Few could have predicted a day when there are so many types of furnace to choose from for your home. Unsurprisingly, homeowners are often left baffled when shopping for a new furnace. This is because there are so many to choose from.
To make your life easier, we’ve made a condensed list. We’ll walk you through only the best types of furnaces that are worth taking into consideration.
What are the types of furnaces?
For those in a rush, you can refer to this segment that gives a quick rundown of the main types of furnaces. These will be explained in more detail further down the article.
Essentially, the main types of furnaces are the natural gas furnace, the electric furnace, the oil furnace, the propane furnace, the wood furnace, and the dual fuel furnace. Generally, electrical furnaces are more affordable in their upfront costs, while gas furnaces have lower operational costs.
What is a furnace?
Before moving forward, let’s better understand what “furnace” means in this context, as its definition has evolved over the years. In ancient times, the term was used primarily to refer to large oven-like objects. These are made of iron or an equivalent metal with an intense fire inside.
In fact, the word “furnace” was derived from the Latin word “fornax” which literally means oven.
Nowadays, a furnace is not necessarily a large boiling pot of fire but can take on many forms, such as gas, electric, or oil furnaces. A standard HVAC system often has a furnace built inside or as part of the air ducts. This is responsible for heating air and regulating high temperatures in the home.
Depending on the type of furnace, the method by which the HVAC system generates heat will differ. However, it typically involves a heating element that raises the surrounding air and a fan that transfers the hot air across the room.
Types of furnaces
While many types of furnaces go beyond this list, you will find that they all fall under one of these categories in one way or another. The following five types of furnaces are the most popular and best-selling options currently on the market today. Each offers unique benefits and minor drawbacks that will be discussed below.
Natural gas furnaces
Arguably the most popular of all furnaces is the natural gas furnace. And rightfully so, due to some of its unmatched benefits and homeowner advantages.
First and foremost, natural gas furnaces are the most budget-friendly type available. They offer incredible energy efficiency even when using the heating system all day. Nearly half of all Americans heat their homes using natural gas furnaces. They experience little to no issues with them thanks to their long lifespans of performance.
Natural gas is also among the cleanest fuel varieties as it is a naturally occurring mixture of carbon and hydrogen. In addition, it is one of the cheapest fossil fuels available to us.
Furthermore, this type of furnace is highly eco-friendly. Its natural toxic-free composition means that pollution is minimized when in use. Truthfully, natural gas furnaces can have a relatively high upfront cost compared with other furnaces. However, the long-term savings on energy bills is worth the investment.
Besides its high initial cost, one of the additional downsides of natural gas furnaces is that you will need a municipal gas line. This means those living in remote areas may have difficulty installing them.
Furthermore, in the unlikely event that the heater malfunctions, harmful carbon dioxide emissions may be released into the air. This puts you at risk of airborne poisoning.
Overall, natural gas furnaces are incredibly economical despite some drawbacks. Homeowners across America have reported 98% efficiency results with newer furnace models.
If you’re looking for a lower-priced unit with an affordable upfront cost, nothing is quite as appealing as electric furnaces. Perhaps the cheapest furnace type currently on the market, the electric furnace offers a long lifespan.
It is also considered one of the safest options for homes. This is because electric furnaces don’t run the risk of gas leaks, which pose the threat of releasing toxic chemicals. In addition, other types have more potential for fires if an unlikely malfunction occurs.
Electric furnaces typically require a blower motor and heating coils. This allows electric currents to pass through once the thermostat has been triggered, causing them to heat up to extremely high temperatures.
Unfortunately, the running costs of electric furnaces are significantly higher than that of natural gas. This is the factor that diminishes the appeal of its low upfront cost. Nevertheless, there are ways to minimize your electric bills. For example, you can connect your electric furnace to solar panels to reap the benefits of renewable energy absorption.
Oil or oil-fired or waste oil furnaces refer to those that convert oil into heat. The heating method with this type of furnace typically involves burning oils that are no longer usable for their intended purpose. These include old vegetable or motor vehicle oil, and using the heat produced to create warm air in a house room.
As you would expect, this heat production method is quite environmentally friendly as it encourages reusing old oils. These would have likely been disposed of in a way that harms the environment otherwise.
In terms of energy efficiency, oil furnaces can reach 80% efficiency with a maximum of about 90% efficiency. This makes it comparable to natural gas furnaces in terms of energy savings.
