Our Top Priority is Customer Service
Call for Emergency +1 (289) 778-5661
factors to consider when sizing furnace

Purchasing a new furnace may seem intimidating, but it’s necessary for today’s climate. Winter is fast approaching, and the average homeowner must choose the right size furnace to manage energy costs. This article will go over how to size a furnace by square footage and AFUE. And we’ll also cover how to calculate furnace size with insulation. If you haven’t done this before, you’re missing much information.

Calculating furnace size by square footage

Before buying a furnace, you must know how many square feet your home has. You can figure out the square footage of your house by multiplying the length and width of each room. If your house is irregularly shaped, you may need to take measurements for each room. Your home might have square footage that isn’t listed anywhere in some cases. If you’re unsure, call a furnace installation technician to do the measurement for you.

The number of floors in your home will affect the BTUs required by your furnace. A 1,000-square-foot home with just one level will need a furnace with a BTU rating of 110,000 or higher. However, a second-floor home will have insulation on both floors, lowering its heating needs. Additionally, open concept homes have fewer interior walls to hold heat, which will require a larger furnace. Certain features of the house will also make heat leakage easier.

Another way to determine the amount of heat needed by your home is by examining the BTU rating of the existing furnace. Many manufacturers rate their furnaces in British Thermal Units (BTU). A furnace rated at 90,000 BTUs is the most effective for homes that are 2,000 square feet and have a climate zone of F6. Alternatively, you can consult the manufacturer’s website to determine the capacity of the furnace.

Many other factors can influence the BTUs of a furnace. The climate and the size of your home will be the most significant ones. Larger homes need a larger furnace because of the additional heat. To determine the amount of heat you need, use a calculator that shows the number of BTUs of different home sizes. If your home is 2,500 square feet, you need a furnace that produces between 100,000 and 112,500 BTUs.

Despite these factors, you can also take the help of an HVAC expert to estimate the size of your home. The HVAC expert will consider the insulation, window size, and duct sizes to determine the size of the right furnace for your home. Then, you can proceed to choose the furnace. 

Calculating furnace size by AFUE

The first thing to remember when calculating furnace size by AFUE is the square footage of your house. Find the square footage on your home’s blueprint or closing documents. If you don’t have this information, measure each floor by the width and length of a rectangle. Then multiply the totals to get the total square footage of your home. This calculation will help you determine the size of your furnace.

Older homes often have low AFUE ratings. The Department of Energy considers units with ratings of between 56 and 70 percent as old and outdated. An outdated heating system means you will pay more money to heat your home every month. Mid-level efficiency systems will typically be smaller than earlier models. They may also be more efficient because they have a variable-speed blower. This type of furnace can also include an exhaust fan.

Another thing to consider when determining furnace size is the BTU of the furnace. A furnace with a BTU of 70,000 has a higher input capacity due to the loss of heat during the heating process. A furnace with a lower output BTU will not have a high AFUE, and the output will be smaller. For those who don’t want to spend extra money, a 7,000-BTU furnace may be all they need.

Choosing the right size furnace can be a complicated process. An experienced HVAC company like Furnace Repair Hamilton can help you with this process by thoroughly analyzing your home. An HVAC professional can determine your home’s BTU requirement and recommend the best furnace to match it. In addition, they will analyze ductwork, insulation, window size, and ceiling height. 

Another factor to consider when determining the right furnace size is your area’s climate. A larger house will require a bigger furnace than a smaller one. Make sure to know the approximate square footage of all the heated areas in your home before buying a new one. This way, you won’t need to waste your money on a furnace that won’t work. 

Insulation factored in

How is insulation factored in when sizing a furnace? Typically, the average house needs about thirty to sixty BTUs per square foot of heat. However, the amount of heat a home needs can vary depending on climate zone, insulation, and age. Many homeowners don’t replace their furnaces for years, so choosing the right furnace for your house is essential. The right-sized heating system lowers your heating bill and improves the home’s overall efficiency.

If you are unsure about the square footage of your home, you can consult your closing documents or blueprints to get an accurate measurement. If you can’t get hold of these documents, measure each room’s length and width and add them together. The square footage of each room should be within the parameters of your furnace sizing calculator. After you’ve determined the square footage of each room, you can choose the size of your new furnace.

A well-insulated home can save money on energy bills. Using thicker insulation can significantly increase your home’s energy efficiency. Insulation should be in the walls, attic, basement, and crawlspace. In older homes, windows and skylights can leak, so it’s essential to consider them when sizing your furnace. Consult a contractor if you’re not sure how much insulation you need.

Learning Resources

Our Latest News

The best guidelines and tech news in the industry of the Heating and Cooling service world.

Please take advantage of our blog posts that answer your questions and help you learn about our services.