So I’ve fallen off the horse on these blog updates, but here’s a brief summary:
The tomatoes are all still alive, though I did have some for of leaf disease or something hit two of them hard. All the leaves got brown spots, but now their new leaves are ok. I think they will recover, it may have been related to poor humidity control at night before I had automatic vents.
The greenhouse is pretty much totally automated now. I built pneumatically operated doors for the intake and exhaust vents. They seems to work quite well, reasonably tight. This allows for fine temperature control and humidity control. If the humidity rises too much I can open the doors for a few minutes and then close them. I actually had to debounce that because in the morning and evening it would be constantly opening and closing the doors as the temperature crossed the venting threshold. So now I say no more than one door open or close every 3 mins. Working so far. The irrigation system is working fine, except that once my air compressor stopped (maybe triggered an overheat switch?). Anyhow it started back up but not before it irrigated a bunch extra. Not a big deal but now I have dual redundant air compressors attached to the same line so it doesn’t happen again when I’m not right there to fix it. Hurricane Fiona knocked out the power for a few hours but I was able to run everything off the generator so no issues there.
I built a blanket that rolls down over the glazing at night. Looks good so far I just need to test the actual R-value. It’s nowhere near what I eventually want ( I estimate between R-3 to R-10) but should be good enough for this winter with the heater (1500 watts). This winter the goal is only to measure light capture and determine if it’s enough for tomatoes in January. The blanket rolling system is me with a crank made from a piece of rebar which is not automatic. I have some motors but I’m not sure I will use them in this application. When there is snow I will have to be there regardless to sweep it off before roll up and down, so maybe it doesn’t save much time to automate.
Sun Aquasystems 