dome, di dome, dome

     I’ve been looking at a lot of greenhouses.  I’ve decided my favorite ones on the market are “Growing Spaces,” created by a couple in Colorado who began their venture 20 something years ago.  These greenhouses are beautiful.  They are essentially dome structures, well built and well insulated.   I assume the majority of people who own these greenhouses are using their indoor pool of water as their thermal mass to store the sun’s heat.

    So, I was recently reading one of the articles on their blog and someone asked what winter temps the dome would be able to endure if one were to install solar water heat exchangers.  They answered that with the solar hot water addition, the inside of the greenhouse could maintain temps 50 degrees (Farenheit) warmer inside than out.  This is truly significant when you’re talking about growing plants and veggies.  Think you can’t make this any better?  But you can.

    Regardless of whether you feed the hot water into piping underneath the dome or back into the indoor pool itself, using PCM in the hot water tanks can store the heated water for longer periods of time and you could probably downsize to smaller storage tank as well.

    This is how it would work.  Your solar hot water heat exchanger heats the water during the day when the sun is out.  I’ve seen solar collectors that follow the direction of the sun to receive optimal light.  But as soon as the sun goes down and the water cools, there is some kind of backup generator that switches on or other alternative heating source to keep the water warm in order to heat the greenhouse.  If you put PCM of an appropriate temperature  into the storage tanks, it will conserve the sun’s heat for a longer duration.  And to top it off, you’d be saving money and fuel due to less usage of your backup heating source.  Again, totally advertising here, but this basic idea of utilizing PCM to store heat is feasible with ANY solar hot water system.

    Check out these geodesic domes.  Wish I had an extra $15,000 laying around…

    This doesn’t have anything to do with greenhouses although I’m sure you could use some of his micro-houses for the purpose of a greenhouse (heat storage would still be an issue).  This guy’s clever.  Goes to prove, you can pretty much recycle anything.  

Derek "Deek" Diedricksen featured in the New York Times gives a tour of his “gypsy junker”.