Wood Burning Fireplace Inserts

Why should you consider a wood-burning fireplace insert?

Simply put, it can improve your heating efficiency and reduce the cost of your electricity bill. The open look of traditional fireplaces is attractive, but comes at a high cost in heat loss. The wood-burning insert features a compact closed combustion chamber with a forced-air fan that produces more radiant, even-flowing heat while using less fuel and less room air.

An open wood burning fireplace draws air from the room into the firebox and pushes excess air up the chimney when in operation. This means that a significant portion of the heat generated by burning logs is dissipated before it heats the space. The

fireplace insert, on the other hand, typically uses only 5-15% of the fireplace's air volume. Some models also offer a combustion air kit that allows air to be drawn into the unit from the outside. So it's very efficient. A single load of firewood can run for hours. No more burning piles of firewood trying to heat your room.

Another feature that contributes to thermal efficiency is the small firebox. Fireplace inserts have a viewing window to see part of a cozy fire, but they require a compact firebox to maintain a hot, efficient fire. Some models can exceed 2,000 degrees Fahrenheit at the core of the fire. This will give you a hotter fixture that will devour wood and give off a lot of heat without wasting it in your chimney.

A blower or fan also contributes to the heat output of a wood-burning fireplace insert. These components come standard with fireplace inserts
Yes, the blower needs a little more foresight to power the device. However, the fan circulates heat from the fire around the room, maintaining a constant, even warmth.

How do fireplace inserts meet EPA standards? When it comes to inserts, more efficient heat means cleaner heat. Like wood stoves, wood stove inserts are subject to EPA efficiency standards. Current EPA regulations, Phase III, require all new stoves to emit less than 4.5 grams of smoke pollution per hour. A new regulation, Phase IV, due in May 2020, requires less than 2.5 grams per hour.

These criteria can be met with wood stove inserts through the use of several techniques. A carefully placed air hose soaks the fire in oxygen to create a hot, even flame. The firebox design also increases the residence time of hot gases before exhausting them into the chimney or chimney liner.

Older wood burning fireplaces emit 30-60 grams of smoke pollution per hour, depending on whether they are softwood or hardwood.

Types of firewood inserts
firewood inserts are mainly of his two types: catalytic and non-catalytic.

Uncatalyzed Wood Insert
This is the most common type of wood insert. These models have ceramic baffles, fireclay bricks, or sheets of vermiculite instead of catalytic converters.
These components seal off most of the upper part of the combustion chamber, leaving only a small space for smoke particles to escape into the ventilation system. A small air injection tube supplies oxygen to the fire. It also pushes smoke particles back into the fire to rekindle, minimizing smoke contamination.

Catalytic Woodburner
Although more commonly used in wood stoves, there are still some models of catalytic woodburners on the market. Instead of baffles, catalytic fireplace inserts use catalytic burners to reignite smoke particles. Catalytic converters are often honeycomb shaped and coated with metal. They react with smoke particles and reignite to produce water vapor and heat. Reigniting the smoke particles in this way produces less smoke overall. It also has a lower ignition temperature, so less heat is needed to start and maintain a fire.

Catalyst inserts often use a basic air recirculation system. This is similar to the non-catalytic model, but less complicated. A forced air system keeps the fire well ventilated and reduces soot and ash buildup.

For more information on catalytic and non-catalytic technology, see our article on wood stoves. With both catalytic and non-catalytic properties, wood-burning fireplace inserts work in the same way as wood-burning stoves.

How do I choose a fireplace insert?
Now that you know the basics of a wood-burning fireplace insert, how it works and how it is constructed, let's talk about how to choose the right fireplace.
Fireplace inserts are rated by BTU output and efficiency, with many manufacturers citing the optimal amount of space you can expect to heat.

Before deciding on a model it is important to measure the existing chimney in which the insert will be installed. Use a tape measure to record the front width and height of the chimney opening. Next, measure the depth of the opening and the width of the spine. Finally, check to see if the back of the chimney is leaning forward. In this case, observe the minimum depth of the top of the chimney.

These numbers will help you find the fireplace insert that fits your needs. Remember that bigger is not always better. Choose a wood stove insert designed to heat only where you need it. If you choose a bet that is too big or too small, you may not be happy with your purchase.

You will immediately notice that most fireplace openings are tapered, but not fireplace inserts. The width is usually the same or nearly the same from front to back. Most models of wood-burning fireplace inserts also offer at least two sizes of surrounds to cover the space between the edge of the fireplace insert and the hearth. In addition to choosing a wood insert that matches your opening, buy a surround that completely covers your fireplace opening.

