Greenhouse heat sink
The greenhouse project got started on Monday and the greenhouse heat sink is completed. Our greenhouse heat sink is comprised of 120 yards of 3 inch screened rock. It is surrounded on four sides with 4 inches of styrofoam and is covered with 2 feet of soil. There are 6 feet of foam that insulate the rock, the heat sink, and the soil over the heat sink that is inside the greenhouse.
In this picture the foam is 4 inches thick and 4 feet tall. There is 6 inches of rock in the bottom of the hole and we have begun covered the first 10 lengths of the perforated drain tile. Three feet of rock will go over the top of these lengths of drain tile.
The second set of drain tiles
In this next picture there is three and a half feet of rock inside the foam and the second and final set of drain tiles are ready to be covered with rock.
Once covered with rock we covered the rock with a 3 mil barrier fabric that will allow water to pass through but will exclude the soil. This is important to prevent the rock from being plugged with dirt and rendering the heat sink useless.
Once all the barrier fabric is in place it gets covered with 2 feet of topsoil. The soil was compacted with the track hoe and then leveled in preparation for the greenhouse assembly.
The last two feet of foam
We had a small mishap and breakdown in communication. As a result we are going to have to put in the last bit of the Styrofoam with the aid of a trencher. In a future blog entry I will cover the lessons we learned during this process and the mistakes we made. Hopefully you can learn from us and not make a similar mistake.
Watch us build the greenhouse heat sink
So far there are 5 videos in this YouTube series and I expect to have two more before we begin assembly of the greenhouse. You can watch the videos of the heat sink build on my YouTube channel. Here is the first video in the series.