When I started planning my tiny house move off-grid, one of the first questions I faced was simple but critical: How will I heat it?
I knew what I wanted. Firewood as fuel, a self-feeding system, no electricity, low maintenance, and something foolproof that wouldn't require constant fine-tuning. I needed a stove that would keep the house warm while I was away during the day and through cold winter nights without waking up to add fuel.
After researching, I came across a YouTube channel called David S, whose rocket stove design caught my attention. It ran on both pellets and firewood, and I found his approach inspiring. I decided to build my own version with some modifications, and this post walks through what I learned along the way.
Why a Rocket Stove?
Rocket stoves tick a lot of boxes for tiny house living:
- They burn extremely hot, which means efficient combustion and no smoke from the chimney
- They're compact and don't take up much floor space
- They're straightforward to build using steel and welded pipe
- They lend themselves well to gravity-fed, self-feeding fuel systems since fuel is loaded from the top
The basic principle is simple: fire burns in an insulated combustion chamber, the hot gases travel through internal channels, and then exit through the chimney. Because the burn is so efficient, there's virtually no smoke.
My Build: An Overview
The stove is built from 12 cm × 12 cm square steel pipe with 4 mm walls. The feed tube is 240 mm, the burning chamber is nearly three times that length, and the total stove width is 640 mm with a height of 820 mm.
The burning chamber is wrapped in 50 mm of calcium silicate insulation, which makes it keeps the combustion temperature high enough to burn off all the gases.
Fuel is fed from the top, and I use an adjustable pellet basket that lets me control the fire intensity. By narrowing or widening the basket walls, or raising and lowering it, I can dial in the flame size. When I first ran pellets without the adjustable walls, the top of the stove glowed red hot, so this addition was essential.
Challenges and Solutions
Building the stove was a learning process. Here are the main problems I encountered and how I solved them.
Problem 1: Thermal Mass Didn't Work as Planned
My original idea was to add thermal mass (stones inside the stove) so it would retain heat after the fire went out. In practice, there wasn't enough mass to make a meaningful difference, and the stones actually acted as insulation, blocking heat from radiating into the room. Most of the heat went straight up the chimney.
Solution: I removed the stones and replaced them with flat iron radiation bars that radiate heat outward into the room. This worked far better.
Problem 2: Too Much Heat Escaping Through the Chimney
With a relatively short chimney (150 mm diameter, roughly 2.5 meters with one 45-degree bend), a lot of heat was being lost up and out.
Solution: I installed turbulators inside the exhaust channels. These are simple contraptions made from an iron rod with a square plate and four lengths of chain hanging down. As smoke passes through, the chains create turbulence, which slows the draft and allows more heat to transfer into the room rather than escaping. I was skeptical, but they worked remarkably well.
Problem 3: Difficult to Control the Burn Rate
Rocket stoves run extremely hot once they reach operating temperature, and controlling that intensity was tricky, especially with firewood.
Solution: I added a cap/hat for the feed tube when burning firewood. This forces air intake to come from below through the dedicated outside air supply, rather than pulling air from the room through the top of the feed tube. Combined with a damper in the chimney and the turbulators, this gave me much better control. When burning firewood, I typically run the damper at about 15% open.
Problem 4: Excessive Air Consumption
In a tiny house with limited interior volume, a rocket stove can pull a serious amount of air. Without a dedicated air supply, this would be a real problem.
Solution: I designed the stove with a dedicated outside air intake. Air enters from beneath the floor, travels up through a gap between the outer wall and the insulated feed tube, and flows down into the combustion chamber. There are access points for cleaning the ash tray and channels. The air path has several 90-degree turns, and while I wasn't sure it would draft properly through all those angles, it works well as long as the feed tube cap is in place during operation.
Daily Operation and Fuel
I run both pellets and firewood in this stove. Pellets are easier to control since I can adjust the basket size, while firewood requires more management with the damper nearly closed to prevent overheating.
I installed a thermometer on the chimney and aim for a smoke temperature of around 150°C. This tells me the stove is burning efficiently without losing too much heat up the chimney or risking creosote buildup from too-cool exhaust.
What I'd Change Next Time
This was my first build, and overall I'm very happy with it. But if I build another one, here's what I'd do differently:
- Go smaller. I'd use 10 cm × 10 cm tube instead of 12 × 12. In my 25 m² home, even the smallest sustainable fire raises the indoor temperature a little per hour, which means running it all night would overheat the house. A smaller stove would allow for a longer, gentler burn.
- Add adjustable turbulators or additional dampers. The current setup is a compromise: with one turbulator, firewood lost too much heat up the chimney. With two, pellets run great but firewood still burns a touch hot. Being able to regulate the draft dynamically would solve this.
- Consider a water heating system
- Experiment with a longer exhaust path (up-down-up-down) to increase the radiation surface area and extract even more heat before the gases exit.
Final Thoughts
This was my first rocket stove build, and I went in without experience in sizing or designing heating systems for small homes. Between studying David S's videos and prototyping, I got to a design that works surprisingly well.
If you're building a tiny house or looking for an off-grid heating solution, a self-feeding rocket stove is absolutely worth considering. It's affordable, efficient, compact, and with the right modifications, genuinely practical for daily use.
If you have questions about any part of this build or want me to go deeper on specific details, leave a comment or reach out. I'm happy to help.
