Neil Reed

Satamax, great find thanks that answers my questions quit well.

Glenn that is the question I should be asking isn't it? But it seems to me that with the intake pipe being heated it would draw primarily from that....possibly decreasing the draft from other sources...

Thomas the thing is the air is not warm, it comes in and gets warm from the heat radiated from the mass heater which means it is cooling the air that you warmed. I was saying why not heat it up before it gets in the house and use it to move the warm air around at the same time.

I was wondering what you guys think of this. As the Rocket Mass Heater burns it needs air, this air generally comes in through the doors and windows, i.e. draft, since air is going to come in no matter what and we actually need the air why not use it. Below is attached a rough drawing of a 2" pipe coming from the outside, the air is heated as it passes by the bell and exits the pipe over the bells top. The advantages are that the air coming in to feed the mass heater is now hot rather than cooling down the other areas, it should increase warm air circulation and might even create a positive pressure inside.

Like the input thanks guys. Here is what I am thinking would be a good combination for the Base of the RMH, I am using 4.5"x9"x1.25" firebrick, and the cement board in 1/2" thick. I decided that the extra 1/2" of a second cement board would not impact the design so I added it to further protect the sub-floor. An air gap between the two cement boards partially open at the front and open at the back going up between the mass and the house wall. Perlite on the base up to the J tube. From the advice and experience you have given this should give plenty of protection.

John, yes that was my concern as I have seen videos of what you describe but was concerned about the closed in nature of it in the home.

Thomas, thanks that answers my question quite well, I was considering putting a concrete board under it but raising it up sounds like just the ticket.

I am new here and I am sure other questions will come up. I will post my design when completed, I use a 3d design software and rendering in simlab so I know what I am doing before hand. Attached is a quick concept design I did.

I too was thinking about this and was planning on placing a metal screen around the barrel between 1 and 2 inches away, maybe capped. It will still be there but rather than try and hide it it would accent it a bit . check home depot or lowes for metal screen and there are several decorative patterns.

Looking into building a rocker stove mass heater in a standard wood frame construction home. The question is how much insulation is needed under the burn tunnel to protect a sub floor? In addition to the fire brick used to build the burn tunnel I was planning on having a second layer of fire brick as a base, would a few inches of a sand/perlite , be the proper amount of insulation?

Thanks for your responses.