I wanted to start this thread as it seemed that AJ's excellent First 80 Plants in Greenhouse thread was getting hijacked with some wonky greenhouse tech talk- so let's get our wonk on in this thread! I originally thought this would apply more for those of us in northern latitudes, but I think unless you were cursed to live in tropic climes, this will apply for most everyone.
As Carol linked in the Specific heat table water is a wonderful thing- an excellent substance for thermal mass storage. You don't have to get all technical in order to use it either- as I stated, what I've done in the past is simply fill a few huge 60 gallon plastic trash bins with water, which, once I toss a chunk of plywood on top of, serve a secondary purpose as a table. While the scientific term is formally 'specific heat capacity' I'm more able to visualize what we're talking about by referring to it as 'thermal mass-' fortunately for me, the terms are for the most part interchangeable. Another part of the equation is thermal inertia, or volumetric heat capacity- that's different than thermal mass though and it's a bit more wonky than even I want to get here, but feel free if you want to chime in on it, I'm all ears.
Pam provided a great link to a Passive Solar Greenhouse white paper which is perfect in outlining the basic principles we're talking about here. Thank you muchly for that link Pam, it's pretty much exactly what I've been working on in my head for a long time now. I've been building a passive solar house along the lines of the Enertia Homes in my head for years, and the design for a greenhouse fits in along the same parameters- proper design ahead of time will make for much longer growing seasons and FAR less cost in the long run.
I've been VERY lucky- the property I've just bought already has a fairly modest (about 10' x 10') greenhouse on it that has been plumbed for gas and electric and it already has been wired for a thermostat that controls a small gas heater as well as an exhaust fan in the ceiling-
That picture is facing directly West so the Southern sun is to the left. That's great since the greenhouse will obviously be getting a lot of southern exposure. But I've always wondered- why in the hell do people glass in the North side of a greenhouse? I will be covering up and insulating the North wall, at least, and insulating the kickers as well. I'm not going to get too deep into modifying the existing structure though, this coming fall/winter I will hopefully be tearing it down and pouring a pad where this one sits so that I can start building a REAL solar greenhouse. Unfortunately, the only thing they did right in building this one was placement-
Around here, you can't get much better southern exposure than that.
Anyways, I guess I wrote a lot. Heheh. I'd sure be interested in other folks' thoughts on the matter- solar or any other forms of heating, as well as personal experiences and pictures, of course!
As Carol linked in the Specific heat table water is a wonderful thing- an excellent substance for thermal mass storage. You don't have to get all technical in order to use it either- as I stated, what I've done in the past is simply fill a few huge 60 gallon plastic trash bins with water, which, once I toss a chunk of plywood on top of, serve a secondary purpose as a table. While the scientific term is formally 'specific heat capacity' I'm more able to visualize what we're talking about by referring to it as 'thermal mass-' fortunately for me, the terms are for the most part interchangeable. Another part of the equation is thermal inertia, or volumetric heat capacity- that's different than thermal mass though and it's a bit more wonky than even I want to get here, but feel free if you want to chime in on it, I'm all ears.
Pam provided a great link to a Passive Solar Greenhouse white paper which is perfect in outlining the basic principles we're talking about here. Thank you muchly for that link Pam, it's pretty much exactly what I've been working on in my head for a long time now. I've been building a passive solar house along the lines of the Enertia Homes in my head for years, and the design for a greenhouse fits in along the same parameters- proper design ahead of time will make for much longer growing seasons and FAR less cost in the long run.
I've been VERY lucky- the property I've just bought already has a fairly modest (about 10' x 10') greenhouse on it that has been plumbed for gas and electric and it already has been wired for a thermostat that controls a small gas heater as well as an exhaust fan in the ceiling-
That picture is facing directly West so the Southern sun is to the left. That's great since the greenhouse will obviously be getting a lot of southern exposure. But I've always wondered- why in the hell do people glass in the North side of a greenhouse? I will be covering up and insulating the North wall, at least, and insulating the kickers as well. I'm not going to get too deep into modifying the existing structure though, this coming fall/winter I will hopefully be tearing it down and pouring a pad where this one sits so that I can start building a REAL solar greenhouse. Unfortunately, the only thing they did right in building this one was placement-
Around here, you can't get much better southern exposure than that.
Anyways, I guess I wrote a lot. Heheh. I'd sure be interested in other folks' thoughts on the matter- solar or any other forms of heating, as well as personal experiences and pictures, of course!
. Damn you got some space there!.
I lucked out a LOT- 5 acres of oceanfront, with 5 very active volcanoes across the water! And yes, lots of space to grow on as well- with three producing apple trees in their own fenced in yard to keep the moose from eating them all up!
