How to heat a greenhouse?? Heating your greenhouse with a 24,000 BTU mini split isn’t just possible—it’s a smart move that solves a lot of the problems greenhouse growers usually face in colder months. Here’s why it works and why it’s better than old-school heaters:A 24k BTU (about 2 tons) mini split is powerful enough to heat up to 1,000–1,200 square feet, depending on your insulation and outside temps. Greenhouses lose heat quickly because of all that glass or polycarbonate, but mini splits ar