Wednesday, January 9, 2008

Pit Greenhouse plans

Happy New Year!

I'm soooo very excited! It's the YEAR OF THE GREENHOUSE!!!

I've been busy planning my pit greenhouse. I've spent many hours researching greenhouses over the past couple years.

Originally I was going to purchase a geo-dome. However, I decided they were unacceptable because they were a) pricey for the size, b) wouldn't be considered "permanent" enough for my satisfaction, and c) just didn't look like something I wanted to look at everyday. I loved the shape but the construction seemed, tacky cheap. I'm not really knocking the geo-domes, they have their place and I think they are brilliant but overall, just not, well, pretty or permanent enough.

So, then I spent a year or so looking at other options and found.... none. At least nothing that I considered appropriate for our weather, wind, temperature fluctuations, and my absolute desire for self-sufficiency. So, I gave up for awhile and then stumbled onto the idea of a pit greenhouse. Now, that I can do.

I've come up with a statement and list of objectives for my future greenhouse:

To build a pit greenhouse for year round production of fresh organic produce (including lemons, limes and possibly dates).
  • It is important that the greenhouse be as self sufficient as possible.
  • It should use solar and thermal as it's primary sources of heat and cooling.
  • Secondary sources would come from a small propane tank (that I already own) and heater to be used very sparingly as well as passive heat/cooling from water barrels. Electricity would be used for fans in the summer and lights in the winter.
  • It should be built as a permanent structure and with that in mind should be aesthetically pleasing and fit in with the current surrounding architecture. (ie: brick, ranch style).
  • There will be a wall and roof covering the steps for protection during winter months.
  • I plan on having a small patio just outside the door for potted plants and chairs during the warm months.
  • I intend to build it for less than $5,000.00 by using our own backhoe, labor and cement blocks. This is my projected total cost to include running electric water and propane lines.
As soon I get my desktop back from the shop I will scan my plans and post them. Though I have to admit, I still have several versions of plans. They are all pretty much the same though. My basic plans are as follows:
  1. 10 or 12 x 24 give or take a little.
  2. Dug down 6 feet, layer of chicken wire, and a 1 ft layer of pea gravel. SE corner will have a sump pump area dug down about another foot or two.
  3. Walls will be built of cement brick on N side up to 10 ft. S side only 5 ft. Cement walls will have rebar added and filled with cement for added strength. I'll probably cover the outside of the walls in insulation. And possibly the inside N wall with that silver bubble wrap looking insulation.
  4. Angle of roof should be approx. 45 but still researching the perfect angle for our location.
  5. I'm hoping to find triple or quad glazing. I haven't decided what to use for glazing supports, either poly pipe or ? but I think wood is a bad idea and I don't want to use treated wood. Possibly cedar, I don't know.
  6. I need enough black plastic barrels to cover the whole N wall. I will fill them with water for passive heat and cooling. I'm thinking of somehow linking them all up with tubing so in the winter, instead of shocking the plants with ice cold water I can use the preheated water from the barrels then refill them after watering.
  7. A large fan in the W wall and solid and screen door for the E wall. I'd like to make the fan solar powered but really I know nothing about solar power, yet.
  8. I'm going to spend the money to purchase organic top soil, peat moss, growing medium. I've thought about our topsoil and it's not organic and even the weeds look starved.
  9. I'd like to install a misting system in the ceiling for the summer months.