (or multi-stage) furnaces are more efficient as their gas valve also has the option of only opening partially. That first stage runs around 65 percent of the level when the valve is open all the way. During periods of extreme cold, the second stage will engage and your furnace will run at 100 percent capacity, similar to how a single-stage furnace runs. Two-stage furnaces provide greater savings because for the great majority of the time, they operate at the lower capacity.

Variable Speed

Variable speed furnaces refer to the fan motor within the system rather than gas valve. The blower motor adjusts its speed according to temperature requirements in your home. Most of the time, they will run at a slower, more continuous speed, providing more even heating, using less energy, and placing less stress on parts. Running at that continuous pace, they also improve air quality in your home by doing a better job of air filtration and humidity control. A variable-speed blower motor is usually paired with a two- or three-stage furnace, offering maximum efficiency. While these systems tend to cost more upfront, over time they also provide the most energy savings.

For more information on the different furnace types or to talk to one of our HVAC experts, contact us at Donald P. Dick Air Conditioning, servicing the greater Fresno area for the last 40 years.

Our goal is to help educate our customers in the greater Fresno, California area about energy and home comfort issues (specific to HVAC systems). For more information about furnace types and other HVAC topics, download our free Home Comfort Resource guide.

Credit/Copyright Attribution: “Stokkete/Shutterstock”

Comments are closed.