I hope someone can help me! I used our dog kennel to make a cold frame last year, which I've described on another thread:
The thread "My Dog Kennel Greenhouse!"
in Greenhouses forum
I'd love to heat it this winter, and see that using drums or barrels of water is a good way to go about doing that. I'd like to use 30 to 50 gallon drums. I was told that painting them black will make them heat up even more, which is great, but I have NO idea how many barrels or drums I'd need to help keep the green house a little warmer during the winter. It's 6 feet wide by 10 feet long, and about 8 feet tall. I'd prefer to use 30 gallon drums because they would take up a lot less room on the ground.
Anyone know how many I should use? Also, do the drums need to be covered with a lid? I was hoping to set boards across the top to use as a table to hold more plants. Would that be enough of a cover or should they be sealed shut? I don't want it super hot in there, but a little heat would be great. Thanks for any help!