Big Greenhouse Benches: Water Power!

This past spring we installed a new, larger, greenhouse on the farm. My intention is to have not only plenty of growing room for loads of sprouts the restaurant likes, but to also house the many kinds of vegetables we start from seed here each year.

The shell was erected a few days before our first seedling sale day in mid March. We didn't quite get the benches installed at that time, instead we had to use makeshift tables to hold our thousands and thousands of tomato starts.

Proper greenhouse benches are currently under construction.  Not only are they strong and beautiful, they are energy efficient!

I was brainstorming ways to reduce the energy consumption of a greenhouse (our electricity bill is already horrific) as well as help the environment.  Through my research I discovered a technique that uses stored water to equalize the temperature in a room.

Here's how it works: during the day the water (stored in drums in the greenhouse) heats up. At night it releases the heat, which reduces the amount of night-time heating required. Simple!

I purchased 32 drums, each can hold 55 gallons of water. The drums will be used as the base for the greenhouse benches.

To maximize the bench space, hours of schematic work was done.  They needed to perfectly hold the 17"x17" seedling trays, and customers needed to be able to get to the interiors of the bench easily during sales.  This created tabletops 6 trays long by 4 trays wide, 66" x 100" (with a bit of a overhang). Each bench will rest on 4 drums, and there will be 8 of those benches.

Ron Kinch (chef's dad), who is a retired civil engineer, came over and built the bench frames for us.  He designed a really great frame, keeping costs down, made from Douglas fir 2x4's and 1x2's.  They'll be topped with a durable and cost effective metal screen from the lumberyard.  That's a job for another day (yes, chef, another day soon).

The drums are not filled yet; they will require precision placement because once they are filled they are not moving.  It will be interesting to see just how well the stored heat idea works.  But in the meantime, we are enjoying using the space for our gardening classes, particularly my upcoming series of Winter Vegetable Gardening workshops.