One of the most significant benefits of oil furnaces is that they do not require specific gas lines to operate like natural gas. This makes it one of the popular choices for homeowners in rural and remote areas. As such, it is not uncommon to see oil furnaces in a typical household in the northeastern part of the USA, where municipal gas lines are rarer (1).
While these furnaces have a long lifespan and can be cost-effective and eco-friendly, they have some downsides. For example, oil furnaces usually require more maintenance than gas furnaces, ultimately contributing to the overall operational costs.
Also, there may be costs related to maintaining a sufficient waste oil stock. For example, not all homes have oil supplies ready to be burned and converted into heat.
As its name suggests, these furnaces require liquid propane to operate. They need the leftover by-products produced by oil and gas production. Fortunately, propane is relatively easy to find and affordable as an upfront purchase.
This type of furnace is popular among those without the required gas line connection, much like its electric furnace and oil furnace counterparts.
To put things into perspective, propane furnaces are used by about 10% of the American population. They are most commonly found in households that do not have access to a natural gas line or oil reserves.
While propane is reasonably priced as a one-off purchase, it is inefficient compared to natural gas. This means you must regularly purchase new propane stocks, especially if you live in colder climates requiring constant temperature regulation.
Propane is one of the more eco-friendly furnace types alongside natural gas and oil. As a result, you won’t have to deal with an increased monthly energy bill like that of electric furnaces.
Wood burning furnaces
A blast from the past, the wood-burning furnaces feature a solid metal enclosed heating chamber that contains burning flames fueled by natural wood blocks. These are typically seen among older gas furnaces, but even today can deliver optimally heated air for your household that can even reach as high as the ceiling height.
In areas of abundant access to wood, these wood furnaces can prove to be an extremely cost-efficient option. It allows you to save energy while enjoying access to an almost unlimited fuel source.
Much like a pizza oven, these box furnaces or “open hearth furnaces” are independent from your home’s air conditioning unit (2). Therefore, they must be managed as a separate entity. Unfortunately, this can cause inconvenience in modern-day households as wood must constantly be fed into the furnace to sustain the heat source.
Perhaps for this reason, wood furnaces have decreased in popularity over the years due to their inability to keep the house warm when nobody is around to keep the heated elements running.
Dual fuel furnaces
Last but not least is a unique concept called dual fuel furnaces, which, as you might’ve assumed, uses two fuel sources for its operation, an electric heat pump, and a gas furnace. One of the core components of dual fuel furnaces is an air handler built into the heat pump, which essentially works by removing the heat from the outdoors and blowing it into your home.
This heating process is used primarily during cool (but not freezing) weather, as it shines brightest when used in moderation due to its higher cost of operation.
When the weather worsens, the dual-fuel furnace will switch to gas operation, which will work much like a standard gas furnace. However, alternating these two heating elements promotes substantial savings in energy, making this modulating furnace one of the most cost-efficient ways of keeping the home’s temperature regulated.
The only real downside of dual fuel furnaces is their initial installation cost, as it requires a rather complex design structure to get the best of both electric and gas fuel sources.
Final thoughts on types of furnaces
As discussed, a few different types of furnaces are rather popular today, with natural gas furnaces leading the competition by a landslide. Depending on your geographical location, access to resources, and personal preferences, any of these furnaces could be considered a viable option.
Be sure to check the annual fuel utilization efficiency for each furnace, as this will indicate what to expect in running your new furnace.
Types of furnace FAQ
What type of furnace is most efficient?
Natural gas furnaces are the most efficient types of furnace as they can reach up to 98% efficiency ratings for newer models. In addition, they begin heating air fast and can be used in conjunction with a variable-speed blower to spread the heated air across your desired vicinity efficiently.
What is the most common type of furnace?
The most common type of furnace is the natural gas furnace, comprising nearly 50% of all American households. They provide amazing heat treatment and enable homeowners to save on energy bills. This is due to natural gas’s long lifespan and wide availability, making it the cheapest of all fossil fuel sources.
What are the different style furnaces?
There are many different styles of furnaces. These include bell furnaces, modulating furnaces, single-stage furnace, quenching furnaces, two-stage furnaces, forging furnaces, box furnaces, and tempering furnaces. These furnaces are typically compatible with all fuel sources, including natural gas, oil, electric, propane, and wood. But, of course, it depends on the type of model in question.
What are the 3 types of furnaces?
The three main types of furnaces are natural gas, oil, and electric, comprising most American households. In remote areas, it is common to find propane furnaces due to their convenience in accessibility in areas of no gas line connections.