How to Calculate Furnace Size for a House

How to Calculate Furnace Size for a House

Buying a new furnace is a major decision these days since there is so much choice on the market, including different brands, models and variants, technical capabilities, furnace types, and efficiency ratings. But one of the most essential factors to consider before purchasing a new furnace is the size that is ideal for your home.

Installing a correctly sized furnace is more than just estimating the square footage of your home. When sizing a furnace, there are several factors you need to consider. Now, we’ll review what those aspects are, why it’s essential to properly size a furnace, and how you can buy a furnace that’s the perfect size for your location, environment, and comfort goals.

The goal of this article is to guide you in choosing the required size of furnace for your heating needs. It is calculated by taking the required heating BTU per square foot for most homes and your climate zone. Our heating BTU calculator takes these critical things into consideration, allowing you to give an answer for common questions as “how many BTUs to heat a home?” or “What size furnace do I need?”

The BTU per square foot heating rule of thumb varies greatly depending on your climate and the area of your house or room you wish to heat up.

Why choosing the best Furnace Size Is So Important?

Although it may be tempting to choose a smaller furnace to save money on the purchase price or a larger furnace to boost space-heating, but with furnaces just as with so many things in our lives we should follow the rule of Golden mean: you need one that is just perfect, for your home.

A furnace which is far too powerful will cycle irregularly. This is problematic because it will generate hot and cold zones around the home, decrease efficiency, require additional maintenance, and shorten the furnace’s lifespan.

A furnace which is undersized will operate continuously and won’t be able to maintain a comfortable temperature in your home. The additional workload will also increase your energy costs, cause maintenance issues, and shorten the life of your furnace.

Another drawback of having a furnace that is the incorrect size is that it will reduce your heating system’s overall efficiency.
The AFUE (Annual Fuel Utilization Efficiency) is the thermal efficiency measurement of a furnace based on normal operation. The AFUE tries to represent the equipment’s actual, season-long average efficiency, taking into account all operating factors.

You won’t be able to get the efficiency rating you paid for if your furnace runs continuously or irregularly because it is the wrong size. That means more energy use and higher heating expenses.

Your furnace must be correctly sized for your home in order to perform at the efficiency level it is rated for.

How many BTU do I need for my house?

That is a crucial question that must be answered correctly. On the coldest winter days, a furnace that is way too undersized will not heat your home properly. Areas further away from the furnace may become uncomfortably cold in your home.

An oversized furnace will waste large amounts of energy, and create hot patches around vents close to the furnace before the heating cycle stops.

When you talk about furnace size, you are not talking about the actual physical dimensions of the unit. Rather, the size of a furnace is determined by its heating output and the amount of heat it can provide.

The output of a furnace is often measured in British thermal units (BTU) per hour. A BTU is a unit of measurement for energy, particularly the amount of energy necessary to raise the temperature of one pound of water by one degree Fahrenheit. Heat is now understood to be the same as energy. The joule (J) is the current SI unit for heat and energy; one BTU equals about 1055 J.

Furnace BTU

You need to remember, that “BTU/h” is sometimes abbreviated to just “BTU”. The modern unit of power for heating and cooling systems is the watt. 1000 BTU/h is approximately 293.1 W.

Some manufacturers have started to calculate furnace size in MBHs rather than BTUs. One MBH is 1000 BTU per hour, then you’re still using the same unit: 60 MBH is equal to 60000 BTU.

The general BTU per square foot heating rule of thumb varies from 30 BTU per square foot to 60 BTU per square foot based on your climate zone. That is a significant variation, with one furnace being twice as powerful as the other, so the size factors are explained here to help you in how to size a new furnace for a house.

A bigger furnace, such as one with an output of 120000 BTU per hour, will provide enough heat for a larger space. A smaller furnace will have a smaller BTU capacity, such as 40000 BTU per hour, and would be suitable for only a smaller pace.

Calculating BTU requirements for a house

Let’s start with this very useful map. The climate becomes progressively colder from zone 1 to 3.

Find your location on the map. If you’re on or close the border between two zones, choose the higher number, the cooler zone.

