Heating The Greenhouse Rocket-Style… The Adventure Continues

 In Alternative Fuels, Built Environment, Design, Featured, Gardening, Greenhouse, Permaculture Projects, Retrofit

blog book banner

The Rocket at the end of day two

The Rocket Mass Heater is now functionally done. After installing a proper chimney, it really hums!

I have now fired it four times for about an hour to an hour and a half to drive off any remaining moisture in the cob (I should have done this months ago) and the bench is just starting to show signs that it is retaining heat. Once the greenhouse is completely sealed up with thermal curtains* installed we will be testing the rocket to see how long the thermally charged mass bench will keep the greenhouse above freezing. If we are successful we will be working in the greenhouse as early as March this year without fossil fuels to keep the space warm.

Initially the rocket was not functioning properly because the chimney was not tall enough. When a chimney is placed around a building, all sorts of strange low and high pressure zones form around the structure due to wind blowing the building from various directions. For this reason the rule of thumb is to project the chimney at least 2 ft. above all surfaces (usually roofs) within a 12ft radius. It is also advisable to have a high wind cap which ensures that no mater where the wind is coming from there is always proper draw from the fire. Here is a great explanation of chimneys and high wind caps: http://www.woodheat.org/wind-chimney.html

Rob and Ashley looking pretty pleased about the project!

The last remaining step to complete the rocket is a render coat which we will apply once we have warmer conditions. The render coat is simply a protective layer with a finer finish applied to the outside of the cob bench to increase its durability.

*Thermal curtains are used inside the greenhouse along the glazing to reduce heat loss at night. They can be bought commercially, or you can use any insultative material, for example a blanket or construction tarp.

Below is a video that we produced showcasing the construction of the rocket mass heater.

Recent Posts

32
Leave a Reply

Please Login to comment
22 Comment threads
10 Thread replies
0 Followers
 
Most reacted comment
Hottest comment thread
20 Comment authors
Rob AvisMicJackieRocket Mass Heater Workshop at Groundswell - Verge PermacultureThomas Russell Recent comment authors
  Subscribe  
Notify of
trackback
Rocket Mass Heater Workshop at Groundswell - Verge Permaculture

[…] Heating The Greenhouse Rocket Style  […]

Thomas Russell
Guest
Thomas Russell

Thanks for all the advice however I am going to tear it down and try to start over as I cannot get the smoke to go outside it backdrafts into my green house. Horizontal pipe is about 30 feet horizontal then straight up and out the top of the greenhouse with a cap. still no luck. Bought a double barrel stove hooked it up it works just was given 2 100 pound propane tanks will follow a video on utube and make up to three of these units. Then I hope I can heat for about 10 to 11 months… Read more »

trackback
Rob's Modified Walpini | Verge Permaculture

[…] would build a rocket mass heater with a giant thermal storage bank within the space. These heaters are not perfect, but they […]

salvador
Guest
salvador

I’m in Mexico and perlite is non existent. Is there something else I can use insted of perlite?

George
Guest
George

Thanks for the reply. Do you know of any suppliers of refractory brick in the Edmonton area?

george
Guest
george

great video guys. I’ve seen some that use fire clay instead of refracted brick. Would this method give the same result??

Peter
Guest
Peter

To Thomas,

The best thing to do is put some 3/4″ vertical strips of wood on the flamible material and cover it with a tin sheet (the kind used for roofing. This provides an air space behjnd the tin which disperses the heat. Also the tin roofing will not burn.

Mary
Guest
Mary

This is GREAT! We are in Edmonton and looking at living a bit further north. We are thinking of combining this with the underground gardening idea, though it is a bit tempting to include this in a cob constructed house.

Thomas Russell
Guest
Thomas Russell

Please use the email I have listed as it is more convenient to use than this computer which does not work 1/2 the time. I am Thomas Russell dam near 70 and am fighting cancer at present. I have built a rocket stove in my greenhouse and it is within 6 inches of the UV poly and the laminated gothic arch beams . How do I protect the same for the intense heat put off from this barrel I am using refectory concrete so I know that will absorb a lot of the heat but I cannot afford a fire… Read more »

Carter Murtaugh
Guest
Carter Murtaugh

Greetings from Florida! I’m bored to tears at work so I decided to browse your site on my iphone during lunch break. I really like the information you provide here and can’t wait to take a look when I get home.

