Buying a High-efficiency Furnace


Many home homeowners have resorted to buying high-efficiency furnaces owing to their cost-effective nature. Buying a high-efficiency furnace not only saves you money on bills but also provides more comfort.

Although it can be quite expensive to install, a high-efficiency furnace can last a minimum of 10 years. With proper maintenance, a high-efficiency furnace can last as long as 20 years.

Rather than go for mid-efficiency furnaces that don’t guarantee the desired results, invest in a high-efficiency furnace. High-efficiency furnaces are a more convenient way to keep warm during cold months with a variable-speed blower. In addition, a high-efficiency furnace ensures there are no hot and cold pockets in your home.

This buying guide will help you enjoy all the benefits of owning a high-efficiency furnace. Here, we’ll discuss how to pick the right size for your home, installation recommendations and pricing options.

What is the Cost of a High-efficiency Furnace?

There are different types of furnaces in the market today. Depending on the furnace model you choose, you can spend around $1500 and $6500 for a new furnace.

Typically, mid-efficiency furnaces cost around $1500 to $2500. However, compared to High-efficiency furnaces, mid-efficiency furnaces have an AFUE (Annual Fuel Utilization Efficiency) rating of 80% to 89%.

Furthermore, a mid-efficiency furnace may require you to create a new chimney. Typically, mid-efficiency furnaces vent through a metal or masonry chimney. If your chimney isn’t either, you may have to upgrade your chimney.

On the other hand, buying a high-efficiency furnace can cost about $3000 to $5000. High-efficiency furnaces AFUE rating is 90% to 97%. The difference in mid-efficiency furnaces and High-efficiency furnaces AFUE rating shows high-efficiency furnaces are more energy-saving.

Unlike mid-efficiency furnaces, High-efficiency furnace vents through your wall via PVC pipe. To install a new high-efficiency furnace, you won’t need to upgrade your chimney.

Additionally, high-efficiency furnaces are built to retain more energy by using less gas to heat your home. They evenly distribute heat around your home, providing you with more comfort during the colder months. 

Key Features of a High efficiency furnace

A high-efficiency furnace with a 90% AFUE rating or higher uses a second heat exchanger. The second heat exchanger heats air from the condensed exhaust gases, thereby causing it to reach higher efficiency.

Furthermore, a High-efficiency furnace efficiently burns fuel to run the blowers responsible for heat circulation in the home. Likewise, if it’s an electric furnace, it requires minimal energy to circulate heat. Therefore, furnaces capable of using less energy while doing more are classified as high-efficiency furnaces.

Prior to buying a high-efficiency furnace, it’s important to be aware of its features. Often, homeowners are only on the lookout for their AFUE rating. Although AFUE rating can distinguish a High-efficiency furnace from a mid-efficiency furnace, there are other features. Here are some features to help you choose the right high-efficiency furnace.

Two-stage heating (gas valves and motors)

A high-efficiency furnace features a two-stage gas valve. The two-stage gas valve quickly heats the furnace before dropping the temperature. By dropping the temperature, the gas valves allow the furnace to save fuel.

Furthermore, High-efficiency furnaces that run on gas saves on electricity used in powering the blower motor. The furnace couples a motor with variable speed and a programmable thermostat. However, its electricity-saving feature isn’t usually considered when calculating the furnace’s AFUE rating.

Usually, traditional gas furnaces are either on or off. This is because they don’t have the capacity to move between both states automatically. When a gas furnace is running, it quickly heats up. Therefore, supplying a large amount of heat in a short time.

Because of the sudden heating, there may be temperature fluctuations when the furnace is on. The temperature fluctuations can be uncomfortable, especially during mildly cold weather.

Additionally, during moderate weather, most traditional gas furnaces develop a fault called short cycling. Short-cycling increases the rate at which the furnace wears out.

Also, traditional gas furnaces don’t allow the air in your home to circulate properly. The reason is due to the fact they shut down shortly after heating up.

However, unlike traditional gas furnaces, a variable-speed system causes the blower to run for a longer time. Also, it allows the blower to run at a slower speed. Additionally, a High-efficiency furnace is quieter and more comfortable than a traditional gas furnace. 

Electronic ignition

Electronic Ignition

When you turn on your gas furnace, natural gas and air combination enter the combustion chamber. For traditional gas furnaces, you’ll have to ignite the pilot light for the furnace to function. Also, the pilot light has to be constantly burning, although it has a tendency to go off.

High-efficiency furnaces are not like traditional furnaces with a  pilot light. A pilot light increases the inefficiency of a furnace as your furnace won’t work if your pilot light goes bad. 

