Greenhouse Korean-style heating

[elkhound]

 

[Magus]

That heating system has a LOT of uses!

 

[joel]

 

[joel]

Designed by Bill Wilson (MWP) and Kevin Kepplinger (HTP Farm)
Construction and Design Assistance from Heal the Planet Farm Team (All are Midwest Permaculture PDC graduates)

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Picture Summary of the building of a Greenhouse Rocket-Mass Heater Build and its use from January-March of 2016

We started the rocket stove build on December 30th. The high was in the 30’s, lows below freezing. There was plenty of frost in the greenhouse come morning.

Kevin and the farm-design team had poured a 4′ by 6′ concrete pad for us to build upon. The first step was to dry-brick the stove together to get a feel for how it all might fit. It didn’t take long before we had our basic design.

Here are two Sketches of the Basic Design

While we started to form the fire chamber, other members of the team began to dig the trench which was to become the thermal mass sink. The backhoe saved us about 20 hours of digging.

Located near the north wall, the heat rises, rolls across the top, drops as it cools across the south face of the greenhouse and moves gently across the floor to be heated once again by the stove and thermal-mass trench.

Back to the trench. It has been fully dug and now the river gravel is being shoved out of the bucket of the backhoe and layered 3-4 inches thick at the bottom. The thermal mass is built up from this.

One side of the 8″x 8″x 16″ concrete bricks are laid end-to- end against the insulated wall and then filled in with gravel to hold them in place and increase the thermal mass.

Then, a second layer of bricks is added.

The other side is done the same way with gravel filling in the bricks. Next goes the insulation on the bottom between the rows, then 3-4 inches of gravel, then the 8″ exhaust flue, then more gravel and a third row of bricks.

Here is a cross-section of how the thermal-mass trench is constructed.

A “T” is spliced in near the top so that once the pipe is buried in gravel, one can still access the interior for visual inspection or to vacuum out ash.

Speaking of the exhaust pipe, the 2-inch insulation board has be laid in on the floor of the thermal-mass trench, 3-4 inches of gravel added, and now the pipe has been assembled with a single screw holding each 2-foot section of pipe together. Remember, we are maintaining the 8″ flue pipe dimension (50+ square inches) throughout the entire system.

With the system mostly in place we couldn’t resist building a small fire to test it out. Even without a lid, once the fire was hot enough to heat the riser the stove began to rocket, pulling all smoke into the fire chamber. It Works…!!!

While tending the fire we started to fill the trench with gravel and observed how the cob was starting to dry out.

During lunch we let the fire burn out. You can tell from the burn pattern around the opening to the fire chamber how much hotter it is right there. From the picture you can also get a good feel for the size of the fire chamber. How many pieces of firewood like the one in the foreground can be added into the chamber at one time?