Kenneth C Young
Guest
Kenneth C Young

I love your idea of these Rocket Stoves.I was wondering as in the video you have via the link below could a Rocket Stove be build with the idea of having a thermostatic control system taking heat from for example the bench storage whenever needed,you have set up which joins the Rocket Stove. There would be for example in my case a duct system leading from the Rocket Stove bench storage area which would be in an insulated outside shed to my trailer where I could use a thermostat to adjust the amount of heat that I would want in… Read more »

Bill Greene
Guest
Bill Greene

I am building a greenhouse this summer and would love to build a rocket stove for it. Could I get some drawings or measurements on your design?

Michelle (Verge)
Michelle (Verge)

Bill, the best resource for plans comes from two places. 1) The Rocket Mass Heater Book Written by Ianto Evans (http://www.rocketstoves.com/) and from our friends at the Dartfield Earthship in British Columbia. The folks at Dartfield have done a masterful job writing and easy to follow manual on how to build and design one of these beauties. They also have a set of plans for sale as well. You can tell that they are engineers, I mean that as a compliment!

John
Guest
John

Great video! One question: Why is the barrel not also insulated with earth? Seems like it would just add more mass for the heat to be stored in and the barrel stack would not get so hot to the touch. Could you please explain this? Thanks!

Michelle (Verge)
Michelle (Verge)

John, Thanks for your comment, Rob Avis here. The barrel is best left mostly exposed for a couple of reasons. 1) This is when the system transitions to a low pressure system. As the gases pass over the heat riser into the barrel the heat radiated from the barrel reduces the temperature of the combustion gases thus shrinking them and helping creating the pull that keeps the draught going. 2) The barrel provides quick heating to the room where as the bench provides long term heat release. If the barrel was covered with cob the heat would take much longer… Read more »

Tanner
Guest
Tanner

Great video, very interesting and informative! Especially liked the continuous video of construction and the joke at the end 😛 hope you’re both doing well!

Dustin Bajer
Guest
Dustin Bajer

Great video Verge and DirtyCraft!

Mary
Guest
Mary

Very impressive! What square footage is there in the greenhouse, and is it open into anything else? From the looks of the movie it is attached to the side of another building. Sorry, I haven’t done my homework, where are you located? Just wondering how far north this will work. Thanks again!

Michelle (Verge)
Michelle (Verge)

The GH is 200 square feet. There’s a blog about it here http://vergepermaculture.ca/blog/2011/01/09/how-we-designed-our-solar-greenhouse/… although it is a little old & needs updating. We are in Calgary, Alberta, Canada.

Martin Reinhard
Guest
Martin Reinhard

Hey guys this looks good, What You guys need is a Mr. quick split from www. willowcreekforge.com.You can order it online. It was featured on the Dragon’s den December 5, 2012.
This kindling maker is ideal to make small pieces of wood for your rocket stove.
I took a class with Ashley on Heather last year
cheers Martin

Andrea
Guest
Andrea

Love it!! Simple natural heat exchanger =)

Hart Wichern
Guest
Hart Wichern

Thanks for posting this. Is it possible to draw exterior air to feed the rocket. As it is designed at present…while the rocket is burning,a lot of the interior heat is drawn into the rocket.

Michelle (Verge)
Michelle (Verge)

Yes it is possible and it simply requires running a duct into the top end of the feed tube. We did this in a different RMH that we installed last year and it works great.

Joey Hundert
Guest
Joey Hundert

This is really great guys!

0

Start typing and press Enter to search

Hope, Knowledge & A Plan...
NEW! Verge's first online Permaculture Design Course starts April 14,2020. Our next in-person PDC starts on Sept 26, 2020. 
Learn More! 
Close