A High-efficiency furnace comes with electric ignition. The ignition changes electric energy to heat which when hot ignites the burner. Also, the electronic ignition heats up quickly to ignite the burner, saving you fuel. The advantage of electronic ignitions is they make your furnace more reliable. 

Furthermore, the best high-efficiency furnace models are referred to as condenser furnaces. In a condenser gas furnace, the exhaust gases pass through a secondary heat exchanger. The heat exchanger extracts what’s left of the heat from the gases. 

When the extracted gases are no longer hot, they condense. After they condense, they form a carbonic acid which is a combination of carbon dioxide and water. Also, the water is referred to as condensate. 

The condensate goes out through a good drainage system, venting out the flue gases that remain. The flue gases are vented out of the house through a PVC pipe. When the pipe is venting out the flue gases, they are cool, showing how safe condenser gas furnaces are. 

A High-efficiency furnace is capable of producing condensate of up to 6 gallons daily. You can drain the condensed water by connecting a condensate pump to your furnace.

Additionally, when buying a high-efficiency furnace, one thing to look out for is its heat exchanger’s warranty. The best heat exchangers can resist chemical and moisture build-up capable of causing corrosion. 

Variable speed

One advantage of buying a high-efficiency furnace is the optimal comfort you get. With its variable-speed blower, you can regulate how much heated air your furnace produces. Contrastingly, traditional gas furnaces don’t have this option. As a result, they produce too much heat when your heating demands are low. 

What variable-speed fans do is circulate heated air into your home at a low rate. Typically, it pushes the heated air slowly into your home when the demand for heat is low. The regulated speed allows the furnace time to distribute heat evenly to every room in your home.

Likewise, the blower keeps pushing heated air to every room even after shutting down the furnace. Because of this, you’re less likely to have temperature fluctuations in your home. 

Sealed combustion chamber

The combustion air intake of your gas furnace is connected from outdoors to the furnace. By this, we mean your furnace doesn’t use the heated air it produces for combustion. 

Additionally, you can install your gas furnace in a way that it takes combustion air from indoors. This installation method is known as single-pipe non-direct vent configuration. You can use this installation method if the furnace location is in a cold place like the basement or utility room.  

High-efficiency air filters

Buying a high-efficiency furnace assures you of improved air quality in your home. Usually, many high-efficiency furnaces come with quality air filtration. However, it would help to change your air filters regularly to get the best out of them. 

Also, there are various air filters you can use in your home, depending on your preference. For instance, using air filters that capture allergies is ideal if you have allergies. 

Related Article: Furnace Repair Guide

How to Determine a High-efficiency Furnace’s Power

When buying a high-efficiency furnace, you should note its AFUE rating. Most manufacturers refer to their furnaces as highly efficient, but they aren’t. A furnace with an AFUE rating between 80 and 83 percent is mid-efficiency.

Furthermore, all new models of furnaces come with an AFUE rating in a yellow Energy Guide label. The label is a requirement of the Federal Trade Commission, otherwise known as FTC. Also, the guide lists the expected cost of operating a furnace annually. However, the list is solely used for comparison while shopping for buying a High-efficiency furnace. 

The minimum AFUE rating is 80%, while the highest is 98.5%. The percentage represents the annual fossil fuel of the furnace that’s converted to heat. By this, we mean a high-efficiency furnace with a 98% AFUE rating converts 98% of its fuel to heat. 

However, it suffices to know that the above rating is solely for gas furnaces. The AFUE rating of electric furnaces is always 100%, and the reason isn’t farfetched. Electric furnaces don’t have exhaust pipes, making them retain all their energy. Also, the electric power of an electric furnace is completely converted into heat. 

Because electric furnaces don’t lose any heat doesn’t mean it’s a more cost-effective option than gas furnaces. On the contrary, gas furnaces aren’t just cheaper to install but also cheaper to run. The reason is that electricity is more expensive than gas. 

Eventually, you end up spending more on electricity bills, making the purchase not worth it. However, you can install a new high-efficiency gas furnace if you’re concerned about high electricity bills. 

Factors to Consider Before Buying a High-efficiency Furnace

High-efficiency furnace installation can cost a lot initially but is worth it in the long run. Aside from the installation cost, another thing to consider before buying a high-efficiency furnace is the size. 

Additionally, you should consider the energy source of your furnace. Here are some factors to consider before buying a high-efficiency furnace.

Energy source

Furnaces have three main sources of fuel which are electricity, oil, and natural gas. Before buying a high-efficiency furnace, research how much the three energy sources cost around you. Also, calculate how much it would cost you to run a furnace on any of the three energy sources.

