Did you know there are three basic types of gas furnaces? It helps to know what the different types of furnaces are to decide which one is best for your home. There are many variables to consider when you’re thinking about buying a new furnace. What is the square footage of your home? Is it well insulated? What kind of ductwork do you have? Michigan HVAC Pros is a great resource for learning more about furnaces, how they work and the differences between them.
Before you start searching for the perfect furnace, you should understand how a furnace works. Your furnace is comprised of six elements: an electronics system, an ignitor, a heat exchanger, a gas supply line, an exhaust vent, and a blower. What are the functions of each?
Gas supply line: Carries gas to the ignitor chamber.
Ignitor: Turns fuel into heat, lighting the burner and causing combustion. This process pushes gas to the heat exchanger.
Heat exchanger: Warms up powered by hot gas.
Blower: Pushes air through the heat exchanger and warms your home by traveling through ductwork.
Exhaust vent: Funnels toxic gases outside from heat exchanger through PVC pipes, your chimney, or an exhaust system in your home.
Electronic control board: controls all of the elements above to regulate the temperature, thermostat and timing, so your furnace operates efficiently and smoothly.
Three primary categories of gas furnaces
The three main types of furnaces on the market today are single stage, two stage, and variable speed or modulating. Each stage is defined based on the functions of the gas valve and burner. Here’s a breakdown of these kinds of furnaces:
• Single stage: A single stage style of furnace is a much older, less efficient design. It only features one setting, which runs at full capacity all the time, no matter what the temperature is in your house. A single stage furnace is comprised of one fixed gas valve and one single speed blower motor. This type of furnace only has one setting: on and off. Therefore, since this kind of furnace cycles on and off a lot, the temperature in your home will not be ideal. It will always be too hot or too cold. So, if you set your thermostat to 72, your average home temperature might vary between 68 and 80 degrees. Single stage furnaces are constantly starting and stopping, and they are quite noisy. A single stage furnace prompts higher heating bills, too, because homeowners are required to keep turning the thermostat down frequently. One of the pros of a single stage furnace is cost: it’s likely to cost at least $500 less than other types of furnaces, including double stage. If you live in a small living space or bungalow, a single stage furnace might be adequate enough for your home. If you’re on a fixed income or tight budget, a single stage furnace might be your best option.
• Two-stage: A two-stage furnace features two levels of output: high and low. Usually, this type of furnace stays on the low setting and only switches to high gear during extreme cold weather. A two-stage furnace typically runs at a 60-68 percent capacity while on the lowest setting. Two-stage units keep your home at a comfortable temperature no matter how cold it is outside. There’s a more even, warmer distribution of air plus it’s quieter, too. A two-stage furnace is more efficient than a one-stage unit. Homeowners don’t need to constantly adjust the thermostat, either, as it’s a self-regulating system. Overall, this type of furnace is much more environmentally friendly. A few drawbacks of two-stage furnaces are cost (it’s more technically sophisticated) and they’re not suitable for larger homes unless they have zone heating.
• Variable speed (modulating): Variable or modulating speed furnaces have fan motors that move at variable speeds to distribute air throughout your home. Variable furnaces accommodate the temperature in your house by constantly adjusting the flow of heat depending on need. Variable speed furnace blowers are extremely efficient, using six times less electricity than other blowers. It also promotes a healthier, greener air quality in your home, because even if it is switched to the “off” position, the motor continues to operate, circulating air throughout. Keep in mind that one- and two-stage furnaces only circulate air when they’re in the “on” position. Plus, variable speed furnaces use less consumption, resulting in lower monthly energy bills. And they’re much quieter than one-stage furnaces. Although modulating furnaces are considerably more expensive than the other two types of furnaces, they end up paying for themselves in a short time, because your utility bills will be much lower.
The bottom line
Buying a furnace isn’t as easy as selecting your favorite brand. You should call a licensed and insured HVAC contractor to assess your home so you can choose the one hat will be most efficient for your needs. If you own a small home, a one-stage furnace might be suitable. If you need to heat a larger home, consider a two-stage or variable furnace. A higher initial investment will pay off eventually in the form of energy savings. Call a reputable heating and cooling company today to set up an inspection. They’ll help you choose the right furnace and give you financing options, so you won’t need to worry about budget being a barrier. There are lots of choices out there in terms of furnaces, so be sure to do some research and consult an HVAC expert first.