I have a central boiler with a maximum 500,000 BTUs. The firebox is 5'x4'x3' and the 400 gallons of water surround the firebox. I am only heating the ghs with this stove. I am in zone 3 and the coldest morning of the winter is often near -30 and only rarely -40, but I am quite sheltered from the wind and we usually have enough snow for some insulation around the bottom. Yes, I have poly on both the inside and outside of 4" walls. A 30'x30' pyramid is 900 square feet and the cubic feet is found by multiplying 1/3 of the 20 ft. height. So the volumn of air is much less than a building with vertical sides. The 51,000 BTU figure is something I can work with. I'll see what the 8' finned tubes are rated at or what a plentum in a furnace blower is. A was going to try the first one with manual ball valves with a bypass and the second one I was going to try to make it thermostatic and automaticly controlled with a pump or zone valve.

Here on the Central Coast of CA, I have mine outside on my west facing porch, it's much hotter than 104 most of the time, however this year seems to be screwey, it's a lot cooler than it should be. Anyway, I have to shade all my plants with two layers of shade cloth and still they get sun burned if they get too close to the cloth. I also have multiflora outside, I have it in a drip tray and water from both above and below. I also let it sit in the water, not advisable for other hoyas, but this one seems to be the exception. It also seems to want to be fed more often, it's a fast grower for me, it's also the one the aphids like best.

My first Hydrangea is now in the ground for more than 25 years. At this point, I keep it for sentimental reasons only. It's gotten so THICK with canes that if I wrap it in my usual cage, I have to get everything so tight in there that I think I may actually be suffocating the plant. I've not had good luck overwintering it in recent years. This past winter I didn't even bother with it. If I were you, I'd consider taking a cutting or digging out a portion of your sentimental one and essentially start over. It would indeed be the same plant, so you could keep your sentiment. But I can understand sentiment. I should get rid of my first Hydrangea, but I'm not. For a long time I would cut back the old canes completely to the ground in the Fall. I'd only leave canes that had shot up from low points on the canes or from the crown. They would have grown all summer and would end up giving me great flowering the next year. I'd have very long stemmed flowers, too, that I had cut. The big problem with this technique is that you end up with weaker stems than you would otherwise and next summer they'd be weighted down to the ground with their flowers. I've found that, for my zone, I can usually prune as hard as I want up until about Fourth of July, just to be easy to remember, and not hurt the flowering potential for next year. After that, the buds start setting for next year and you start running into that problem. (But then I've cut some "nikkos" back to the crown in the Fall and on some I'd get great flowering and on some I'd get none. Do I really understand this? NO.) So, here is another method for you to consider to keep it smaller, at least in height. Another thing I've experimented with is to prune all the wimpy growth completely out and just end up with a few stout canes over time. This was interesting, but you end up with an artifical looking Hydrangea and the few stout canes start looking rather strange. But with this technique, more or less, you could develop a plant that wasn't so crowded. I don't know though. I wish I could help you more. I'd like an answer to the question you have, too! Hay

I don't think he literally meant it was freezing! Call me nuts but I run our dehumidifier in the basement almost all year long. I find the extra heat put out by it is enough to temper the air to a comfortable level. In the summer the basement will stay in the mid 60's with no AC down there but of course we need to run the dehumidifer in the summer. With it running the temp will hover in the upper 60's and its very comfortable. If I were to try to dehumidify the basement using our AC it would be way too cold to be comfortable. In the winter we heat the basement with duct work from our furnace. Again, with heat from the furnace I can keep the basement in the mid 60's which is not too bad, but we also have a whole house humidifier which we really need for the portion of the house above the basement. The extra moisture from the humidifier will condense on our basement glass block windows (and I can imagine it would do the same behind the studwalls too on the concrete walls) to counter this I run the dehumidifer in the basement during the winter. Besides keeping the humidity to a reasonable level it also adds a little heat and will keep it in the upper 60's. You may be able to tap into existing ductwork for added heat and add returns as well. Adding insulation will help too if it isn't already there.