I'm a previous indoor grower looking at starting a grow in a greenhouse. Looking at about 8 by 12 greenhouse. What will I need in ways of lighting, etc. I'm in high desert of southern az where we do get 20 and 30 degree temps. I know laws. Just looking at what I would need to keep warm, wattage of lamps for supplemental, etc.
I'd stick to hids just for the free 'heat' ..lol ensure you can open both ends of the greenhouse for max venting and a big big fan is very handy in hot summer days unless you grow in pots that you simply drop outside for keeping warm I add extra soils as an insulation protects against heat too say the temp gauge ..lol good luck
Do you want to flower in the green house year round Or Clone to flower in the green house? On the farm we used the greenhouse with flood tables for vegging to about a foot tall then set them in hoop houses for flower, Spring, Summer and Fall with light deprivation to keep the schedule. The winter was for processing cloning and prep for the coming spring season. The crop was just to small over the winter months in the greenhouse and cost went up for heating and and supplemental lighting, Hoop houses, which were String light with LED bright white bulbs and 1000W hid in the green house to supplement that 18 hours of light for vegg mainly early spring and late fall. Heating was with a Pellet furnace and a bit of ducting. Big question for lighting. Do you have neighbors that will complain about lights at night? Greenhouse? Polly panels, Double GH plastic or glass? Panels are expensive and glass is breakable. My choice is Double GH plastic, needs replaced every 4 to 6 years. Arrangement East to West for all day sun coverage. Keep your exhausts fans and intake louvers low on the end wall to keep the river of air moves through the plants and not over them.
My Buddy started last year whith some inground heating. A bunch of spaghetty rubberhose on a hose manifold and a waterheater. He had trouble w his wife and never finished. But is was supposed to work, so that he can run a light dep house in the Wintertime. There was also a big 325K Gas Heater in the Greenhouse ( about 100 foot long)
I have a similar project. I have 4 water heaters so far, 3 circulation pumps,.. I'm a plumber and collect the working equipment for my own projects. Radiant floor heating is on the list right after it goes up.