If you’re on the market looking for a new furnace, you’ve probably come across the term AFUE. Annual Fuel Utilization Efficiency (AFUE) is an abbreviation for Annual Fuel Utilization Efficiency. The annual fuel utilization efficiency (AFUE) of a gas furnace is a measure of its efficiency in converting fuel to energy. The higher the AFUE rating, the more energy efficient the system. Many homeowners are confused about what the AFUE rating means, what they should look for in a new heating system, and how this value compares to others.

What is AFUE?

The AFUE rating of a furnace measures its gas efficiency over the course of a heating season. The AFUE, which is represented as a percentage, reveals the precise quantity of heat generated for each fuel dollar used; the greater the percentage, the more efficient the heating unit.

A furnace with a 90 percent AFUE, for example, indicates that throughout the course of the winter, 90 percent of the fuel utilized was turned into heat and just 10% was lost. Older furnaces have an average AFUE of 60%, but contemporary, high-efficiency furnaces can have an AFUE close to 99%.

As an example, take a furnace with a % AFUE rating. In this scenario, a 95 percent rating means that 95 percent of the gas used by the furnace is converted to heat, while the remaining 5% is lost in the exhaust.

As an example, take a furnace with a % AFUE rating. In this scenario, a 95 percent rating means that 95 percent of the gas used by the furnace is converted to heat, while the remaining 5% is lost in the exhaust.

Or, to put it another perspective, for every $1 spent on heating in your house, 95 cents are used to heat your home, while the remaining 5 cents are wasted.

What is the Best for your home?

The higher the AFUE, the more money you’ll save on heating expenses each month. You’ll save even more money each month as gas prices rise. For these reasons, you’ll want to invest in the most energy-efficient heating system you can afford.

A new high-efficiency furnace will be more reliable than an older model, in addition to saving money each month. New furnaces normally come with a 10-year parts guarantee, but older units have a 5-year parts warranty. This will provide you piece of mind knowing that if your furnace requires a replacement part, the part will be free of charge for the first ten years. You may also add an extended labour warranty to your new furnace to provide complete coverage for both parts and labour.

Your AFUE allows you to compare the efficiency of several furnace types, guiding you in making the best decision for your home. However keep in mind that the AFUE rating is only one component of the equation.  You must also assess that you have the proper furnace size. We want to make this process as simple as possible for you, and help to calculate the correct size for your new system.

At Tankless Pro, we only offer high efficiency furnaces and the best service. We have a number of different models to fit most budgets and you can use a sizing chart to ensure that the right equipment is used in your home.

Purchasing a brand new furnace is a serious decision these days because there are so many options, including different brands, models, and variations, technical capabilities, furnace types, and efficiency ratings. However, one of the most important factors to consider when choosing a new furnace is the size that is best suitable for your home in Toronto.

A Building Permit from Toronto Town Hall is usually not required for furnace replacement if no building alterations are taking place.

Installing a properly sized furnace requires more than simply calculating your home’s square footage. There are various aspects to consider while sizing a new gas furnace. Now we’ll go over what those factors are, why properly sizing a furnace is so important, and how to find a furnace that’s the right size for your location, environment, and comfort needs.

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. Toronto is located in Zone 2.

Why choosing the best Furnace Size Is So Important?

While it may be appealing to choose a smaller furnace to save money on the purchase or a larger furnace to increase space-heating, we should follow the Golden Mean rule with furnaces, just as we should with many aspects in our lives: you need one that is just right 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 house, decrease efficiency, require additional maintenance, and shorten the life of the furnace.

An undersized furnace will operate non-stop and won’t keep the temperature in your home at comfortable levels. The additional workload will also increase your energy bills, inrease the probability of maintenance issues, and also shorten the lifespan of your heating unit.

Another drawback of having a furnace that is the incorrectly sized is that it will reduce the overall efficiency of your heating system.
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 in Toronto?