Canada climate zones

Take the square footage of your home. If you don’t know it, you can look up the blueprint of the house, or measure rectangles within your home. Multiply the width by length for each rectangle and add them together.

It is not quite accurate, but nevertheless very useful for our purposes. While you shouldn’t use this calculation to make a final decision about furnace size, you can use it to get an idea of the size range to look at when you buy a new furnace. You can get a basic estimate using the square footage of your house.

The general rule of thumb is that you need between 30 and 60 BTU per square foot. Depending on your climate zone, you can determine how many BTU per square foot you need.

Furnace BTU sizing chart

Square footageFurnace BTU for
Zone 1
Furnace BTU for
Zone 2
Furnace BTU for
Zone 3
100030000 BTU45000 BTU60000 BTU
125037500 BTU56250 BTU75000 BTU
150045000 BTU67500 BTU90000 BTU
200060000 BTU90000 BTU120000 BTU
250075000 BTU112500 BTU150000 BTU
300090000 BTU135000 BTU180000 BTU

Let’s say you live in the Greater Toronto Area (Zone 2), in a home which is 2000 square feet. The chart would tell that you need approximately a 90000 BTU furnace.

These are only examples with approximated values to show how these factors would affect the furnace size you need to buy, how many BTUs needed to heat a house.

Professional furnace sizing

The best way to ensure your furnace is the right size for your home is to get an evaluation from a professional HVAC expert at Furnace Pro.

Furnace Pro Inc. has been proudly providing professional Furnace Installation services to accurately calculate the square footage of your home, factor in all the other elements that can impact furnace size, and give you a precise BTU capacity for your furnace.

Banknotes

How to save money on residential furnaces?

Heating accounts for 61% of your home’s energy use and offers the greatest opportunity for cost savings. Residential furnaces with ENERGY STAR Most Efficient label will save you even more money on your utility bills. Saving energy helps you save money while also lowering your carbon footprint. On average, an ENERGY STAR certified natural gas furnace uses 6% less energy while an ENERGY STAR certified oil furnace uses 9% less energy compared to traditional models.

Rather than cycling on and off repeatedly, high-efficiency blower motors and fans adjust their speed to match your air distribution needs.

Furnaces in Canada can have two labels

  • The ENERGY STAR symbol means the model is highly energy efficient.
  • The EnerGuide label, which is optional, displays the model’s energy consumption and how it compares to similar models.

ENERGY STAR certified products are subjected to rigorous efficiency testing and certification by an independent third party. They perform as well as, if not better, than standard models without sacrificing performance.

We offer the best ENERGY STAR certified furnaces from

The ENERGY STAR name and symbol are trademarks registered in Canada by the United States Environmental Protection Agency and are administered and promoted by Natural Resources Canada.

Quality Furnace Options

Quality Furnace Options: Know Before You Install

While it’s always nice to find a good deal on anything, you should be careful about being too stingy. After all, most quality furnace options are within the same price range, so saving a few bucks shouldn’t be your only focus.

The key word here is quality. Just like you wouldn’t buy a TV from a guy selling them out of his apartment (at least we hope not), you’ll want to go with a brand that is tried and true. There are affordable versions, lesser efficient models, and other half-measures you can take, but having the right heating system in your home can pay off in more ways than you might think.

Lennox & York Are 2 Very Good Quality Furnace Options

As mentioned above, the right heating has many benefits. It can help you save money each month by taking in less energy, heat your home quickly, and have the full backing of an established brand.

Lennox and York are two great options to consider when choosing a new furnace. Both have been around for years and are well-known in the world of HVAC. In fact, you’d be hard-pressed to find a professional technician who couldn’t perform maintenance or repairs on these models.

Each of these quality furnace options has built a reputation for producing quality heating and cooling for people around the globe. They have countless years of experience behind them and are always looking for new ways to deliver a product they can be proud of, which is why Novel Care proudly installs both.

Book Quality Furnace Options With Furnace Pro Inc

For more than 30 years, our team has been installing, maintaining and repairing Lennox and York furnaces in Toronto and the GTA. We do this because each of these brands has done a fantastic job of building quality products that not only last, but are also energy efficient, backed by warranty, and keep our customers happy.

