are wood stove inserts worth it

Are wood stove inserts worth it? (When does it pay off?)

Wood stove inserts claim to increase the heating efficiency of your fireplace. But is it worth getting one? The initial cost of getting an insert confuses most people. Will the upfront costs ever be covered? In this article, we will look at the initial costs of a wood stove insert and the long-term savings. To do this, we will have to look at the efficiency of wood stove inserts. Also, we have to understand how much maintenance such an insert needs. I am going to do the research for you and let you know all my findings!

Quick answer: Yes, wood stove inserts are worth it. You can expect a $4,500 wood stove insert (including installation) to pay for itself within 3 years. After that, it will continue to save you money for a lifetime. Since wood stove inserts are made of durable steel, they will likely last for decades, if not forever.

What is the purpose of a wood stove insert?

A wood stove insert is a steel insert that will transform your existing fireplace into a stove.

It is commonly known that stoves are much more heating efficient than traditional fireplaces. This makes a wood stove insert a reasonable choice if your primary use of your fireplace is to heat your home. Traditional open fireplaces are highly inefficient in regards to heating because most of the hot air produced is rising up the chimney. This means you are effectively heating the air outside instead of your own home. The biggest advantage of a wood stove insert is that it employs the existing fireplace structure you have in your home. There is no need to remodel your home or remove your fireplace. The insert reuses your existing fireplace and the chimney.

Wood stove inserts transform existing fireplaces into stoves with minimal work needed.

If you decide to install a new stove instead, you have to deal with problems such as deciding if you should break down and remove the existing fireplace. And then you have to refurbish your living room.

Sounds like too much work? Get a wood stove insert.

Cost of wood stove inserts

Now that we know what a wood stove insert is and what it is used for, let’s have a look at how much it costs. I have found three different sources. As expected, all of them give different numbers.

According to homeguide.com, you can expect to pay $1,200 to $3,400. 

Another website presents the following numbers:

“Most fireplace inserts and a professional installation cost about $2,000 to $4,000, depending on the state of your existing chimney and the model you select. Some electric models cost significantly less, but they offer less heat output than wood and gas fireplace inserts.”

thisoldhouse.com

According to homeadvisor.com, the cost of a fireplace insert can be below $2,000. But installing new chimney liners adds to the cost. The average homeowner can expect an additional $2,500 of installation costs for a new chimney liner. However, this additional cost depends on the materials used and, of course, the quality of work. You can expect aluminum chimney liners to be significantly cheaper than cast-in-place chimney liners. Both solutions will get the job done. However, the cast-in-place chimney liner will likely last a lot longer.

When it comes to money calculations, I am more the kind of person that makes pessimistic assumptions. In the course of my life so far, this has proven a good decision. Let’s, therefore, assume the rather higher end of the price spectrum: Let’s assume $4,500 for a wood stove insert and chimney liner plus installation. For that price, you can expect to get a good fireplace insert, of course also with delivery, and everything is done for you from start to finish.

Why you need a chimney liner as well

Usually, with the decision to get a wood stove insert, you’ll also need to consider getting a new chimney liner. Both go hand in hand. Remember your main goal is to increase the efficiency of your heat source.

With a wood stove insert, you are effectively downsizing the burning volume of your fireplace. The space the wood has available reduces. Because of this reduced size, your chimney has to be adapted.

Aside from being responsible for exhausting toxic gases, your chimney has a second, less known job. Due to the chimney effect (or stack effect), taller and narrower chimneys “pull” more air than smaller and wider chimneys. It’s similar to the air pull you notice standing next to a nearly closed door. The reduced size of the wood stove insert, as compared to the former fireplace, causes less convection (less hot air rising). This in turn limits the ignitability of the fire. To produce lots of heat in a small stove chamber, you need a constant airflow. A chimney liner produces this airflow by making use of the chimney effect. It narrows the diameter of the chimney, causing the air to enter your stove with higher pressure.

As your chimney was likely designed with a big fireplace in mind, its wide diameter is not suitable for smaller inserts. The chimney liner ensures proper airflow and a balanced wood-burning rate. A certified chimney sweeper will know how to choose the proper dimensions for your chimney liner to ensure the highest heat efficiency.

How energy efficient are wood stove inserts?

According to studies, traditional fireplaces are only 5% efficient. This means that 95% of the potential heat energy goes straight out of the chimney. Your fireplace produces lots of smoke, which hints at the inefficient burning of wood particles. Only 5% of the heat produced, is actually used to heat your house.

After installing a wood stove insert, you can expect heating efficiencies up to 80%+. Only 20% of potential heat energy is wasted. By the way: 100% efficiencies are physically impossible. Anything above 80%+ is already really good. The reason is that perfect insulation does not exist and some heat will always be wasted by going straight into the ground or penetrating through the walls or somewhere else you don’t need it.

80% heating efficiency is a really nice result!

Why are wood stove inserts more efficient?

