Should I Get A Single-Stage, Two-Stage, Or Modulating Furnace?
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Should I Get a Single-Stage, Two-Stage, or Modulating Furnace?


If you’re getting ready to replace your home’s current furnace, the wide selection of brands and models can make the final decision overwhelming. That’s why it always helps to start with the basics: what type of furnace does your home need?

To help you answer this question, we’re going to explain the essential characteristics, pros, and cons of the three most common furnace types for homes: single-stage, two-stage, and modulating. Just keep reading to learn more!

Single-Stage Furnaces

Of the three types of furnaces we’ll be discussing here, a single-stage model is the most basic. As implied by its name, a single-stage furnace has only one “on” setting. Essentially, this furnace type is either not running (turned off) or is running at full power.

Single-Stage Furnace Advantages

The greatest advantage of purchasing a single-stage furnace is its price tag. In terms of upfront cost, this type will be significantly cheaper than a two-stage or modulating furnace.

Single-Stage Furnace Drawbacks

Even though you can save a lot of money upfront by purchasing a single-stage furnace, as opposed to the other two types mentioned here, you might face some long-term disadvantages. In climates where it can get frigid during the winter, a single-stage furnace may struggle to warm up your home both evenly and efficiently, particularly if your home is two or more stories.

Because these furnaces can only run at full-power, they tend to heat up certain areas of your home quickly and then shut off before the rest of your home can achieve the same temperature. This creates hot and cold spots throughout your home. Then, to get rid of the cold spots, many homeowners will turn their thermostat up higher so that their furnace will run longer. This results in a higher energy bill.

Should I Get a Single-Stage Furnace?

If you own a smaller, one-story home, a single-stage furnace might be perfectly suitable to meet your heating needs. The furnace won’t have to compensate for temperature differences between upper and lower floors and therefore has a better chance of heating your home evenly.

It might also be wisest to purchase this simple furnace type if you absolutely must replace your current furnace now but know that you’ll be moving soon. There isn’t much sense in investing in an energy-saving model when you won’t be there to reap the benefits.

Two-Stage Furnaces

Two-stage furnaces come equipped with two separate power modes. They can run at low power or high power, depending on what the situation demands.

Two-Stage Furnace Advantages

Because of its dual power modes, a two-stage furnace can even out hot and cold spots as well as diminish temperature fluctuations in your home. Dramatic hot and cold fluctuations occur more commonly with single-stage furnaces because the unit is either running at full power or not at all. However, because a two-stage furnace can run at a lower power setting, it’s going to allow your home to reach an even temperature before shutting off, and it’s going to do this while expending less energy than a single-stage model.

Two-Stage Furnace Drawbacks

The biggest drawback accompanying a two-stage furnace is its upfront cost. The unit can provide long-term energy savings and improved comfort- -however, this means that you’ll generally spend a few hundred to several hundred dollars more for this furnace type than a single-stage unit.

Should I Get a Two-Stage Furnace?

A two-stage furnace will provide the greatest benefit to you if these statements match your current circumstances:

  • You own a home with two or more stories.

  • You experience uneven temperatures (hot and cold spots) in your home, or you run your furnace an extra long time to eliminate cold spots.

  • You plan to stay in your current residence for the next several years or longer.

Keep in mind that because of a two-stage furnace’s higher price tag, you want to make sure that you’ll be able to enjoy that investment in your comfort and energy savings. If you plan on moving in a year or two, a two-stage furnace might not be worth the upfront cost.

Modulating Furnaces

If you want the most energy savings and the most on-the-dot temperature control a furnace has to offer, consider a modulating furnace. Beyond a two-stage setting, a modulating furnace can have dozens. It accomplishes this by adjusting its flame in slight increments (as little as one percent) to change the amount of heat it puts out.

Frequently you’ll see this furnace type accompanied by a variable-speed blower. Instead of running at just one fan speed, the variable-speed blower adjusts to help your home reach a precise, even temperature without spending excess energy.

Modulating Furnace Advantages

A modulating furnace is the most energy-efficient type you can buy. In other words, they are the most cost-effective when it comes to long-term energy savings. Top-quality modulating furnaces can achieve an incredible AFUE rating of up to 98%: up to 98 cents of one dollar you spend goes toward heating your home. With a rating like that, you’ll notice the difference in your energy bills right away.

Modulating furnaces also offer you more temperature control than single- or two-stage furnaces. Modulating units are designed to keep your home within one to two degrees of your desired temperature. Because of their adjustable heat settings and the variable-speed blower that they usually include, they are also able to reduce hot and cold spots significantly.

Modulating Furnace Drawbacks

Of the three furnace types discussed here, a modulating unit will usually be the most expensive to purchase. If you own a smaller, one-story home, it may not make sense to pay the upfront cost for this furnace type, especially if your current furnace type was able to meet your heating needs during its prime.

Should I Get a Modulating Furnace?

You’re most likely to benefit from purchasing a modulating furnace if you own a home with two or more stories, struggle with hot and cold spots, and spend a lot of money to make your home your desired temperature. Again, this is not a purchase to make if you know you’ll be moving soon. The upfront cost will be steep. However, the lower gas and electric bills and increased comfort in your home can make an investment in a modulating furnace well worthwhile.

Need help choosing the right furnace for your Ann Arbor home? Call Iceberg Heating & Cooling today at 734-375-1119.

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