Different Types of Furnaces: What You Need to Know

If your house furnace is growing old, or you just want to save money on your energy bills this winter, it’s crucial to understand the different types of forced air furnaces. There are several distinct types of furnaces, each with its own set of advantages that you should be aware of.

​Differences Between Furnaces

There are a few key distinctions between furnaces and how they work. The first distinction is the method through which the furnaces generate heat. Some do it in one step to generate as much heat as possible, while others do it in two steps to have greater control over the amount of heat they produce. The second major distinction between furnaces is how their blowers work. The blower is responsible for distributing the heat generated throughout your home. The blowers on some furnaces run at full speed all of the time. Others operate their blowers at different speeds, which has an impact on comfort and efficiency while in use.

Which is Better: Single-Phase or Two-Phase Furnaces?

​Older furnaces are all single phase, which means they produce heat at full capacity all of the time. This isn’t always a bad thing because it lowers the cost of the furnaces. However, if you value economy and comfort, a single phase furnace isn’t the ideal choice. Two-stage furnaces are noted for being more efficient, with AFUE (annual fuel usage efficiency) values often exceeding 95 percent. Single phase units, on the other hand, typically have AFUE levels in the 80s.

Because of how these two types of furnaces work, there is a significant efficiency gap between them. After going through the warm-up process and functioning for longer periods of time, furnaces are at their most efficient. As a result, an oversized furnace is always less efficient than one that is correctly sized. A single-phase furnace turns on, warms your house, and then turns off. During the coolest part of the day, a two phase furnace turns on at full power to warm your home. It does not turn off after your home is warm; instead, it reduces the heat output to a low level and continues to run and try to keep heat levels within a degree or two of the thermostat’s settings. A two-phase furnace operates economically by operating continuously, and it simply cycles between high and low heat output levels to keep your home at appropriate temperatures.

Models with Variable Speed vs. Standard Furnaces

​Some furnaces use constant-power blowers. The furnaces in this picture are standard. Others use a blower that accelerates and decelerates depending on how hot your home needs to be. If the house only requires a minor boost in warmth, the blower can be set to run at a lesser speed, saving energy and creating a more comfortable environment. Not only that, but this type of blower has been proved to have a longer operating life and should be able to keep your home at a pleasant temperature for years longer than a standard single-speed blower. A variable-speed blower can precisely supply the proper quantity of heat and is frequently used in conjunction with a two-stage furnace to achieve maximum efficiency.

Single-stage furnaces are less efficient than two-stage furnaces, and furnaces with variable-speed blowers are even more efficient. These more modern and efficient furnaces are a little more expensive up front, but they should make up for it with increased efficiency and a more comfortable environment over the course of their lifetime, making them a worthy investment to consider.

If you want to understand more about furnace, Call us at: (720) 320-3531