walls as thermal mass for greenhouse

Any time someone says, "YOU CAN ONLY GROW VEGGIES THIS LONG IN YOUR CLIMATE", I want to cringe in horror.  I seriously want to be able to grow in my cimate year round.  I have a psuedo-design for a greenhouse using a rocket mass heater except the thermal  mass is the half wall and floor forming the bottom half of the greenhouse.  I am thinking that by branching the heat produced into smaller pipes ( i.e. a 4" pipe from the stove feeds 8, I/2" pipes embedded in the floor or wall)  that it may be possible to channel the heat through the floor and walls leaving the open space in the room for it's intended purpose, and could be made quite beautiful minus the heavy mass that usually encompasses a room.  Any feed back is greatly appreciated as I intend to endeavor on this project come spring and could use some input as to materials and how to's, thanks!!  Mind you I said a PSEUDO design.  We all know what that means.

Woodmyst,

Solving the heat in winter time problem with a rocket mass heater is a good idea.
The plants will still need longer hours of light to produce well, not only day length but also light intensity plays an important role in plant life.  A year round greenhouse that requires heat will also require extra light, and that can be expensive.

Good luck!

Instead of heating air, which loses it's heat rapidly, I would recommend using the rmh to heat water, and circulate that water through the wall and floor.

I agree with Shawn, in winter, you not only need the warmth, but light as well, so you will have to find a way of turning a short daylight time into a long one.  And the further north you live, the more critical this becomes.

The light issue is another whole ball of wax.  I'm looking at solar panels or a windmill or both.  I don't expect to throw a builing up in a month and be growing this year.  I thoroughly expect at least 2 years  but it is imporant to me to be able to run this puppy off the grid.  A lot of the commercial growers use metal halide and high pressure sodium depending on the stage of growth.  Hydroponic is an option as well.  I have to figure out exactly how much wattage will be drawn and all that rot first and the more bells and whistles the higher the draw.  I really want to get the heating issue taken care of this year so that I can at least extend the season this winter and start some seeds in the spring.  Thank you for the input it is appreciated.  That water Idea sounds cool.  Are you talking sort of geo thermal?

If you're worried about both light and heat, why not plant things that require less of both?  Peas, carrots, lettuces, and spinach would be great winter crops, plus if you for whatever reason, can't light the stove on one night, some or most of your crops might live through a bit of frost.
What about running the vent pipe under the soil itself?  Put some insulation underneath to channel the heat upwards, and 12 inches of soil on top. I don't know if that would be too heavy, might need some bracing.  Dig into the ground, and build the stove a foot or two below grade to make running the vent easier.

Running vent through a cob wall would probably work ok, but my concern is this: heat rises, and the place it is needed the most is down at the soil level.  Having that heat in the wall would be ok, but I just think it would be MOST effective under the soil, keeping the roots warm, which is what a lot of plants like anyway.
You could easily dig it up and move it, but once you embed it in a wall, it's there for good!

adamtheha, That sounds like what will probably happen this year.  I like the idea of it not being so permanent at first, at least until I get things the way I want them and then proceed.  I was hoping to keep tomatoes all winter but that would require the ambient air to be warmer plus the additional lighting.  Of course the additional lighting would also provide some heat but doesn't run 24/7.  That's where the thermal mass came in. to keep the air warm for the more tender veggies and for me. LOL!  I'll just move into the greehouse all winter so I can smell the dirt and eat fresh tomatoes!  See y'all in the spring.