Getting ready for an early spring

I don't know what the weather will do but I am hoping to have an early spring inside of my greenhouse. My goal is to start my seeds in the house on January 2nd. I'm thinking that by the time they are ready to plant I will be able to have the greenhouse warm enough for them. I believe I've figured out a way to cheaply make a double wall of plastic. If I place a grid of 1 1/2" pipe over the current layer and then fasten it down and cover it with a second layer. I should be able to gain some insulation value with minimal expense. I'm also planning on making an insulated door. I'm hoping to do this with my father over Christmas break.

Since I last updated this blog I was able to finish insulating the end wall but I haven't sealed it with foam yet. I did move in some compost, it still needs to be mixed in with the rest of the dirt, and clean up the old plants. The garlic and onions were still grown last time I worked out there but I haven't checked them lately.

Effects of the fan, insulation, & more

Unfortunately I forgot to turn on the rollover feature of my thermacron so the data never got recorded. In the mean time I was able to pickup some 2 inch foam insulation from HomeDepot, which was cheaper than Lowes. Last night I was able to install the insulation in the back wall. The plan is to fill in the cracks with the spray foam to seal it up really good but I want to get all of the pieces in first so that I don't waste the can of foam. I'm planning on insulating the end wall Wednesday night and hopefully sealing it up on Sunday. I'm also hoping to be able to make an insulated door on Sunday which should really help seal things up.
Until then I've stuck a small utility heater in there that is rated at 1300w. It is set on the lowest setting and is on a timer that turns on and off every half hour during the night so that I'm sure it will not run to much. The heater blows onto the fan which blows onto the plants. Hopefully this will help keep them warm and happy, but not scorched. It seemed to work well yesterday. I'm hoping to post the temperature data from that on Wednesday night.
I've also purchased two dark green 30 gallon trash cans that I plan on putting water in to help collect heat during the day.