Heating technology is constantly changing, and as far as comfort goes, for the better. A somewhat popular question today when purchasing a new furnace is whether or not to get a two-stage model. What benefits can be gained with a two-stage model and what does two-stage actually mean?
In the old days the standard furnace was single-stage. Basically this meant the furnace was either on at full capacity or off. With single-stage, the furnace must be sized large enough to keep our home warm when it is very cold outside. Problem is, it isn’t always severely cold out so much of the winter our furnace is too large for our home and begins to cycle on and off. Because of this we encounter a constant temperature swing in our home of around two degrees every cycle.
Two-stage equipment on the other hand can change its output to match how cold it is outside. For instance, on really cold mornings it runs full capacity with the power necessary to recover your home from the night setting and maintain your comfort inside. As the day warms the furnace will automatically slow to an output that matches the daytime temperature. This allows the furnace to closer match your home’s load and efficiently cuts the on-off cycling of an oversized single stage furnace. Essentially it is like having two different sized furnaces in one.
Another important fact is that if your furnace can run longer cycles, your air filter now has the ability to clean the air better because the dust is now moving to the filter more hours per day. With two-stage units, the run time is nearly twice that of a single stage. Humidifiers will also have the ability to keep up with longer run times.
You would think that a two stage furnace would cost more to run because of its longer run cycles. Fact is, any machine is most efficient when it is up and running, not when it is cycling. Think of your car and stop and go driving verses highway. And, don’t worry, even though the two-stage system will run more often, it is running slower so its gas and electricity usage will be much less.
Lastly, two-stage furnaces are quieter. They’re quieter because when running on the low setting we can also slow the air flow through the ducts, saving even more electricity and helping you get a good night’s sleep.