Skip navigation

Serving Chester County & Surrounding Areas

Serving Chester County & Surrounding Areas


Service In Hours - Not Days!


Signature HVAC Blog

Putting in a New Heater? You Need Professionals to Size It


It’s no fun to have a heating system give out on you right at the end of the winter. But if you’ve made the choice to replace it now, that’s definitely for the best. Spring is an ideal time to make upgrades to your HVAC system, and it always pays to be proactive about replacing old heating equipment—even if you won’t need it for many months. 

However, if you’re thinking of trying to “go it alone” on the replacement because you think you’ll have the time to do it, well, we’re glad to be here to stop you. A new central heating system installation must be left to trained and licensed technicians. So much can go wrong if an amateur tries the job, starting with incorrectly sizing the unit. 

“Sizing? What is this ‘sizing’ of which you speak?”

It’s not measuring the dimensions of the heating system to see if it will fit (although of course we won’t try to put in a heater that’s too physically big for the available space). The size we’re talking about is how powerful the heating system is. 

For a heater to work effectively for a home, it must hit the “Goldilocks Zone” between oversized and undersized. This is a tricky job, that requires balancing out several factors about…

“Wait a minute. How can a heater be too powerful for a house?”

This is a question people often have, and it’s one of the reasons amateurs make mistakes when sizing a heater. After all, why not err on the side of a heater that’s more powerful? You can always turn it down.

This isn’t how central heating works, however. Too powerful is as bad as not powerful enough for two reasons:

  • An oversized system will shut down early because it heats up the house so fast that the thermostat will incorrectly register that the heater has completed its full cycle and shut it down. This will leave cold spots around the house because the heater didn’t run for long enough.
  • The constant start-and-stop of an oversized heater (known as short-cycling) places immense strain on the components that lead to high energy bills and a system that will wear out years too early.

“Got it. So how do you find the right size?”

Through a process called a heat load calculation. Our technicians take several factors about your house and use them to determine the amount of heating (in tons) a central heater must produce to meet comfort goals without wasting power or short-cycling. The calculation includes the size of the house, the number of windows and their amount of light exposure, the number of people in the house, insulation, the number of heat-producing appliances and lights, and local climate conditions. 

Using this data, we can get an exact idea of how powerful a heater your house needs. For most homes, this will be a heater between 1 to 5 tons. (Tons has nothing to do with weight; it’s a way to measure heating output.)

If you’re ready for a new heater, call an HVAC company in Havertown, PA you can trust: Signature!

Call Signature HVAC for the Signature Service You Can Trust. Serving Chester County & Surrounding Areas.

Comments are closed.

Join Our Mailing List: