How to Buy a Furnace

Having an efficient furnace is the key to keeping your house warm and cozy even in the harshest winter weather. But which furnace should you buy? If you plan on installing a new furnace or replacing the old one, you will have to make a number of considerations to find the best furnace. However, to make the most informed choice, it is good to understand how a furnace works.

What is a furnace?

A furnace is what heats up the air in your home. It works by blowing hot air through ducts in order to deliver warm air through air registers or grills. As a result, furnaces are also referred to as forced warm-air or ducted warm-air distribution systems. They use different types of fuel:

  • Fuel oil
  • Electricity
  • Natural gas

Prior to contacting an HVAC company, the first point you must remember is all fuel types have their pros and cons. Depending on how much space needs to be heated, one type of fuel may be cheaper than the other. In most cases, gas is considered to be the most inexpensive heating source. Now that you understand how a furnace works, here are the key considerations you have to make before buying one.


Some furnace types work better than others in various climates. You need to find a furnace with an Energy Star specific to the region you live in. Gas heaters with an annual fuel utilization efficiency (AFUE) of at least 80 are built for regions with mild climates. For regions with cold and freezing climates, you need a furnace with an Energy Star label for annual fuel utilization efficiency of 90 or more.

Furnace Type

Gas furnaces are undoubtedly the most popular type of furnaces because gas is readily available and less expensive. They come in three forms:

  • Single-stage gas furnaces: This features a gas valve that allows gas to flow at a single rate: high. These types of furnaces operate at about 80% AFUE. They are ideal for mild climates.
  • Two-stage gas furnaces: With this, the flow of gas can be adjusted between low and high. These furnaces can be controlled using a thermostat.
  • Modulating gas furnaces: This gas furnace can regulate heat precisely and is ideal for colder climates.

Other common types of furnaces are electric and oil furnaces. While not as economical as gas furnaces, electric furnaces are quite popular. They heat air using electric coils. On the other hand, oil furnaces are ideal for homeowners that don’t have access to other types of fuels.

Energy Efficiency

The higher the AFUE rating that a furnace has, the better. If the AFUE rating is 90%, that means 90% of the energy will heat the house while 10% will be lost. You, however, need to account for the cost of fuel. While electric furnaces are the most efficient, electric furnaces are the most expensive to operate. A furnace with an AFUE of more than 90% is ideal for very cold climates, whereas an AFUE of 80% will be perfect for milder areas.

Even with the above points in mind, you still need to install a furnace that is the right size for your home. Air Makers Inc. is happy to help you find the best furnace for your home.