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How To Connect A Wood Furnace To Existing Ductwork

Wood-burning stoves are powerful heating devices; many appreciate their cost savings over gas and electricity. However, many homeowners ask how to tie a wood stove into ductwork to heat an entire home. Ducting heat from a wood stove is possible if you do it correctly.

You can connect a wood stove fan to a central heating duct, but joining a duct directly to a wood stove presents a fire hazard, not to mention smoke in your ductwork that is bad to breathe. Hooking a wood stove into ductwork works in reverse. It would be best to use a wood stove duct fan and possibly a damper to benefit from your stove’s warm air.

This approach will draw cold air from another room into your wood stove rather than forcing heated air into a far-off space. This will prevent too much hot air from the wood burner from heating the duct.

In our guide, you can learn more about heating your home from your wood stove and a furnace blower. By the end, you can set up an effective system that can deliver wood heat and warmed air through existing ductwork until the fire dies down and your regular old furnace takes over. (Learn How To Seal Door Threshold To Concrete)

Connect A Wood Furnace To Existing Ductwork

How Do Wood Stoves Work?

Wood stoves are manufactured from cast iron, steel, or stone and have a furnace, chimney, baffle, and damper. Once the wood is burned, the heat heats the stove and the room, and the smoke escapes through the chimney.

The wood stove’s baffle increases gas combustion, which is essential because partially combusted gases pollute the air. The damper controls airflow into the furnace, regulating fire size and heat output.

Basics of Warm Air and Wood Stove Ductwork

Directly connecting your wood stove fan to your central heating ducts is dangerous. Instead, you’ll need to construct a ceiling vent to use the duct fan technique in a distant room.

Run your duct through your ceiling and toward the stove after attaching it. Install a wood stove duct fan, ensuring it is pointed to draw air into the chimney.

Warm air will be released from your wood stove as cold air passes. This warm air may heat your house during the winter and be a significant heat source.

If the fan is freestanding and not in a fireplace, you can consider installing it atop the stove. A fan on top can circulate that heat upward and outside, keeping your house warm and comfortable. In addition, you might purchase a couple of oscillating fans to promote airflow. (Learn How To Clean Your Solo Stove)

Alternative Warm Air Circulation Options

Another option for circulation that functions similarly to a fan system is a plug-in blower. These plug-in blowers pull heat directly from the stove and direct it where you want it to go.

Such plug-in blowers for wood stoves do not lengthen burn periods, provide more heat, or boost efficiency. However, they circulate air around the stove, heat it, and then return it to the room. They do not force air into the fireboxes and are on the furnace’s exterior.

Installing a plug-in blower can aid in raising the temperature in the space. However, the engine that powers some of these blowers, like other types of fans, produces varying noise levels; therefore, some are loud. (Read Can A Window AC Unit Be Used Inside)

How to Use Wood Stove Damper

Since people first brought fire inside, wood stoves have been a common heating source. Over time, early attempts to manage and contain fire developed into installing wood stoves.

Using a damper is a part of controlling the heat and flames. After the doors are closed, this regulates airflow into the firebox.

Opening and closing the damper can influence how quickly and hotly a fire burns. Doing this may maintain your home’s ideal temperature using little or no wood.

  1. Align yourself by looking at the damper handle outside your stove or flue pipe. Some handles slide from side to side while others push in and pull out, turn clockwise or counterclockwise, or push in and draw out.
  2. If you are starting a fire, fully open the damper. By allowing the most airflow possible into the firebox, the flames from your newspaper or starter log will burn hot enough to ignite the wood.
  3. As soon as coals develop and the fire catches, close the damper about two-thirds of the way.
  4. More heat is drawn up and out of the chimney as it warms and the airflow picks up. The heat is increased by this flow, which warms the coals and forces air through the wood.
  5. To keep the heat in a larger home, open the damper halfway through one-fourth. Even though there will be too much airflow to generate heat if the damper is opened past halfway, the flame will continue to burn and consume wood.
  6. For nighttime or maintenance fires, such as when you go to the store, close the damper almost all the way.
  7. The little airflow allows smoldering coals and existing smoke to escape through the flue pipe but does not support flames and large-scale wood consumption.

House-specific temperatures vary, although a damper in “operational” mode is usually one-fourth open. This keeps smoke and air flowing out in the direction of the chimney.

A smaller opening would produce more smoldering and less fire, suited for an extended heating period. If you require more flames and heat, only keep the damper open more than a quarter of the way.

Installing ductwork to a wood stove

Wood Burning Stove Hot Air Ducting Advantages

With a wood stove, this system works excellently for heating many rooms.

