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Single-Stage, Two-Stage and Modulating Furnaces

Regardless if you are replacing just a furnace or a full system, you need to make sure your entire system is compatible with both the outdoor and the indoor unit. In this video, we will compare single-stage, two-stage and variable speed furnaces and show you the benefits that each stage has to offer.

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January 12th, 2021

Jared: So, let's say you're an individual that's looking to replace your current heating system. And when you're shopping around, you come across something that says single-stage to stage or modulating furnaces. In this video, we'll talk about the differences of these stages and which stage might be right for you.

Hi, I'm Jared from Fire &  Ice. And regardless, if you're replacing the furnace or the full system, you need to make sure that your system is compatible with both the outdoor and the indoor unit. In this video, we'll sit down with Roger Bakies, Residential Sales Professional for Fire & Ice. And in this video, we'll cover, what's the difference between a single-stage to stage and modulating furnaces? What are the benefits of each stage? What's an example of a product in each stage? Who would be the right fit for each type of stage? And finally, what to do next. We hope by the end of this video, you'll know the difference between single-stage, two-stage and modulating furnaces and which stage is right for you.

What is a single-stage furnace?

So, Roger, let's jump right in and go over what's a single-stage furnace?

Roger: A single-stage furnace is the most basic furnace available. It is basically on or off. And of course, you need more BTUs of heat or more heat to heat your home in the coldest weather than you do in mild weather. The single-stage refers to the function of the gas valve, and of course, the function of the blower that that works with it. The benefit of the single-stage furnace is primarily going to be the price point. It's going to be the most reasonable price point. And of course, the fact that it does provide more than adequate comfort for the average homeowner.

The downside to the single-stage furnaces are going to be temperature swings. Obviously, in the mild weather we come on at 100% spike past the furnace set point. It turns off. The temperature falls below the set point. And we can get temperature swings of two even three degrees.

The average cost of a single-stage furnace is going to start out around $3,900. An example of a single-stage furnace is a Trane S9X1. That is their S-series furnace with a stainless steel primary and secondary heat exchanger. Individuals that would be a good fit for this furnace would be someone who possibly doesn't plan to be in their home for a long time. Possibly it's going to be a rental. Or they just want a good, solid, basic system at a more reasonable price.

What’s a two-stage furnace?

Jared: Hey, that's great, Roger. Now let's cover what's a two-stage furnace?

Roger: A two-stage furnace is a machine that's going to operate at two different capacities. So it's really like having two furnaces and one. In mild weather, it's going to function at 60% of its capacity. And then when it gets real cold out, it's going to go to 100% of its capacity.

The benefits of the two-stage furnace are, of course, the operation would be at 60% or 100%. So, it's going to be a longer run time. More even heat distribution. And of course, more comfort to the homeowner. The only downside of a two-stage machine is going to be the additional cost. And of course, if you choose a model without the variable speed blower, you don't get the enhanced dehumidification and the additional electrical savings, as well as a slightly better temperature control.

The cost of a two-stage furnace starts out at around $5,200. And of course that's a starting cost. Your particular installation parameters, size of the machine, location, and these types of things will affect the price as well. An example of a two-stage furnace would be the carrier performance line. 96% efficient with the two-stage operation. A solid piece of machinery.

We find people that are a good fit for the two-stage furnace to be homeowners that may plan on staying in their home longer. And of course, this is going to be a good fit between the very top of the line and the basic. Puts you in the middle. Better comfort at a reasonable price.

What’s a modulating furnace?

Jared: And finally, Roger, let's talk about what's a modulating furnace.

Roger: A modulating gas furnace is a machine that's going to operate from 40% to 100% in possibly 1% increments. This is going to be a fully communicating machine, and it is going to track that temperature and adjust itself up or down in real time to try to maintain the very most accurate temperature control in the house within one degree. And of course, its operation is only ever going to provide enough heat that is needed at that moment, not cycling and wasting gas. This is the ultimate comfort system and the best you can get in forced air heating.

Really, the only downside to a modulating gas furnace is going to be a higher initial investment in the piece of machinery. The average cost of a modulating gas furnace is going to start out around $6,300, and that cost is a starting point. Your particular installation parameters, as well as the size of the machine, are going to affect that cost. An example of the modulating gas furnace would be the Trane XC95m. One of the highest quality machines on the market.

And it's going to provide you with the ultimate comfort we find homeowners to be a good fit for this machine. That plan to be in their home long term. Don't mind a higher initial investment cost for the benefits and features it provides and what the ultimate control of the comfort of their home.

What are the next steps?

Jared: Hey, thanks, Roger. So now that you know a difference between single-stage, two-stage and modulating furnaces. Visit our product page and see a complete list of comfort and efficiency ratings for each product that we have to offer. Thank you for watching and we're looking forward to making your day better.

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