Oftentimes, the question arises as, why wood stove inserts are so efficient. Here’s the answer. The insert converts the convection heat (which is essentially hot air rising up the chimney) to radiant heat. Radiant heat doesn’t rise up such as hot air. Radiant heat spreads evenly in your home. It is the form of heat that you feel when you’re sitting in front of a fire and hold your hands against it. Or when you go outdoors in spring and the sun is shining on your face for the first time in the year even though the air is still cold. The fire inside the stove heats the steel stove container, which in turn radiates the heat everywhere making it cozy and warm.

The heat radiating from the wood stove insert will effectively heat all the objects in your room. The heated up room will then evenly heat the air everywhere and produce convection. See the difference?

In a chimney, the hot air leaves straight out of the chimney. An oven, instead, radiates and heats up the objects in your room, which then causes the air to heat up everywhere. Since the warm air is then trapped in your room, it can’t leave anywhere through convection.

Air is a heat insulator, which is why you feel warmer under thicker blankets as they contain more air pockets. When a traditional fireplace produces hot air, the heat contained does not radiate out as it is surrounded by more air acting as an insulator. Heat can only efficiently be transferred through the air by blowing the hot air into the room, or by radiating the heat waves.

Of course, fireplaces also produce radiant heat. And wood stove inserts also produce convection heat. The difference is just in the balance of heat forms.

wood stove insertfireplace
radiant heat80%20%
convection heat20%80%
Efficiencies of a wood stove insert as compared to a fireplace

How much money will it save me?

To find out how much money the installation of a new fireplace insert will save you, let’s first look at your current cost of heating. Since I don’t know the structure and building materials of your home, all of the following numbers will be estimations. But I’m giving my best at picking reasonable numbers. Let’s have a look.

I found across various forums that the average wood demand for stove users is 4 cords per year of heating. 1 cord is about 3.6 cubic meters (for our friends in Europe) of wood. There are also differences in how much wood you need depending on the wood you use for heating. Since various sorts of wood have different heating power 1 cord of beech wood will, for example, produce a different amount than 1 cord of spruce wood. But in general, you can assume 4 cords.

Also, take in mind that these numbers apply to stove heating only. They do not apply to fireplace heating because fireplaces usually need a lot more wood to burn than a stove. Since we have the efficiency ratings of a fireplace (which is 5% but let’s assume 10% for well-designed fireplaces) and wood stoves (80%), we can easily compare stoves and fireplaces with regards to their wood consumption.

The 80% efficiency of a stove is 8 times higher than the 10% efficiency of a fireplace. This means that to produce the same heat, a fireplace needs 8 times the amount of wood.

Let’s assume you heat only with wood. Therefore you need 4 cords of wood per year when you’re using a wood stove insert. A single cord of wood will cost you approximately $180 depending on your location. This means you’ll pay 4 times $180 equals $720 a year for heating with a wood stove insert.

To produce the same amount of heat with a fireplace (which rarely anyone is doing because of low efficiency), you need 8 times the amount of wood. This means you have to cover 8 times $720 equals $5,760 of heating costs.

This, in turn, means that you will save $5,760-$720 = $5,040 a year if you are purely heating with wood. Your wood stove insert with installation will pay for itself within just one year, since we estimated $4,500 for that.

Obviously, this calculation is rigged. I assume that you use a traditional fireplace to heat your whole house. Also, I assume your fireplace heating wood usage increases to make up for the reduced efficiency of the fireplace. This is rarely the case. Therefore let’s be a little more pessimistic. Let’s assume you’ll save a third of the calculated sum: $5,040 divided by 3 is $1,680. The investment will still pay for itself within 3 years. As long as you are regularly heating with wood, a wood stove insert is always worth it and will pay for itself. A wood stove insert is not worth it if you plan to use it only sporadically, eg. when guests are around or only on weekends.

Does a wood stove insert need maintenance?

Yes, a wood stove insert needs maintenance. However, the maintenance involved is not much more than for maintaining a traditional fireplace. If you don’t currently heat with wood, here’s the maintenance tasks you will have to face:

First, the wood itself needs work. You need to cut up wood, split it and organize it into cords. You’ll need some gear to do that, such as a splitting maul to split the wood. And you’ll need one or more wood racks to store and dry the wood. Also, you need space to store the wood chopping gear and the wood itself. Additionally, you’ll need fireplace tools and a woodstove glass cleaner. Don’t forget the lighter!

Conclusion

If you like to heat with wood, a wood stove insert is always worth it. If you are a “show off heater” who uses the fireplace only occasionally, stick to your fireplace. A wood stove insert is a reliable source of efficient heat. Your fireplace is enough if all you want to achieve is some supply of heat to comfort some guests.

Additional credits: shawnredsox808 (title image)

About the Author

Daniel Hirsch

Daniel is an electrical engineer, blogger, and author. He studied electrical engineering and information technology and decided to blog about heaters after working in the temperature sensing industry.