Give us a call at 647-547-6094 to get started with a member of our team. We’ll gladly work with you to establish a consultation to further assess your home’s needs and make recommendations that make sense for you. After all, we’ve been serving this city for more than 35 years ourselves, so we know the value in putting our customers first. Call today and let’s work together to help narrow down your quality furnace options.

improved heating performance

Improved Heating Performance From Your Furnace Or Boiler

Understanding how things work in your home can help you get the most out of them. Don’t worry, this isn’t heating 101 or anything. Instead, this is a list of things you can do to ensure you see an improved heating performance from your furnace or boiler this winter in Toronto and the GTA.

Want Improved Heating Performance? Try These Tips

Even high-efficiency heating systems need a little help sometimes to perform well. Yes, they will still heat your home, but in order to stay true to that “high-efficiency” rating, you’ll need to consider changing up a few things first. After all, if your home isn’t properly insulated, then it doesn’t matter how good your heating system is, you still need improved heating performance.

Windows 101

Besides keeping windows closed – which should be your first priority in the winter –, there are a couple of things you can do to help with drafty windows. The most basic one isn’t pretty though. Insulated window kits are for sale at most hardware or DIY stores, but you could also tape up garbage bags or even bubble wrap to help create a barrier so heat isn’t escaping.

Another tip includes keeping curtains open during the day to allow the sun to add a degree or two. You can also purchase insulated curtains to help your home retain heat at night.  

Stop that draft

Think of this as weatherstripping with less installation. Draft stoppers prevent warm air from escaping through the bottom of any door by blocking it. You can choose to buy one or simply make use of an older blanket by folding it up and laying it across the bottom of your home’s main doors for improved heating performance from your furnace or boiler.

Cooking is king

One of the simplest ways to see improved heating performance is by good ol’ fashioned home cooking. Seriously, if you prepare more food at home, you’ll feel the warmth and give your heating system the help it needs. Not convinced? Think about all those times you said you didn’t want to cook this past summer because it was too warm outside. Make good use of that stove and oven! 

Furnace Pro Inc Can Help With Improved Heating Performance

Not every DIY tip or trick can help make up for any real repairs that are needed. When you need a professional, be sure to call 647-547-6094 anytime. We’re available 24/7 to help in the event of an emergency. Rest assured, our team has been serving Toronto and the GTA for more than 30 years now so there’s nothing we haven’t been able to assess, repair, and install. Give us a call.

Toronto heating options

Toronto Heating Options: Boiler Or Furnace?

When it comes to deciding how to heat your home in a city this big, there are really only 2 main Toronto heating options. Here, we’ll take a closer look at furnaces and boilers to help you know a bit more before investing in the future of your home’s heating.

A Closer Look At Toronto Heating Options For Your Home

Let’s start with the more widely known option of furnaces. A furnace is a great Toronto heating option for a home with existing ductwork. You see, in order for a furnace to operate, it needs to pull in air, heat it up and then distribute that warm air throughout a home via ductwork or vents. Without them already in place, selecting a furnace to heat your home may prove to be quite a bit more expensive than you’d hoped. However, with ductwork in place, furnaces have proven to be a reliable source of heat – often lasting as long as 20+ years if properly maintained.

The other common Toronto heating option would be a boiler. Boilers are usually found in basements of homes and tend to take up quite a bit of room. These systems operate by pulling in water, heating it up to the desired temperature and distributing it to radiators throughout the home. While this is more compatible in just about any home, common issues like kettling, lime scale build-up and the overall amount of space a boiler can take up remind people that these are usually well suited for homes rather than the growing condo population in Toronto and the GTA.

So which one best suits your needs? To be honest, that all comes down to the size of your living space, the type of existing system currently in place, as well as how much maintenance you’d like to perform yourself. Truth is, your best bet is to be honest with yourself and make a list of pros and cons before deciding on one of these Toronto heating options. Just make sure you let a professional handle the installation.

