Rocket heater with added thermal mass for small mountain hut

I built the cedar hut in 2011. It is approximately 5.4m long and 3.6m wide facing south and well insulated. It has a gable roof so the loft space is usable as a micro mezzanine. The heater idea came from a Japanese YouTuber about 10 years ago. All I have done is taken it inside (after extensive test burns outside) and added the thermal mass.

It is important to note we live in a humid subtropical Köppen climate classification: type Cfa

This rocket heater thermal storage idea allows for efficient heating within a single hour of rockety burning, focusing on heating fire bricks. Once these bricks become too hot to touch, they store ample thermal energy, ensuring a cozy environment for several hours without the need for constant attention. This not only enhances safety but also grants the freedom to engage in other activities, knowing the room remains comfortably warm. After the burning phase, covering the heater’s horizontal and vertical openings prevents ash dispersion, leaving behind a safe, fire-free zone while the hot bricks continue radiating heat effortlessly.

A typical burn will go through 2.5kg to 3kg of bamboo or hardwood in approximately 1 hour. Bamboo typically creates much more ash.

The thermal mass will give off a good amount of heat for 3 to 5 hours +

The internal temperature taken at about 1500mm AFL typically gets to around 20° plus while it’s 3° outside. The mezzanine/loft would be uncomfortably hot and therefore I would fit a downdraught ceiling fan if I had electricity connected.

I’m still experimenting and tweaking, but aren’t we all😊