Short answer: Yes! There are a great many factors that need to be considered when installing a new furnace in your home, and size is one of them. Far too many homeowners think that if they can physically fit a certain furnace into their homes, then it will operate just fine. This is not true. If you install a furnace that is too large, or too small, then you are setting yourself up for a whole host of problems. Let’s take a look at those problems now.
The reason that size is such a large (haha) consideration when it comes to furnace installation is the heating cycle. The heating cycle is the amount of heat a furnace is designed to put out over a set period of time, in order to heat a certain amount of space. Once the furnace has completed its heating cycle, it will turn off and only activate to make minor adjustments to the temperature.
A furnace that is too large will put out so much heat that the thermostat will shut it off before it can complete its heating cycle. This is called short cycling, and it puts an immense amount of pressure on the system. The added wear and tear will cause the furnace to break down more often, and shorten its overall lifespan.
A furnace that is too small will be forced to stay on for much longer stretches of time than it was designed to, in an effort to heat the home properly. This puts a lot of wear and tear on the system, just like the oversized furnace, and with the same results. The furnace will break down far more often, be less efficient overall, and have to be replaced much sooner.