thomas rubino wrote:Hi Adam;
Welcome to Permies and Welcome to the wonderful world of rocket science!
I'll try to answer your questions.
#1) I suggest an eight-inch core over a six inch.
The feed tube size on a 6" is very restrictive, an 8" has much more room for crooked wood.
An 8" will also require less tending than the 6" and produce more heat.
Yes, 55-gallon barrels work with 6 or 8-inch rockets.
#2) Yes, you can use brick or even flat rock for the piped mass it has been done before.
As you want your heat to rise and not go down and heat the earth, you will want to insulate under your brick tunnel.
Perlite and clay with straw added is a good option, sand is another. Pebbles are prone to rolling and might not be a good choice underneath.
Here is a new line of thinking for you.
You can create a bell with 1/2 barrels and not use a tunnel at all...
You would still need to insulate below.
A cob mix would cover the barrels.
#3) The volume of your tunnel must match or exceed the volume of the feed tube, the shape does not matter.
Sloping your tunnel is not necessary.
My questions are, How are you planning on using this greenhouse?
Is it for early starts and late-season finishing?
How cold do your nights get and how warm are you hoping to keep it inside?
Were you hoping to run it all winter?
Wow thank you sooo much Thomas for the wisdom and help!. We REALLY appreciate it!.
Yeah, I was leaning towards an 8inch system, but I was wondering if I'd have enough brick, but I don't wanna cut corners and want to give the greenhouse it's best chance to thrive, so 8 inch it is!.
As far as the piped mass goes, we were hoping to have it basically sit flush with the ground so we could have a couple 4x4 foot, 3 foot high raised beds over top with walkways between so we can get to the other side of the green house. (you can see in the pics how we've spaced the beds on the other side of the wall with approx 2 foot wide walkways in between). So basically it would be the RMH at one end, a 2 foot gap, a 4 foot raised bed, another 2 foot gap, another 4 foot bed, another 2 foot gap, and then a small 2 foot bed at the end with the chimney coming up at the back of the bed and right out through the roof. So thus the reason I was thinking of making a brick tunnel.
Oh and yes we plan to use perlite and clay the whole way on the bottom underneath everything. I was just thinking to add rubble, drainage roc underneath just in case any water ran into there during spring thaw etc.
As far as the "1/2 barrel bell" system you spoke of, I have not heard of that before and am not totally sure what you mean?. Are you saying to run out of the heat riser at the bottom and instead of into a brick or ducting "tunnel" then chimney, to go into a barrel cut in half?. I have not seen such a thing so am having trouble seeing it in my minds eye?. Is there examples or drawings anyone has done of this?. I am open to any and all ideas here.
Basically, yes we want to grow year round in it, as we are off-grid and trying to become totally self sustaining here, being that we are both on disability, and want to become free of "the system" etc.
Our weather here gets quite cold, we are basically near the dead center of British Columbia by Stuart lake, and last winter we had a few days that went as low as -30C (-22F), and an average of -15C (ish) (5 degrees F). We do have a friend who lives 2 hours away and he grows year round using hoop tunnels and big steel wood stove drums to grow year round, so we know it can be done. We plan to try it out this winter and see how it does, and may even add another 2x2 wood strips gap and add yet another layer of 6 mil poly to add another insulation gap. The goal is to eventually replace all the poly with that plastic greenhouse sheeting, but could only afford poly right now.
Oh and I'm not sure what difference this makes, but our ground here is maybe 6 inches of topsoil, and then it goes straight to a tan colored clay (basically like the background of this web page lol). So we have PLENTY of clay here, and it goes DEEP. Our frostline is around 7 feet here!.
Anyways, thanks yet again for the advice. I'm super interested in hearing more about the half barrel bell idea, as I am willing to go that route if we can make it work in the space we have. If utterly necessary I guess we could sacrifice having one of the 4 foot beds. Oh and we also plan to put an IBC tote up above the RMH riser if we have enough room, so we can keep the water warm through winter as well. :)
But yeah, any and all advice from anyone on here will not go unappreciated that's for dang sure!. We are picking the Perlite up on Tuesday, so hopefully we can button the rest of this greenhouse up very soon here!. The nights are already getting chilly here!. The race is on! lol.
Thanks again from:
Adam, Melinda, and Kyla, the Alander family! :) <3
