What Size Furnace Should You Have in Your Home?

Most people don’t realize that furnace size is a lot like shoe size — get the wrong one, and you’ll be uncomfortable the entire time you’re using it. Having your furnace sized correctly will make a huge difference in how comfortable your home is, not to mention your energy bill and the lifespan of your equipment.

Determining Furnace Size

How do you know what size furnace you should get? Well, that depends on a lot of factors, including your home’s location, age, design, insulation and even roofing. Unfortunately, most companies don’t know how to calculate all of these factors correctly — they just guess. Other companies charge a boatload to perform a personalized calculation (what’s called a “load calculation”).

Don’t let someone guess, and don’t overpay — call Ross to get an expert opinion. We’ve been working in HVAC for over 20 years, and we’ll make sure the furnace you get is the furnace you need, without unnecessary overhead or maintenance fees.

Want an inside look? Here are some of the key factors we consider when determining the right size furnace for your home:

1. Square Footage

The square footage of your home is the first step in determining the size of furnace that you’ll need. We want to have an accurate starting number, so it’s important to calculate this carefully, especially if you have any circular or angular rooms. We’ll also need to consider whether your air ducts go into every room — or floor — or if there are any areas that they miss.

2. Climate

The climate you live in determines how hard your furnace will need to work in order to heat your home in your specific geographic area. Unfortunately, Reno-Tahoe is smack dab in the middle of where a few different climate regions come together. That means your exact location will determine what heating factor (measured in BTUs, or British thermal units) we’ll need to multiply by your square footage.

3. Insulation

Once we’ve determined your climate, it’s time to evaluate your home’s insulation. There are a lot of variables that will impact the right size furnace for your home, including:

  • How new it is
  • How well-insulated it is
  • The number of floors
  • The shape of the layout
  • The number of “comfort zones” you want
  • How high the ceilings are
  • How shaded or exposed your home is to sunlight and the elements
  • The number of windows it has
  • What type of windows it has (including how old they are and how well they insulate)
  • Where the windows are located
  • What color your roof is
  • The condition your ductwork is in
  • What your ideal temperature is
  • How many people live there

We take all of these factors into account, and then we modify the climate heating factor that we calculated above so that we’re even more precise.

4. Furnace Efficiency

The exact model of furnace we’re looking at installing will also affect our decision, because furnaces all have different levels of efficiency. Furnaces range from 78% – 100% in their efficiency ratings, which has a significant impact on how many BTUs you can lose in spite of a furnace’s size. Furnaces also decrease in efficiency somewhat as they’re used and as they age.

Ultimately, there’s a lot of detail and nuance involved in calculating the appropriate furnace size for your home. Don’t leave your comfort — and investment — up to chance. Call Ross, and we’ll make sure you don’t overspend and get exactly what you need.

Get in touch

Need help with your heating, air conditioning, water heater or air quality? Give us a call — we’re happy to help!