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 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 footage Furnace BTU for
Zone 1
Furnace BTU for
Zone 2
Furnace BTU for
Zone 3
1000 30000 BTU 45000 BTU 60000 BTU
1250 37500 BTU 56250 BTU 75000 BTU
1500 45000 BTU 67500 BTU 90000 BTU
2000 60000 BTU 90000 BTU 120000 BTU
2500 75000 BTU 112500 BTU 150000 BTU
3000 90000 BTU 135000 BTU 180000 BTU

Living in Toronto, Ontario (Zone 2), in a home which is 2000 square feet. The chart would tell that you probably need a 90000 BTU furnace.

This value is only a rough approximation to demonstrate how these previously mentioned factors can affect the furnace size you need to buy, how many BTUs needed to heat a house. There are several additional factors that can affect the final furnace sizing calculation.

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 Tankless Pro.

Tankless Pro 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.

As professional HVAC installers and technicians in Toronto and the GTA, we have some experience with Lennox. Here’s what you need to know about their air conditioners and furnace options.

Lennox Offers Residential And Commercial Options

Whether you’re a homeowner or business owner, Lennox has a series of models that make sense for your needs. Best of all, their furnaces and air conditioners are designed with high efficiency, minimal noise, and longevity in mind. Simply put, Lennox is a good investment, as long as you have a professional handle the installation and maintenance.

Safety Is A Big Priority At Lennox

You don’t last since 1985 without taking care of your customers. That’s why Lennox has a number of safety measures in place to help keep you safe and protected for years to come.

Their website even educates you on the danger of using alternate refrigerants for your air conditioner. Not only can it affect your a/c and how it performs, but it can also void the warranty. This is why it’s so important to let professionals handle any repairs or maintenance – which is something Lennox strongly supports as well.

In fact, Lennox takes the time to make sure all of their installers are licensed professionals and even ensure every supplier complies with applicable laws, including laws regarding slavery and human trafficking. Their dedication to being a quality company is rooted in making sure people are taken care of at every level.

Tankless Pro Has 35 Years Experience With Lennox

For all the reasons mentioned above, we are proud to associate ourselves with a brand like Lennox. They produce a quality product but also have a dedication to serving people – which is something we can relate to.

Our team of dedicated HVAC professionals has served Toronto and the GTA for more than 30 years. We’re confident we can help find a solution for any air conditioner or furnace problem you have. We’ll even work with you to determine which model works best in your home or office, so you save more on each monthly energy bill. Give us a call at 647-243-3571 to get started today. Rest assured when it comes to installing, maintaining or repairing a Lennox, we’re more than up to the task. Let us keep you warm in the winter and cool in the summer. Call today.

Unless you’re Scrooge McDuck, wasting money on a bad purchase for your home isn’t an option. When you’re face to face with deciding about the future of heating your home, make sure you have all the options in front of you. Take a look below to learn more about some furnace replacement options and how you can limit your costs.

Do Heat Pumps Make Sense For A Furnace Replacement?

The simple answer is yes – but it depends on your home. If you have an older 2-story brick house then installing a single heat pump may not be the best decision. If you’re living in a 2-story condo, then maybe it can be just right.

Heat pumps are designed to draw air in from outside, condense it, and distribute it to the surrounding area of where it is installed. Simply put, if it’s in your bedroom or living room, it’ll keep you toasty warm – but it’s not meant to heat an entire home.

Unlike a furnace, heat pumps don’t rely on ductwork. This makes them more efficient since they only heat a given area of your home. A furnace pumps warm air to every room in your home – whether you’re using it or not. This can lead to higher energy bills in the winter. Heat pumps are a great furnace replacement option if you’re looking to keep only key areas of your home warm in the winter.

Another furnace replacement option would be to obviously have a new furnace installed. If you’re living in a home with an older unit, replacing it with a newer energy efficient option could also save you more each month. Just make sure your home is properly insulated before booking any new installations – and make sure a professional does the work. It might be tempting to want to save a few bucks and do-it-yourself, but having a licensed HVAC technician perform the install means you’re not at risk to void your warranty, and that the job is done right the first time.

Tankless Pro Can Help With Your Furnace Replacement

We’ve spent more than 30 years helping homeowners and business owners alike in Toronto and the GTA. There’s nothing we haven’t seen, so give us a call at 647-243-3571 if you’re looking to learn more about your furnace replacement options. We’ll take the time to make sure you have the information you need to make the right decision for your needs this winter.