April 16, 2022

Updated August 28, 2026

Double Barrel Wood Stoves: Everything You Need To Know

A double barrel wood stove uses two stacked 55-gallon steel drums as a simple heat exchanger: the lower barrel holds the fire, and the upper barrel — connected by a short length of stovepipe — captures heat from the rising smoke before it exits the flue, radiating that extra heat into the room instead of losing it up the chimney.

How It Works

The two barrels are stacked vertically, one on top of the other, and connected by a short section of stovepipe. The lower barrel is where the wood actually burns. The upper barrel doesn’t hold fire at all — it sits in the path of the hot flue gases on their way out, absorbing heat from them and re-radiating it into the room. Some designs add horizontal tubes running through the upper barrel to increase the surface area exposed to the rising heat, sometimes paired with a fan to push room air across them faster.

Advantages

Fuel efficiency. Because the upper barrel recovers heat that would otherwise go straight up the chimney, a double barrel setup can produce more usable heat per log than a single barrel or basic firebox stove of similar size.
Low cost. A double barrel stove is commonly built from a single 55-gallon drum plus an add-on kit (sold by retailers like Tractor Supply), making it one of the cheaper ways to add wood heat to a garage, workshop, or outbuilding.
Long, steady burns. A well-packed load of wood in the lower barrel can burn for several hours without reloading, though how long depends heavily on wood type, how tightly it’s packed, and how the airflow is set.

Limitations and Real Drawbacks

Burn control is limited. Barrel stoves typically rely on a simple air-inlet damper rather than the more refined combustion-air controls found on manufactured stoves, so precisely dialing in heat output and burn rate is harder than with a modern stove.
Most are homemade, not certified. A barrel stove built from a drum and an add-on kit is generally not tested or certified the way manufactured wood stoves sold new must be under EPA emissions standards. That doesn’t automatically make a barrel stove unsafe, but it does mean there’s no independent emissions or safety testing behind it the way there is for an EPA-certified stove — installation, clearances, and combustion-air setup are entirely on the builder to get right.
Not designed for coal. A barrel stove lacks the grate and underfire air supply coal combustion requires, so it’s built specifically for wood.
Design has stayed static. Because these are largely a DIY/kit product rather than a manufactured appliance line, there isn’t the same ongoing engineering investment you’d see from a commercial stove manufacturer.

Making a Double Barrel Stove More Efficient

A few things genuinely help heat output and burn quality:

Raising the lower barrel off the floor (on legs or fireproof blocks) improves airflow underneath and reduces heat loss into the floor.
A damper installed in the connecting stovepipe between the two barrels gives you real control over burn rate and heat output — without one, you’re largely at the mercy of however much air the design lets in.
Well-seasoned, dry hardwood burns more completely and produces less smoke and creosote than green or wet wood, which matters more on a barrel stove than a certified stove since there’s less engineered control over combustion in the first place.

Safety and Installation

A double barrel stove is still a solid-fuel combustion appliance, and the same basic rules that apply to any wood stove apply here: adequate clearance to combustible walls and materials, a properly sized and installed stovepipe and chimney connection, a non-combustible floor protector under the stove, and a carbon monoxide detector in the space. Because barrel stoves are typically homemade rather than a tested, listed appliance, there’s no manufacturer installation manual with tested clearances to fall back on — clearance and installation should follow your local fire code’s default requirements for unlisted solid-fuel appliances, and it’s worth checking with your local building or fire department before installing one, especially in an attached structure.

FAQ

How does a double barrel stove work?

Two 55-gallon barrels are stacked and connected by a short stovepipe. Wood burns in the lower barrel; the upper barrel captures heat from the rising flue gases and radiates it into the room instead of letting it escape up the chimney.

Can I cook on a double barrel stove?

Some people use the flat top of the upper barrel to keep a kettle or pot warm, similar to a wood cookstove’s warming surface, but a barrel stove isn’t designed or tested as a cooking appliance.

Can you burn coal in a double barrel stove?

No. Coal needs a grate and dedicated underfire air supply to burn properly, and standard barrel stove designs don’t include either.

Are double barrel stoves EPA certified?

Generally no — most are homemade from a drum and an add-on kit rather than a manufactured, tested appliance, so they fall outside the EPA certification process that applies to new stoves sold commercially.

How much does a double barrel stove cost?

A barrel plus a commercial add-on kit typically runs a few hundred dollars — significantly less than most manufactured wood stoves — though total cost depends on the kit, stovepipe, and any additional materials like a floor protector.

Reference: Hearth.com forum discussion on secondary combustion in double barrel stoves

Hi, my name’s Eugene Duke and I love sitting by my fireplace reading a book and sipping on an adult beverage. Do you have a fireplace in your house? I’ll help you figure out the best type and style of fireplace for your home.

Related