Our New Hot-House – A Two Year Project – A Three Part Story

Part 1 – Construction of a large indoor work space for seedlings and early transplants.

With learning how to prepare for the growing season, a number of projects have been implemented on our farm. One of those projects was to build a small “hot-house”; a lean-to styled building that we built on the South-west end of our equipment shed in 2012. It was 20 feet wide by 7 feet high and 7 feet deep with a fixed 20 foot long bench along the windows. The Southwest facing wall had 20 feet of window glass about 3 feet high and a polycarbonate roof that allowed lots of light into the space. This is where we first tried to grow peppers and tomatoes. Since it was a small space, we created a removable shelving system above the bench with some steel tubing, allowing for a second row of planting trays to be placed above the ones on the bench. Inevitably, it was too crowded and with the low ceiling and it tended to be quite hot inside so we had to be careful not to fry the young plants on a sunny day. Of course, on a cold and cloudy day, we needed to supplement with a heating system, so we added a small heat exchanger and fan, pumping hot water from our outdoor wood stove to the hot-house to keep things warm and comfortable.

As we increased in vegetable production, our facility was becoming too small so we soon recognized the need for a bigger “hot-house”. So in the spring of 2015 we decided to expand. The plans were drawn up. Quotes were given. The materials were ordered. While using the existing hot-house last spring, we built the new one right over top of the old one at a size of 20x30 feet instead of 20x7. Once we had the new hot-house roof in place, we dismantled much of the old hot-house a few pieces at a time until all the transplants were moved out to the field. The new hot-house is built with a post and beam method with structural roof trusses and clear polycarbonate roofing to ensure the sunlight can get in. Inside, there are four raised beds, two of which are set up for experimental use, the other 2 are control models. The North end of the hot-house is insulated at an R-12 value for the first 8 feet (walls and ceiling) and a transparent separation curtain can be placed at the 8 foot mark for early season work, keeping the heat in a smaller space but allowing sunlight in. The walls around the hot-house are sectioned in approximately 4x8 foot panels with the first 2 feet at the bottom of these panels clad in weather resistant plywood and insulated to about R-5. A larger heat exchange system is in this space to allow us to continue to do early season work, the heat still being taken from our outdoor wood stove. We don't have any seedling shelving in the new space, so we will quickly realize the need in only a few weeks time. Spring is on the way!