It's been COLD. Below 0 more nights than not since before Christmas. It's been so cold that when it warmed all the way up to 38 F one day last week, it felt positively balmy. You know it's been cold when 38 feels toasty!
The day time highs have been in the 20s on a warm day, and there is snow on the ground. On a sunny day, the greenhouse heats right up to mid 70s. On a cloudy day, or a snowy day, it gets up to 40. That's not bad for solar gain on a day with no sun and the outside temperature in the 20s, but I want a greenhouse that's warm enough for the 3 pots of Moringa oleifera who don't like it colder than 40. I want it warm enough for the rose geraniums and lemon verbena.
Starting in late February, it will need to be in the high 70s to germinate tomato and pepper seeds.
I am building a
rocket stove mass heater, something I learned about in 2003, when I took a cob building class with Ianto Evans and Linda Smiley of
Cob Cottage.
Most people build rocket stoves with collected materials, so I made a tour of the junk yards, the re-store, my garage. I called the oil change places and mechanic shops until I found a barrel. I gathered brick from my garden. I read and re read the
book , read the whole
permies.com wood stove forum. I would lie in bed in the morning before getting up, at night before sleeping, imagining how the air would flow, how it would go together. I tore up the floor in the back third of the greenhouse. Pavers, dirt, tarp, rock, tarp.
Here I am using my materials to plan. I understand the idea, and have got the right dimensions and proportions in mind, but spatially, it's a puzzle. Always has been. Playing with building blocks I would disassemble and rebuild a thing several times, because I could not visualize the completed thing, had to see how it went, then go back and add the needed pieces, once I discovered I needed them. Here is that same thing again. Build it part way, and then discover what it was I did not yet understand. Luckily, the experts all say to build a "mock up" exactly what you plan to build, to see if it will work, so I guess maybe I'm not the only one who doesn't get it the first time.
Yesterday, I leveled a pad and began. At the end of the day, I had mortared the feed hole
and the burn tunnel and the bottom of the heat riser. The stove pipe is just resting on top of the bricks. It was a good stopping place. I wanted to let the mortar set up. The sun was down, and it was getting cold.
Today had lots of puzzles. The heat riser needs insulation, then a barrel. The silver tube will hold the insulation, but the space between the insulation and barrel is critical, and I could not see how the fumes would get out if I set the barrel on the bricks, and if I did not set the barrel on the bricks, then what would hold it up?
The clean out walls are in place. Whew! And with my black circle the diameter of the barrel, and my cut up pieces of measuring tape, I measured the space where I hope the fumes pass into the clean out and thence to thermal mass.
At this point I think I'll raise the barrel up 4 inches by setting a course of bricks on the side, and I will build that course to the outside, leaving space for the fumes. Three improvements. Extended the heat riser, increased the cross sectional area for the fumes exiting the barrel, and created a support for the barrel. Yay.
