What’s Best? Single Stage, Two Stage or Modulating Furnace?

Great, you’re searching for a new furnace and you understand that each furnace is different. But you’re not really sure how, other than the fact that each is described differently by the manufacturer.

There is a bunch of jargon you don’t really get, and shouldn’t get. If you haven’t purchased a furnace in the last decade and you don’t work in this industry, there’s no reason you should be familiar with the terminology. But now that you’re buying, you need to be.

The most important jargon probably revolves around:

  • Single stage.
  • Two stage.
  • Modulating furnaces.

Your single stage option

A single stage furnace has two settings.

The thermostat in the house tells the furnace it’s too cold, so the furnace powers up. It turns on to the one setting it has, 100%. It runs at full power until the thermostat is satisfied, then shut itself off.

The system cycles like this several times through the day, and you might notice somewhat uneven heat throughout the house. Heat comes in bursts and dissipates at different rates throughout the house, so the far reaches of the house won’t be as comfortable as the more central area

A single stage furnace is your most affordable option.

Your two stage option

A two stage furnace can run at two different levels. Each is different, but generally we can say they have a 60% setting and a 100% setting.

A two stage furnace is quieter and generates less sporadic heat throughout your house. The longer, slower heating cycle where the furnace runs at 60% (or so) eliminates the kind of rapid warming and cooling many people find uncomfortable from a single stage furnace.

The longer cycle also results in superior air filtration, because the air cycles through the furnace air filter more times in a day. Air quality is significantly improved in the house if you complement your furnace with a humidifier.

A two stage furnace strikes the best balance between cost and value – more expensive to purchase than a single stage, but quieter and more efficient.

Your modulating furnace

Modulating furnaces run in very precise increments. Some models can run at 40% capacity on the low end and step up by .5% if the thermostat calls for it, all the way to 100% capacity. Because this type of furnace manages temperature so acutely, they usually run continuously at a very low setting. Silent and steady.

The temperature in every room of the house remains consistent because of this continuous operation.

Modulating furnaces can achieve up to 98% efficiency, meaning 98% of the fuel fed to the system returns as heat. As the most efficient and highest performing furnace design, they’re the most expensive to purchase.

Make your choice!

There’s a long and uninteresting formula to determine the best furnace for your family. We can boil it down to this:

  • If you plan to stay in your current home more than 5 years, invest in the modulating furnace. It will pay for itself through savings in around 3.5-5 years, then you’ll have 15 more years or more of ongoing heating savings.
  • If you are unsure, the two stage is a good balance of value to investment.
  • If you are flipping a house or plan to move imminently, a single stage will do the job.

Get in touch with a member of our team to learn about the high efficiency furnace options. You won’t regret it!