Lisa Brick

thomas rubino wrote:Hi Lisa;
The working temperature of copper is 1400F-1700F It starts to break down at just shy of 2000F

So, yes, copper will work.  But is it a large enough vessel to hold a riser and leave room for air movement?

Your planned pipe run of 26' with two 90-degree bends is larger than a 6" system can push, especially with your hottest air radiating away outdoors.
A 6" system can push 30' of horizontal pipe.
An 8" system will push 50' but your copper barrel may not have enough room for an 8" riser.
You mention wanting to have the entire core outdoors and only the heat pipes indoors.
This is not a great idea, 90% of your heat will blow away and there will be very little left to heat your greenhouse.

I suggest Building a mud room outside your greenhouse and enclosing the entire core to save all the heat.

Super idea re the mud room as it's right next to out back door so would be ideal! Might need to reduce my run so because as you mentioned the tank I have won't have the height for an 8" system.

I'm also considering feeder and chimney outside of greenhouse as I'm only planning a small 5ft x 13ft area right next to the house. Existing house will be one wall, then rammed earth north wall with feeder & chimney on the outside running to 26ft of pipe and 2 90° bends. My question though is about the heat riser drum. I have a plain copper drum which was once a hot water cylinder. Has anyone ever used copper instead of a steel drum? It is a bit smaller as well but as I only have a small area to heat I am hoping to scale everything down to suit. Can't find any information on using copper.
Thanks!

I'm also struggling to source borax (no luck on the site previously mentioned as they don't offer shipping to rep. of Irl). I'm not sure anyway if my plan will work as I'm wondering about using sheep's wool underground in a similar way to John Hayatt's insulation umbrella in his passive annual heat storage concept. As mentioned before, wool is so cheap and readily available it would be great if it works. I'll rinse it clean, pull out any bad bits, and hopefully get some borax on it but I'm not sure if it will work in such compressed conditions with approx 3/4 ton per sqm weight on it. I also might need to try using some kind of breather membrane instead of plastic to cover it and I'm sure I'll come up with another few alterations before i get started. I'm hoping to try it out on a solar greenhouse next year so we'll see how it goes but I'm more hopeful now after hearing about using it as an insulator under a pond.👍

Terry Byrne wrote:Hello to all Permies!!

I have/possess and just recently reread the John Hait book [2013 edition]  Passive Annual Heat Storage. I have been doing further research, looking and it seems to have just died. I came across a Paul Wheaton article which I had also seen a few year ago, link below.

https://www.makeitmissoula.com/2014/05/passive-annual-heat-storage/

Does anyone know what has happened to this idea, to John Hait, ... is there anyone still pursuing this? Are the houses that have been built still being used, still functioning after all these years, according to the initial plan? To me these seem ideal to RMHs.

Any and all info would be much appreciated.

Terry[

Hi, very late to the party but have been milling around an idea for a "self-heating" home for the last few years. Am just restarting the design process after reading John Hait's inspirational PAHS. I originally wanted to build a passive solar greenhouse into the mid-section of our hill and later a home above it which would be heated by the greenhouse and then naturally ventilated to cool but I think we are ideally placed to build something based on John Hait's design principles. But then I also have the same questions! Where did the research go? Are there any working examples still in operation? Will all my time & effort result in something which has to be abandoned and rebuilt with current petrochemical reliant materials/techniques? It seems like it could go either way for me as we are in Ireland so we don't have a massive temperature difference between the seasons but we do have water water everywhere so will be a massive challenge to exclude completely. Anyone willing to offer insight into real life examples would be greatly appreciated.