It’s a relatively cold winter after an exceptionally hot summer. Many of us are eager to stay toasty when temperatures drop. Unfortunately, a nice, warm home often comes with a hefty energy bill — especially if you’re using a traditional gas furnace. Modern modulating furnaces could be a solution as they tend to be more energy-efficient. But is it the right choice for your property?

How Does a Modulating Furnace Work?

As the name suggests, a modulating furnace adjusts the heat depending on your needs.

Modulating furnaces feature a variable-speed blower to better control when the furnace turns on and off. The fan speed adjusts to reflect the current thermostat setting, helping distribute heat evenly throughout your home. As a bonus, this can help prevent your indoor air quality from feeling stuffy when the furnace kicks on.

There’s also a gas valve that actually adjusts the gas level and therefore the intensity of the flame. It’s highly sensitive so your furnace only uses as much energy as needed to slightly raise or lower the heat. Unlike a traditional furnace, a modulating furnace can adjust its power level in increments as small as 1 percent!

Another neat feature is the secondary heat exchanger, which captures any residual heat from the primary combustion. This, too, saves on fuel costs by maximizing your furnace’s use of gas. Modulating furnaces can use up to 95 percent of the fuel they consume, compared to just 85 percent for standard furnaces.

How Modulating Furnace Work

Modulating Furnaces vs. Single-Stage Furnaces

By contrast, a classic furnace, also called a single-stage furnace, is either on or off. That can be a problem if it’s just chilly enough to turn on the heat but you don’t want to start sweating in your own home.

Also, if you have ductwork issues or variable insulation, the temperature can become widely inconsistent from room to room. Yet the furnace will still kick on, depending on where the thermostat is located.

Worse, gas furnaces are quite energy-intensive, which means they can run up your energy usage merely to heat your home a few degrees. You may find yourself spending money to run the furnace when it’s not even necessary.

Some modern furnaces are two-stage, meaning they have a high and low setting. While these can help avoid excessive energy usage, they’re not as sensitive as modulating furnaces. Plus, you may still experience “hot spots” throughout your house as the heat isn’t distributed as evenly.

Before you call a furnace repair service, consider changing your furnace type.

Should You Invest in a Modulating Furnace?

A modulating furnace certainly sounds ideal, but many homeowners balk at the price. These systems are expensive to install even if they cost much less to operate.

That said, it’s worth considering how much you spend on your annual heating bill, especially if you live in a cold region or your home has duct/insulation issues. The initial expense is often well worth the significant energy savings.

However, if your home is more than 40 years old, a modulating furnace may not work as well, simply because the home is already designed to work with a single- or two-stage furnace. If you’ve maintained your insulation, older homes tend to retain heat fairly well.

On the flip side, modern homes with poor air circulation can benefit immensely from modulating furnaces. These homes often feature better insulation, but more room divisions and larger windows can lead to hot spots. A modulating furnace keeps every room evenly toasty. For that reason, they’re especially popular for multi-story homes, where upper floors tend to get disproportionately warm.

Wrapping Up: Which to Choose?

For most homeowners with houses built within the last few decades, a modulating furnace is an excellent way to reduce heating bills and improve the home’s comfort. Older homes may benefit too, depending on their setup and geographic region. In short, it’s well worth your consideration if you’d like your home to be more energy-efficient — even on the coldest winter night!

Inquire with your local furnace repair and installation service to see if a modulating furnace is right for your property.


James Smith

As you can tell from our humble beginnings in 1981, we began as a family-owned business and stayed a locally owned air conditioning and heating company in Los Angeles county for nearly 40 years.