WHAT SIZE FURNACE DO I NEED? A COLUMBUS HOMEOWNERS’ GUIDE
“What size furnace do I need?” is a question that stumps many homeowners in Ohio. Since the wrong size can waste your money or fail to heat your home properly, it’s a detail you don’t want to get wrong.
The right furnace size depends on factors such as BTU outputs, the square footage of your home, and your city’s climate. You may even have to take into account your window placement and average sun exposure. If you need a little help getting started, Columbus Worthington Air has your back.
We’ve been helping Columbus homeowners enjoy energy-efficient furnace installations and repairs since 1936. Our skilled team provides local expertise and hands-on experience to ensure your unit is always in peak condition. With the help of our in-depth furnace sizing guide, you can start putting together the ideal specs for a new furnace.
Low on time? Contact our team of technicians today, and we’ll narrow down the best furnace for your home.
Quick Answer: What Size Furnace Do I Need?
Determining the right size starts with a unique measuring system called BTU (or British Thermal Unit). This measurement system determines how much heat your system removes within an hour. Additionally, there’s an even more specific measurement system called the Manual J.
Heating professionals rely on the Manual J heat-loss calculation to help them determine both heat retention and heat loss in each part of the house. This reference includes details such as air sealing, windows, and sun exposure, all of which will eventually affect your furnace’s performance.
Since Ohio is no stranger to cold and rainy winters, using every measurement system at your disposal will give you the best picture of what you’re up against.
Prefer a precise number? Schedule a sizing visit with Columbus Worthington Air, and we’ll handle everything for you.
Sizing Basics: Output vs. Input BTU and AFUE
When purchasing a furnace, you’ll notice each unit is graded by its input and output BTU. The input BTU refers to the amount of fuel your furnace consumes within an hour, while the output refers to how much heat enters your home.
AFUE (or Annual Fuel Utilization Efficiency) is another helpful metric that determines how well your furnace converts fuel into heat. A furnace that burns up a lot of fuel, but struggles to keep your house warm, usually points to a problem like age or incompatible sizing.
For example, a furnace that’s labeled with an efficiency of 80% means it’ll produce 80,000 BTUs of heat. Another furnace labeled with 90% will produce 90,000 BTUs.
If you’re thinking bigger automatically equals better, it’s important to note that too much heat may actually harm your furnace’s performance. We’ll take a look at the science behind this in the following sections.
Not sure if you need furnace repair or furnace replacement? Take a look at our furnace services to see which visit could get your unit back into peak working condition.
The 5 Main Factors Impacting Your Home’s Furnace Needs
Choosing the right furnace size means going through your home and tallying up details that could improve (or hurt) your unit’s performance. With these main factors, you’ll be that much closer to a furnace that saves you money and keeps you warm during a bitter Columbus winter.
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Columbus Climate & Your Home’s Heat Loss
Central Ohio sees persistent below‑freezing periods as low as 18 degrees Fahrenheit. It’s better to be safe than sorry, so consider a furnace that can hold up to the most extreme temperatures.
Alongside reviewing your region’s climate, you should take a look at your home’s most common areas of heat loss. For starters, older homes tend to struggle with air leakage around windows, doors, and attics. Newer homes tend to fare better, but may still need special attention devoted to analyzing garage rooms or recently renovated basements.
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Square Footage & Layout
“What size furnace do I need when it comes to square footage?” is another question homeowners ask and for good reason. A furnace that’s too small won’t heat your home well, while a furnace that’s too big may wear out prematurely.
Square footage takes into account the depth, width, and height of a given area. If you have a multistory layout, you should also take into account open stairwells and long duct runs where heat can travel.
When you reach out to a professional, you may need additional features like zoning to improve each room’s heating performance.
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Insulation, Air Sealing & Window Performance
If you’ve spotted air leaks, they’re one of the first areas you should improve before getting a new furnace. Too many air leaks will sap your heating, resulting in a furnace that works too hard and energy bills that are far too high.
We touched on air leakage above, but what can you actually do to correct this issue? Drafty homes with single-pane windows (or old windows in general) may benefit from a brand new window replacement. The money you save over time will eventually pay for the upfront cost.
If you want to save money in the short term, you can also try installing waterproof weatherstrips during the cold season.
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Sun Exposure & Orientation
When it comes to getting a new furnace, you should work smarter, not harder. Consider the placement of your home, its rooms, and windows so you can take advantage of solar heat during the cold season.
For starters, south and west-facing rooms often get more solar heat on sunny days, while north-facing rooms or shaded rooms receive less.
You should also review your home’s exterior setup. Trees, nearby buildings, and overhangs shield you from frigid winds and help your home stay warm.
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Ductwork Condition & Airflow
“What size furnace do I need, and will it affect my ductwork?” is a question that can have you dreading a new installation. However, reviewing your ductwork could be just what you need for a comfortable and energy-efficient home.
Leaky, undersized, and restrictive ducts will impact your furnace’s airflow, making it harder for it to distribute heat throughout the home. When you call a professional, they’ll review your ducts’ return air and supply balance to address any possible issues.
What Happens If the Furnace Is Oversized?
An oversized furnace sounds good on paper, but it actually becomes worn out in a too-small home. It faces frequent cycling issues due to warming up the home far too quickly.
As a result, your unit’s internal parts will become more worn out in a shorter amount of time. It can also exhibit more noise, to boot.
What Happens If the Furnace Is Undersized?
An undersized furnace may seem like a more affordable option, but it can also cost you in the long run. Furnaces that are a little too small will struggle to reach the ideal temperature point on very cold days, leaving you cold while running longer and harder.
This issue means your furnace will also become worn out prematurely, leading to more frequent maintenance and tune-ups.
What Size Furnace Do I Need? Get A Professional Opinion
When in doubt, get a professional on the case. Columbus Worthington Air has been a trusted local resource for Ohio homeowners who need a second pair of eyes on their home’s heating needs.
We take a look at historic homes and modern homes alike to measure airflow, spot air leaks, and suggest areas of improvement. Alongside helping you choose the right furnace size and model, our experienced team can provide ductwork maintenance, install smart thermostats, and help with zoning.
Whatever you need to keep your home warm during a frigid Ohio winter, we’re ready to help.
Columbus Worthington Air Will Pick the Right Furnace Size
If analyzing all these details is a little overwhelming, don’t worry. Our technicians are ready to help you install a new furnace in your home so you can stay warm and save money.
Schedule service with Columbus Worthington Air with our simple online form to get a professional sizing assessment. We can’t wait to meet you!