The advantages of installing ductwork to a wood stove are:

  1. First, it helps in lowering the cost of heating.
  2. Increase the effectiveness of the fireplace’s operation.
  3. Reduce the temperature difference between the ceiling and the floor
  4. It helps to distribute the heat more evenly.
  5. The wood stove’s ducting heat helps distribute hot air to the desired rooms. The system may occasionally function throughout the house when working through insulated ducts.
  6. The fireplace is linked to the fan blowing on the wood stove. A bypass vent also balances the entire system. (Read Attic Door Won’t Close All The Way)

How To Distribute Heat From Wood Stove

Connect your wood stove fan to your fireplace or fire pit to ensure proper heat distribution through the central heating ducts. The plenum is the name for the heat distribution box.

Place it on the fireplace if you want it connected to the central heating system.

The woodstove should be close to the firepans as well. The fan will, therefore, be able to deliver hot air.

Here’s how to transfer heat from a wood stove in three stages:

  1. Instead of placing the collar at the top of the plenum, measure down approximately six inches from the plenum. Then, align the collar’s end with the plenum and use a marker on the sheet metal to mark the outside diameter.
  2. On the mark, you just drew, used a needle to make a hole in the plenum, and then put a scrap tin inside the hole. Cut the spot, and if there is a screw holding the top plenum in place, loosen it before pulling the top plenum.
  3. Integrate the initial collar into the opening. To keep the collar in place, bend the collar tabs. The inline stove fan and duck workup are now ready to be attached. Self-tapping metal sheet screws should fasten the duct to the stove.

You’re nearly finished. Now turn on the duct fan and the wood stove. Again, blowing the warm air across the entire plenum will be beneficial. Therefore, the central ducting system will be used to spread the heat.

If you’re wondering how to connect a wood furnace to existing ducting, adhere to the procedures above. (Learn How To Level A Ceiling With Furring Strips)

Alternative heat distribution methods

Here are alternatives to help with heat distribution.

  • Alter Stove Position: You can get better results if you install the stove in your basement. This is because the heat will warm the rooms above as it rises.
  • Use Ceiling Fans: A ceiling fan can help disperse heat. They will force warm air downward while pulling cold air upward to be warmed.
  • Maintain Suitable Insulation: If your home is adequately insulated, the heat you create won’t escape, and the cold air won’t enter. As a result, you can find a comfy location.

Pipe for wood stove


Which pipe should be used for the wood stove?

For a typical wood stove, you will need a single-walled stove pipe. The pipe must be thicker and constructed from sheet metal that is at least 24 gauges thick. The HVAC duct should not be used for wood stoves because of its triple-wall construction and unique design.

Can I vent a wood stove horizontally?

You can, indeed. Although all stoves require a venting system, the systems for gas, pellet, and wood stoves are distinct. The roof should always exhaust a ducted pellet stove. It can be vented vertically against the top or horizontally against a wall.

Do wood stoves heat the entire house?

The wood-burning stoves do more than only push air where you install them; they may heat the entire house, such as floors and walls, efficiently.

The stove generates more excellent heat while retaining the waste gases from the firebox for a long time. It can heat your entire house in this way. However, how the logs are stacked affects the stove’s effectiveness. (Learn How To Put Out Solo Stove)

Can I hook up flexible ductwork to the woodstove furnace and use a furnace fan?

Flex ductwork is not permitted unless it is solid metal. For duct work to be by code, there must be a 2″ clearance for the first 10 feet and a 1″ clearance after that.

Make a complete loop to ensure your wood furnace pushes air properly; connecting the cold air return is crucial. Note that modern conventional ductwork lacks the clearances required by code to run ductwork for solid fuel appliances.

Conventional furnaces cycle and won’t overheat ductwork or themselves since they have a high limit cutoff and a low limit.

Don’t run the furnace blower on your home furnace; doing so will conflict with any built-in blowers and cause the furnace to overheat.

You also don’t need to do anything with the return side of your ductwork because your stove will draw air from its installed room.

As your blower, furnace blower, and stove are in the basement, you may need to install a powered damper. Walking up and down to the basement whenever you wish to adjust the furnace or stove would be tiresome. Even adding control to a thermostat could save effort.

Can I connect a wood furnace to my duct work installation’s other end or supply side?

You may use a thermostat to shut off the supply side using a powered damper closest to where the heat pump duct enters the house in the winter months. This will stop the wood-fired heat from entering the heat pump when the heat isn’t running.

You might parallel-duct the supply duct and the wood furnace.

The installed basement wood furnace will only pull air from the supply and return heated air to the supply duct downstream, while the central house blower will manage the static pressure of the ducting. (Learn How To Cut Copper Pipe Close To Wall)

Keep the central fan turned on. Set the thermostat to a low but comfortable setting so that when the furnace runs out of wood, the hooked central heating system will kick on and keep the house warm.

How To Connect A Wood Furnace To Existing Ductwork