The way nature works never ceases to amaze me. In the first winter of growing year-round I had never scratched my head so much…. really! Shocked and bewildered on how the heat could stay in this 10’x12′ structure with nothing but plastic between my plants and winter in Ohio. Everything from how much sun we receive to how much water is in the rain barrel can make up to a 20*F difference. A very important design factor that helps with the heating and climate for the plants is the fact that to enter the greenhouse you have to walk through a potting shed that is well insulated. Not having a door that opens directly to the winter in garden zone 5b makes a huge difference. My friend Glenda up in zone 3 did an experiment on this topic that I will link to later in this blog post.
In the video above I share with you a peek inside my greenhouse the first year with a gas propane R.V. heater we recycled for our heater. The heater was $25 on ebay and my electrical engineer ( AkA Hubby) added some duct work cost around $20. If that heat should fail we have an electric heater from Walmart ($40) with a floor fan to circulate. The electric heater is on a separate thermometer to kick on if the gas furnace goes below 50*F. The benefit of using an R.V. heater is if we lose power the furnace can run on a car battery.
If you have any additional questions concerning the heat source we use please leave a comment and I will do my best to find an answer for you. Happy Growing!