Call Furnace Pro Inc For Help With Toronto Heating Options

For more than 35 years, our team has been available to help homeowners with the installation, maintenance and repair of their heating systems. We’re not about to stop now. Call 647-547-6094 to get started or to learn more about your options based on your needs. Trust us, after 30 years of serving Toronto and the GTA, we know a thing or two about taking care of our customers.

Life Expectancy Of A Furnace

What’s The Life Expectancy Of A Furnace?

Investing in a home is a big step for anyone, especially if you live in Toronto and the GTA. With this city listed among the top 10 most expensive to live in, you’ll want to make sure you get the most from your home’s appliances. Here’s what you need to know about your furnace, including it’s life expectancy, the importance of maintenance, and a few tips to help you get the most out of it.  

Furnace 101 

Every homeowner can expect their furnace to last a minimum of 10-15 years before a new model will need to be installed. However, that doesn’t mean it can’t last longer. In fact, some homeowners have reported their heating system to run for as many as 30 years – which is the absolute maximum number of years.

Increasing The Life Expectancy Of Your Furnace

Furnaces don’t come cheap, so here are a few ways to help your heating system last a bit longer. First off, you’ll want to make sure you schedule regular maintenance (every 1-2 years). While you might be able to search and follow a YouTube video to do this yourself, we recommend leaving this task to the professionals. In our experience, being a novice and attempting to effectively maintain an important – and expensive – heating system like a furnace doesn’t work out well. There is a risk of being hurt as well as doing further damage.

Tips You CAN Do Yourself To Increase The Life Expectancy Of Your Furnace

Making sure all vents are clear and air filters are being changed regularly can help prevent stress on your furnace. Having good airflow is important, which is why using ceiling fans is another useful tip. Ceiling fans help circulate air in a home, allowing your furnace to work less in the winter to heat rooms that might be further away from the unit itself. A few final tips include baking and cooking more often – your stove and oven produce excess heat – , checking for air leaks from doors and windows, and being sure to close the curtains at night all play a positive role in reducing strain on your furnace. These small things all work together with your furnace to help your home stay toasty warm even on the coldest of days. 

Maintenance From Furnace Pro Inc Helps The Life Expectancy Of Your Furnace

Save yourself the stress of having to replace your furnace before its time by giving us a call at 647-547-6094 for some maintenance.  Rest assured, after more than 35 years of serving Toronto and the GTA, our technicians have seen and repaired it all, so we are ready and waiting to help. Call today and let’s add a few more years to the life expectancy of your furnace.

furnace installation in toronto

Furnace Installation In Toronto And The GTA

Finding the right person for any job usually starts with knowing what to look for. Just like with a vehicle, anyone can handle an oil change, but you want to make sure you look around when it comes to steering or brake repair. Same goes for furnace installation. While some professionals claim they can handle the task at hand, you really don’t want to gamble with your home’s heating system.   

Tips For Finding The Right Person For Your Furnace Installation In Toronto

When trying to determine the difference between professional installers, there are 3 areas to consider: experience, area served, and online reviews.

Years of experience with furnace installation in Toronto

There really isn’t a substitute for experience when it comes to furnace installation. After all, if the person you hire has been doing this for years, or represents a company that has a successful track record, chances are you won’t be experiencing any issues. On the other hand, someone new to the field of HVAC or who is a general handyman, might not know how to troubleshoot any issues. Worst case scenario, they make a mess of the job and now you’re paying extra to get a real pro to try and fix everything. 

Parts of Toronto and the GTA served

Another big indicator that you’re dealing with a professional over an amateur is learning how big of a service area they provide. One guy with a truck in Toronto won’t be willing to help if you’re in Brampton, but a larger service might. The bigger the organization, the more resources they have at their disposal to serve customers better. Some even have 24/7 support if you need it.   

Online reviews tell the story

The final indicator of a good furnace installation expert is their online reviews. If they have the experience then you should see plenty of feedback online. Naturally you don’t have to read every word people have written, but skimming through them will give you a better idea of what you’re getting into. Independent furnace installers may be able to fake a couple reviews from their friends, but only those with years of experience will have plenty of real testimonials for your perusal.