Switching to a different energy source for your new high-efficiency furnace is a good idea. However, you should factor in how much it’d cost to install a new furnace.

Furthermore, oil and gas furnaces are ideal for colder places as they produce more heat than electric furnaces.  However, the cost of maintaining a gas furnace is higher than other types of furnaces.

If you’d be buying a high-efficiency gas furnace, bear in mind the maintenance costs. Inadequate maintenance of your gas furnace can lead to gas leaks or fire.


It’s common to find furnaces that come with a warranty from their manufacturer. Likewise, furnace installation companies offer a labor warranty when installing a new furnace. Typically, the manufacturer warranty lasts for about ten years. However, you will be required to follow strict maintenance guidelines to validate your warranty.

Furthermore, some furnace manufacturing companies require that homeowners register their furnaces to claim their warranty. Additionally, it would be best if you got a written warranty from the installers. Installation warranty is often valid for nothing less than a year.

Maintenance cost

Buying a high-efficiency furnace comes with costs asides from purchase and installation costs. One of such costs is changing your furnace’s air filter every three months. Also, for furnaces that come with filters, you’ll be required to clean them monthly.

Proper maintenance of your air filter can save you money on having to do a major repair. To maintain your furnace’s efficiency, you have to call a technician to do a routine checkup. Averagely, it costs between $100 and $125 to tune up your furnace. Also, you can get a new air filter for about $30.

Furnace brand

Furnace Brand

The market is replete with various brands of furnaces, and choosing the best can be difficult. Some leading furnace brands are

  • Carrier
  • American standard
  • Trane
  • Lennox
  • Bryant
  • Rheem
  • Ruud

It’s important you go for reliable brands which are less prone to breakdown, unlike some furnace brands. Also, in some Canadian states, some heating companies qualify for full government rebate programs.

For example, replacing your old furnace with a new high-efficiency furnace in Ontario gets you about 650 from the Ontario Power Authority. You must check to see if the furnace brand qualifies for the rebate before making a purchase. Here is the guide to government rebates.

Importance of Furnace Size when Buying a High-efficiency Furnace

Determining the size of a high-efficiency furnace to buy for your home can be tricky. Usually, you’re to consider the landscaping of your home and its square footage.

Buying the right high-efficiency furnace for your home can’t be overemphasized. A furnace too big for your home is likely to short-cycle. Also, irregular cycling of your furnace can cause cold and hot spots in your home. 

In addition, a furnace too big for your home can impact the furnace’s efficiency and reduce its lifespan. You also get to spend more maintaining such a furnace.

On the other hand, an extremely small furnace won’t give you the desired warmth. The furnace will keep running, increasing the energy bills and reducing its lifespan. Also, the increased workload can cause you to spend more on maintaining the furnace. 

Measure the size of your furnace

Measuring the size of your furnace isn’t only about its physical dimensions. Furnace size measurement is according to how much heat it can produce and the heating output. 

Typically, you measure furnaces in BTUs per hour. It refers to British Thermal Units, which are a way of measuring energy. Also, it measures the amount of energy needed to increase a pound of water by 1F. Buying a high-efficiency furnace according to the square foot is as follows,

  • 1200sq.Ft house: 36000-72000 BTU(s)
  • 1500sq. Ft house: 45000-90000 BTU(s)
  • 1800sq. Ft house: 54000-108000 BTU(s)
  • 2100 sq. Ft: 63000-126000 BTU(s)
  • 2,400sq. Ft house: 72,000-144,000 BTU(s)

Furthermore, you’re to consider some other factors when sizing the right high-efficiency furnace for your home. These factors are:

  • Exterior walls
  • Doors and windows
  • Insulation
  • Ductwork
  • Added sources of heat
  • Home orientation, style and layout
  • Climate

Conclusively, depending on where in Canada you live, the climate varies drastically. Check the North American Insulation Manufacturers Association guide for your insulation requirements and climate zone.

Related Article: How Do I Keep My Furnace in Good Condition?

To Wrap It Up

Knowing how to choose a high-efficiency furnace can be easy with the right information. Having a buying guide makes things easier and allows you to make the best decision. A high-efficiency furnace, unlike traditional furnaces, is cost-effective and requires minimal maintenance.

Because buying a high-efficiency furnace is quite expensive, you must install it properly. Only experienced installers should handle a complex installation like a high-efficiency furnace. With ALP Heating, you’re at peace knowing your furnace is in safe hands. Check out our furnace installation services in Vaughan today!

ALP Heating is committed to providing the finest service possible to important areas. We are delighted to be your go-to cooling and heating business for all of your requirements. Because of our commitment to perfection.