Can A Wood Stove Be Too Big? (Or Even Too Small?)

In Indoor Fireplaces, Multi Fuel Stoves, Wood Burning Stoves by James O'KellyLeave a Comment

Wood burning stoves help to increase the heat output from burning wood in your home, and in general the larger the stove the more heat can be generated.

But can a wood stove be too big?

A wood stove can be too big for the amount of space that it’s heating. Wood burning stoves should be sized accordingly with the area that’s intended to be heated. A wood stove that’s too big and causing the area to become too hot can lead to it being underutilized and underperforming.

I’ve explained in more detail below using our own wood burning stove as an example why a stove should be sized accurately for a room or home, and what can happen if it’s not.

Can A Wood Stove Be Too Big?

A wood burning stove can be installed within your existing fireplace to help improve the efficiency and amount of heat generated when burning wood. To help increase the amount of heat produced from every piece of wood consumed, wood stoves allow you to be able to control both the amount of fuel on the fire and the amount of air being supplied.

A fire needs both oxygen and fuel to survive. Increasing either the amount of wood on the fire or the amount of oxygen getting the fire, or both, can help to increase the amount of heat that is being radiated by a wood stove into your home.

Every model of wood burning stove is sized differently, and the heat output of a stove can correlate with the size of it and how much wood can be placed inside the firebox at any one time.

Different sized stoves can hold different amounts of wood, and be able to generate higher or lower amounts of heat as a result

A larger sized wood stove will be able to hold more wood, and so more heat will typically be able to be produced as a result. The actual heat output of a stove can also depend on it’s efficiency rating (how well it converts the energy stored in the wood into heat), as well as how well it radiates out heat into your home and how much air is being supplied to the fire through the vents at any one time.

When choosing a wood stove you’ll be able to see the amount of area it can typically heat (usually measured in square feet), as well it’s optimum heat output (usually shown in BTUs or kW).

Our wood burning stove (a Parkray Aspect 5 Slimline) is a 4.9kW model (about 16,000 BTUs per hour) that was chosen because it’s sized correctly for heating our living room. It’s not too big and it’s not too small.

Our wood burning stove is sized correctly for the area it needs to heat, which in our case is our living room

If a wood stove is sized too big for the area that it’s heating then there can be a tendency to run the stove at sub-optimal performance, having fires that are too small for the size of the stove or the air vents being closed down in order to reduce the heat output.

It’s not recommended to have fires that are too small for the size of the stove or to close down the vents by too much. A small fire in a larger sized wood stove can lead to a stove that’s not reaching operating temperatures, and closing down the air vents too much can lead to a smoldering fire that’s not burning efficiently.

If you need to build small fires because your wood stove is too big, you can use firebricks to line the sides of sides of your stove inside the firebox to help reduce the internal size of your stove.

A wood stove helps to improve the efficiency of burning wood by increasing the amount of heat being produced through processes such as secondary combustion, which helps to burn off waste gases produced by the fire to produce even more heat.

Secondary burn requires higher temperatures within the stove to initiate.  Building fires too small in a stove because it’s too big can lead to wood that is burning inefficiently where the most amount of heat isn’t being produced.

An inefficiently burning fire can also lead to more smoke being produced.

As shown by our stove thermometer below, there is an increased chance for creosote (tar) to be produced by a stove if the stove is operating at too low of a temperature.

Stove Thermometer
Building a fire too small to compensate for an oversized wood stove can lead to poorly burning fire

Increased creosote production can line the inside of your flue or chimney more quickly, leading to you needing to have it swept more regularly, as well as seeing the glass on the door of your stove stain at a quicker rate.

A poorly burning fire can lead to the glass on the stove door staining more quickly

If a stove is too big for the space it’s heating, the user may not want to run a wood stove at operating temperature because it can cause the room or home to be too hot.

Wood stoves can put out a lot of heat compared to open fireplace fires. We have to take off any extra layers we’re wearing when our wood burning stove has reached its optimum operation temperature. If our stove was sized too big for our room then it would make us want to leave the room, required us to open a window or lead us to building small and inefficient fires inside the stove.

It’s therefore important to choose the right sized wood stove for the area you want it to heat so that’s it’s not too big, which can to fires being had that are too small for the size of the stove.

Can A Wood Stove Be Too Small?

A wood burning stove can also be sized too small for the area it’s heating, leading to the stove being over used to bring temperatures up.

While having a wood stove that’s too big can lead to having fires that are too small to help bring temperatures down, a stove that is too small in size can lead to having fires that are too large for the stove as you try and bring temperatures up within the room.

Each wood stove is sized to take a certain amount of wood to operate the most efficiently. If the size of the stove is too small and isn’t heating the room effectively as a result, then more wood can be added to the stove over what’s recommended to help increase the heat output.

Although more heat is being produced, hotter fires are less efficient than lower temperature fires because the fire is burning through the wood at a greatly increased rate.

Our stove thermometer also shows that a stove can be operating too hot.

Multi Fuel Stove Too Hot
Building a fire too big in your wood stove because it’s sized too small can lead to a stove that’s burning too hot

Furthermore, continuously burning fires that are too hot for your stove can result in over firing, which in turn can cause the main components of the stove to become permanently damaged over time (most commonly the baffle plate).

It’s therefore also important to ensure that a wood stove isn’t sized too small for a room or home so that it doesn’t get operated at too high of a temperature too often.

In some cases it may be better to have a stove that is too big rather than being too small, as you can leave a door or window open to help reduce the temperature in the room rather than over firing a small wood stove to bring up temperatures.

Whatever the type of stove you’re looking to buy, be sure to have a professional size up the right wood burning stove for your particular situation to ensure that you’re buying the right sized wood stove.

Further Reading

Parts Of A Wood Stove Explained

How To Use A Wood Burning Stove

How A Wood Stove Works

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