This week was the week all the parts arrived. The new relay board works fine. The misting pump motor still sometimes resets the micro controller when it kicks on but I’ve been able to deal with that rare occasion via software. I will not use a DC pump again, I think that’s the problem anyhow, poor shielding and grounding on a DC pump.
The new plant tray works great. The pneumatic piston is reliable and doesn’t leak saving the life of my air compressor. The load cells still seem to be working and it tares every 5 mins. I have the tomato seedlings in it now.
The weather was very hot and humid (for Nova Scotia). Temperature was 28c with 81% humidity. The misting was working, but it made the greenhouse supper wet and I was worried about fungal diseases on the tomato plants. I built a little tunnel tent structure (opaque white poly) around my greenhouse intake vent and put the misting in there. That cooled the air before being blown into the greenhouse. I also made a large shade that out of white poly that I can deploy and cover the whole glazing roof. This limits light, but at this small stage the plants don’t really need that much light so I think it will be ok.
I had to rewrite pretty well all of the controls programming. The serial between the arduino mega and the laptop is unreliable. So I put all the mission critical stuff into the arduino. I then had the logger program automatically reset on the laptop is logging stops. So far (4 days) it seems to be working.
I built my eversion based vent door, it works ok but needs higher pressure air than I anticipated.
I might pause this because I have an idea for the glazing insulation. The shade overtop of the glazing was actually really easy to deploy. Since the glazing is inflated, you can pull the edges of the shade down and the glazing yields but pushes back keeping it taught. Even in the wind I had no trouble. Granted it hasn’t been that windy, but I think I could make an external R-20 blanket with fiberglass batts that I can deploy by hand. Lots easier than the eversion through glazing to setup. This is just to test the hypothesis that the greenhouse can run all winter with no heating, it doesn’t have to be practical at commercial scale yet. The first step I think is to make a big sheet of full poly that can cover all the glazing and work out the best method of moving that across the glazing.
Sun Aquasystems 