The GH is connected to the house with a 6 ft window. There is a fan to exchange air to keep it warm on cold night. On a sunny 40f day the solar thermal gain puts heat back into the house. It will gain an avg of 50f over ambient air temp. The framing is scrap metal. The door is an old shower door. The aquaponics and seed starting chamber also have a lot scrap. The fish tank is in the basement to regulate temp of water so fish can make it through winter. I just planted the beds on 3/15 with brassicas, lettuce, spinach and chard.



The entrance with some toms out for a run in the sun


The seed starting chamber is basically a garden window. There is a door to keep in warm for staring seeds in Feb. It will keep the same temp as the house except for sub 20f weather. Then it will drop 10 deg below house temp. There are 2- T8 lights for supplemental lighting and to extend light for 16 hr days in early spring. (60 watts total for 4 to 6 hrs a day)


All closed up for cold days and nights.


I have a seed heating mat that is for germinating peppers and other seedlings that like plus 80. It is flexwatt tape that reptile breeders use with a jumpstart thermostat. (20 watts/ft for 40 watts total it is on and off 50/50)


There are many subjects about heating a GH, supplemental light in winter, starting stubborn peppers seeds on here so I hope this helps. This GH/AP/Seed Chamber functions for about 20/mo. It give me all the greens, tomato's and a few peppers 9 months a year. The rest is frozen for winter use. It starts 500 - 1000 plants a year for the garden and AP beds. The system is shut down from Nov to mid Fed for cold weather.