Even when installing wood inserts in brick or prefabricated fireplaces, ventilation is also important to consider
Make sure there is enough clearance between the flue collar of the fireplace insert and the damper area of ​​the fireplace itself to install the liner. Some brick fireplaces have thicker lintels or narrower smokeboxes than others. In some cases, it may be necessary to structurally modify the chimney to make room for the vents. If any questions arise during the selection process, our friendly NFI Certified Technician will assist you in your selection.

How to Install the Wood Burning Insert

Once you have selected a Wood Burning Insert designed for use in your existing fireplace, you need to consider the installation process. Installing a fireplace insert has four stages: planning, preparation, installation and inspection. The process of installing fireplace inserts in masonry chimneys is a little different than industrially manufactured chimneys, but it is important to follow local codes and regulations.

Installing Wood Fireplace Inserts in Brick Fireplaces
Brick fireplaces are made on site and there is no specific agency that regulates them. This means that there are no specific rules governing the use of fireplace inserts in brick fireplaces.

Instead, check with your local government to see if restrictions apply. Then I would like to know what changes I need to make when installing the fireplace insert.You can get information from your city code office or county fire department. In some cases it may be necessary to use a special combustion air kit. Some require complete removal of the damper from the chimney.

Once you have verified that all local codes have been met, the fireplace is ready for use.
Space must be reserved for expansion. Therefore, identify a suitable power supply for your circulation fan and install a suitable liner for your ventilation system.

Installation
Site Preparation — If your fireplace has a gas lighter, you will need to remove it. Also, the gas supply should be capped and sealed with high temperature pipe thread sealant.

It may be necessary to sand down any rough stone or brick around the chimney opening. This gives the chimney a smooth surface that matches the surround flash.

Power Outlet – As mentioned above, these units come standard with a forced draft fan. Since most of the liner is contained in the firebox behind the metal surround, the fan prevents heat from being trapped in the firebox.

Fans require 120 volt power. Therefore, determine if it is possible to install sockets behind the fireplace. Are you satisfied with the power cord running next to your fireplace and leading to a nearby outlet?

Chimney Inserts — Installing the correct insert is critical to the safety and performance of your fireplace insert. Some gas fireplaces use aluminum liners, but wood-burning fireplace inserts require stainless steel liners. Typical grades offered are 304, 316 and 316Ti, each with higher heat resistance than the previous grade.

Most modern fireplace inserts use a 6 inch diameter chimney collar with a choice of flexible or rigid liner systems.
Fireplace inserts are always optimally stretched when fitted with a full lining. It continues from the insert chimney collar to the chimney top.

If the chimney is small or in the inner wall, a short liner will suffice. A short length is sufficient to fill the gap between the liner and the first clay tile of the chimney. As a rule of thumb, if your inner chimney is no more than 3 times the area of ​​your fireplace insert, or if your outer chimney is no more than 2 times your fireplace insert area, you can use a partial liner.

To install the liner, you will most likely need to remove the metal flap at the bottom of the chimney. Usually just lift the damper. However, if part of the liner is difficult to remove, there are also special adapters that allow you to thread part of the liner through the shock.

Mounting Wood Inserts Into Build-Up Fireplaces

Unfortunately, it is often very difficult to combine wood-burning fireplace inserts with a suitable build-up fireplace. There are several reasons for this:

The opening height of prefabricated fireplaces is usually lower than that of brick fireplaces. This limits the models of fireplace inserts that can be installed.
Many manufacturers explicitly prohibit the use of fireplace inserts. Alternatively, severely restrict use to a limited number of approved models. It can be difficult to find an insert with a flue collar that overlaps the
chimney flue itself. Two cuffs must be stacked to attach a flexible or rigid vent liner.

How To Clean Your Fireplace Insert
Want to keep your fireplace insert happy and healthy for years to come? Follow these tips and take the care you need to keep your device in top shape. Start by reading your owner's manual for specific cleaning instructions. Then use the right type and amount of fuel to prevent overignition. After all, chimneys are inspected annually.

Please read the instruction manual carefully. This goes without saying, but it's important to read the manual when it comes to fireplace insert safety and care - don't skip it! Minor troubleshooting issues related to the operation of your fireplace insert, or your specific model. You may find helpful advice on specific maintenance procedures.
Have your fireplace contents and chimney inspected by a professional once a year. Not only is this a safety precaution, it will also save you money by catching problems before they cause more damage.
Use correct fuel. Follow our recommendations for wood burning in your fireplace insert. Also remember that seasoned firewood burns more efficiently and produces less ash. (See here for more information on obtaining firewood.) Please do not burn garbage.
Don't let the fire get too hot. Fireplace inserts are designed to produce enough efficient heat, but misuse can cause the fire to get too hot and damage or ruin the insert.