The Differences Between One-Stage, Two-Stage, and Variable Speed Furnaces

So it’s that time of year again in San Diego—the days are getting shorter and the weather is getting colder—and it’s got you thinking about your furnace that needs replacing.  Maybe you’re happy with the kind of furnace you have now and you just need to install a new one, or maybe you’re looking for a furnace that’s more efficient and will save you money.  In any case, here is some information on the three different types of furnaces that you can get installed in your San Diego home.

One-Stage Furnace

The one-stage furnace does exactly what its name describes: it heats your home using one setting.  This means that no matter how cold or warm it is, your furnace will be functioning at full capacity.  Imagine getting in your car and only being able to drive 0 mph or 75 mph.  That’s pretty much how the one-stage furnace works.  Initially it will cost you less to install a one-stage furnace, but in the long run it may not be the most efficient way to heat your home.  This kind of furnace only works at full blast and expends the maximum energy it is designed to use whenever it’s on. If this is the kind of furnace you’re looking for, great! If not, there are two other kinds of furnaces that will heat your San Diego home to comfort.

Two-Stage Furnace

Unlike the one-stage furnace, the two-stage furnace has (you guessed it!) two different speed settings, low and high.  Your two-stage furnace will run for a longer period of time, but it will be on low for the majority of the time.  This will provide your home will better heat distribution and make sure that there are no cold spots.  When the weather outside gets particularly cold, the high setting will turn on to ensure that your home stays at the perfect temperature.  Because your furnace will not be working at full capacity all the time, it will be much more energy efficient and it will work more quietly, not to mention that it will emit less carbon dioxide into the environment. 

Variable-Speed Furnace

The variable-speed furnace is pretty much the best type of furnace you can get.  You can get a variable-speed speed two-stage furnace.  Its variable speed is a reference to its interior blower motor and how it operates at different speeds.  With this advanced technology, the furnace will be able to control the heated air flowing into your home more accurately.  It does this by monitoring and adjusting its blower settings to account for things such as your duct work, furnace location, and dirty filters, which are all things that can restrict airflow.  What a machine!

Because a variable-speed furnace is able to constantly adjust its blower motor, your furnace will be running more efficiently than a one-stage or two-stage furnace without variable-speed.  Even when your furnace isn't on, its motor will be continually running ensuring greater air circulation.  As the air continues to circulate, the air in your home will constantly be going through the filter.  This means that the air in your home will be healthier and of better quality, since it will be rid of bacteria, viruses, mold spores, and other contaminants through the filter.  Need I say again, “What a machine!”?


So we hope you've been informed by our little spiel on the different kinds of furnaces you can get.  If you have any further questions on which kind of furnace will work best for your San Diego home, feel free to ask!  We’re here to serve you!