Backyard Aquaponics
A place to discuss aquaponics

Stuart that all makes sense and well worth trying.

Using a propane gas heater in the same way wouldn't have the starting problems but I don't think it would produce anywhere near the same efficiency as the rocket stove.

It gives me something too think about and have a play with and see what happens.

Thanks

It depends on what you mean by efficiency. You could have the propane heater inside the GH in which case the efficiency would be 100%.

Do you mean cost effective?

Yes I meant outside the greenhouse set up in the same situation as the rocket stove it would have a very minimal effect, just the convenience of an easy start up over the initial lighting and possible drawing problem with such a long flue on the rocket stove.

If the propane heater was flued correctly and all fumes exhausted from the greenhouse it would be far better than running anything externally.

Joblow,
I'm looking to heat my greenhouse using a compost pile and hydronic circulation. The pile will be outside and I will pipe the water into the GH. It's a permaculture concept or at least one I discovered while reading a permaculture book. I'm yet to decide if I heat the sump or air. I'll work it out when the thing is built.

It's actually how I came to AP. I was looking at ways to heat the GH cheaply and have some thermal mass as well. Add fish, grow plants and here I am.

Cheers

Hi Carbonfarmer,

I think it was Porter that posted something on using compost in a wheelie bin that was very interesting, I had a quick look on his thread but couldn't find it.

From what I remember it used 2 wheelie bins exchanged regularly to keep the heat on going.




Stuart,

The first Youtube clip below is the sort or thing I was thinking of, I know anything inside the GH would be more efficient but you couldn't run a rocket stove inside a GH, so if I went with a rocket stove it would be outside, if I went propane I'd be looking at running it inside.

What is now going through my head is a combination of both the Youtube clips below. A horizontal flue running the full length of GH with a copper coil around it pumping water through PVC thermal barrels.

That way the GH would be getting heat from both the flue and thermal mass barrels, I like the idea of the concrete slab above the barrels, that would be ideal for germinating seeds and raising seedlings during winter.

With the price of copper these days I wouldn't be joining any, I think one roll would be enough to cover heating a couple of thermal barrels. There's still a few things that need working out, what is the right size?, does it need to go the full length of the GH, controlling the maximum temperature and not allowing it to get too hot, how much water loss would be in the thermal barrels, would the thermal barrels without the flue running through the GH be enough? etc.

Remember we're not building a sauna here.

http://www.youtube.com/watch?v=FrWtlf_4ny4

http://www.youtube.com/watch?v=AbDMITAMLio

WHat is your target?

Stuart at the moment I'm leaning towards a copper coil, pumping water to PVC barrels and either propane or a rocket stove to heat the water.

I might just build a small rocket stove and try some 12mm copper coiled around the flue and have a play with it and see how it performs and then work out if it's worth going ahead with anything bigger.

One of the things that needs addressing is that if you had a power outage or the pump stopped for any reason overnight what sort of problems would that cause?

Would a 12volt back up pump cover that problem, and how would you connect it into the setup?

Stuart at the moment I'm just running all options through my head.

Have you looked at a grain burning pellet heater, you feed the hopper with grade 2 stock grain (not for human consumption) and it can heat for up to 30 hours.

May be a bit of overkill?

No I haven't, I do know about them but I'd completely forgotten, but I'll now look into them.

Thanks for the reminder Continuum

You can do the same thing with a rocket stove and wood chips.

If you where really clever you could set up an arindino thingy to run it.

It looks like it's out of my league Stuart, I built a couple of crystal sets as a kid and then progressed onto building a Dick Smith chirping cricket and that was as far as I got with electronics.

That is more than I have done although Kudapucat is going to help me wire some sensors and data loggers up.

Maybe you could also do a googlesearch on Walipini. Those are basically greenhouses partly buried in the ground. It creates (amongst other things) a thermal buffer - keeps warmer in winter, and cooler in summer. That way maybe you could avoid active heating. (P.S.: reading about Walipini's (Walipinii?) is what in the end brought me to this forum....)

Have you bought the GH yet?

The triangular ones are really good for small GHs because they are so easy to insulate and only use materials that let a lot of heat out where they need to be (ie the glass or plastic).

Torut:

Thanks Torut, I know the Walipini greenhouses, digging doesn't happen here anymore, that stage of my life is well gone, the only digging I do now is in my CornFlakes Plus my wife would have a few things in the garden she'd like dug before any hole for a GH.

And I could think of nothing worse than digging a very large hole while being nagged at.


Stuart:

I haven't bought one yet and had one lined up a while back and took too long to decide and it was sold, I can get the pictured GH pretty cheap if make up my mind or it will go the same way.

As you get older procrastination becomes part of your life, so I'm still looking.