Rocket Mass Heater in my Greenhouse Complete

[David]

I just completed or 80% completed a 6 inch rocket mass heater in my greenhouse.  It is fantastic.  Here is a video:

https://www.youtube.com/watch?v=c_cfUSbRq54&list=UU2iOWdrhx-pLf...

[Jack Dunbar]

Hi David.

Nice videos. I can't wait to see the finished product. How big a Greenhouse will you be heating. Can you give us some info on your Greenhouse specs and outside/inside temps. How often do you have to feed it? How long does it take to get that mass up to a decent temp?

[David]

Jack,

I have an 18X20 hoop greenhouse.  The stove is just what the book says a dragon.  It needs to be fed every 30 to 40 minutes.  I do not have my bench finished and I have to add 12 feet of pipe because I'm loosing too much heat out the vent.  I My outside temps are in the 30's and I have to burn 3-4 burns and that last me several hours.  I don't know what it is doing when I've gone to bed, but for now I'm running a little buddy heater on LO to supplement it.  I left it at midnight last night and when I went in this morning at 8a it was 60 degrees in there.  I will get more detailed data when my bench is done and report back to you.

David

[Tim Radcliff]

Great videos David. I'm thinking about building one of these parallel to my hoop house (not enough room inside). I was thinking about enclosing the "stove" and placing a radiator on top of it to heat the water, and return it to my sump. People are saying not to run AP water through metal, though. My second thought would be to run PEX through the mass, and returning it to the sump. Does the mass get hot enough to heat water?

[David]

The mass doesn't get hot enough to heat water, but the barrel does.  The problem is that you would have to constantly stoke the fire.  One of the downfalls I'm discovering is that I have to get up and go out and stoke the fire every 30 to 40 minutes for 2-3 hours straight.  Next I am going to build an straw igloo compost heater outside the greenhouse and let that heat the pex pipe filled with water.  Much less work.

David

[Harley Mayer Jr]

I like your idea i am working on my green house plan on heating with a double barrel heater. Will use some wood and some paper logs. I have built my paper log press to make a 4.5 by 4.5 by 12 inch log . Have tested it i can burn 4 pieces of wood when they get low i put 4 paper logs 3 pieces of wood and three more logs and it can burn for about 8 to 10 hours. I will have a fan set on a timer to come on every 30 to 45 minutes to stock up the fire then turn off.The paper logs work allot like charcoal the just smolder. My bottom barrel gets up to 500 degrees top barrel get up to 250 to 300 degrees.Gonna use my top barrel as my water heater to heat my grow beds.

 

[David]

How did you build a paper log press?

David

[Harley Mayer Jr]

I used a 5 inch piece of square tubing built a funnel table and it uses an air cylinder to press it. Me and my daughter can press about 4 logs every hour to an hour and a half then we just let them dry in the garage on the concrete floor.Gonna heat my 24 x 50 green house that i built out of reclaimed windows and poly carbonate on the roof.  

[Robert C. Wood]

I have seen on youtube people using wood pellets and an automated feed system for their rocketmass heaters, With it being automated you don't have to get up in the middle of the night to stoke the fire.

[David]

I saw that as well, but do not have the space to retrofit mine and the welding expertise to make it.

David