For Professional Furnace Installation In Toronto, Call Furnace Pro Inc

Not everyone is looking to do the homework it takes to always find the right person for the right price. But if you’re reading this, chances are you won’t want to gamble with your furnace installation. So if you’re looking for a company with more than 30 years of experience serving Toronto and the GTA, Furnace Pro Inc is ready and waiting. Just call 647-547-6094 today. We’re even available 24/7 in case you ever need us for an emergency repair. Put our team of experienced professionals to work for you, and set your mind at ease.

furnace installation

Always Hire A Professional For Furnace Installation

As a small business owner in Toronto and the GTA, I sincerely recommend hiring a professional to handle any HVAC installation. Late last year I was in a bit of a situation at my office. The heat was never working properly in the winter, but always seemed to get the job done regardless. Just before the holiday break, our furnace gave out completely. We needed furnace installation services fast.

With the holidays only a week and a half away, my upstairs tenant in the building we share recommended his brother-in-law to take a look. It sounded like a good idea at the time, so we gave him a call – assuming this was a furnace installation or HVAC expert. He was not.

Can I Void The Warranty If I Handle The Furnace Installation?

After taking a look and claiming to have fixed the issue, the furnace was producing warm air. The final day before the break I did a walkthrough and noticed the furnace had died. Long story short, I contacted a professional. They weren’t able to come until after the New Year.

Luckily, I saw a Furnace Pro Inc van in my neighbourhood and approached them in person. The technician was nice enough and even took a few minutes to give me a second opinion. He said that the “earlier repairs” weren’t bad enough to void my warranty, but that has happened when dealing with a novice furnace installer.

Furnace Pro Inc Is The Right Choice For Furnace Installation

Toronto and the GTA is a big place, but Furnace Pro Inc is up to the task. When it comes to HVAC issues, don’t hesitate to give them a call. They’re nice, knowledgeable, and efficient. Real professionals. I’d recommend them to anyone looking for help with their furnace. Luckily I was able to avoid the need for a new furnace until the following spring, but when it finally called it quits, I booked Furnace Pro Inc to handle my furnace installation. Now my office is toasty warm, every winter.

Our expert team at Furnace Pro Inc work hard to put our customer first for over 30 years. If you ever have a problem, we can be there to take your call 24/7, and dispatch someone to your home or office within hours. Leave your HVAC to our professionals for a job well done. Give us a call if you need anything at 647-547-6094. We’d be more than happy to help with furnace installation, repairs, maintenance and more.

our old furnace

Case Study: Our Old Furnace

Billy and Jean were sitting in their Toronto home one cold winter weekend last year and all of a sudden they felt a chill. Thinking nothing of it they grabbed a blanket and cuddled up, but the chill only got worse and before they knew it they could see their breath right in their living room. It quickly became obvious that something was wrong with their furnace.

Billy fiddled with the thermostat, but it changed nothing. He went downstairs to “check” the furnace, but he knew he wasn’t an HVAC technician and yelled upstairs to Jean, “our old furnace is just finished I think”.

This isn’t uncommon. They had their furnace since they moved into their renovated Toronto home 15 years ago and haven’t changed it since. Their next step was a smart one, they called Furnace Pro Inc. They knew that it wouldn’t be long before they were dealing with frozen pipes and since they used Furnace Pro Inc for annual maintenance appointments, they knew a Furnace Pro Inc HVAC technician would be at their home to help in no time.

When we arrived we could see that Billy and Jean were cold and that they needed a new furnace. We got on it quickly and by the end of that Saturday they had a new furnace installed in their home.

Overall, Billy and Jean made the right choice knowing that Furnace Pro Inc provides 24/7 emergency services year round, even on the coldest days of winter. We know you don’t want to deal with frozen pipes, which can lead to additional costs and renovations if water ruins your home’s building materials.

If you find yourself in a situation like Billy and Jean worrying about “our old furnace” give us a call, no matter what time of day it is or even if it’s a weekend or a holiday. We’re available all the time to help out. Contact us at 647-547-6094.