I had been using a blower we found in the greenhouse to get the fire in our wood-stove roaring, but then I realized that it already had a purpose! In the greenhouse! To keep the greenhouse warm in the winter I want to both absorb as much heat during the day and store it in things such as the pond and other high thermal mass materials and also insulate the greenhouse at night to keep in as much of the heat as possible. Our greenhouses are double glazed, meaning they have two layers of the plastic sheeting that covers the outside. Apparently this is actually a great way to insulate a greenhouse, and if you can get a nice amount of air between these two layers, then all the better. So we are trying out blowing up the greenhouse.
It is apparent from the holes that were already present in the inner layer of glazing and the fact that there are blowers in every greenhouse, that this was something the previous owners already were already doing. Hopefully this means that it will work!
I’ve been doing a ton of research about heating and insulating the greenhouses. This post from Midwest Permaculture seems awesome and has great information about things such as TMV and R values of different materials which is super useful.
THERMAL MASS VALUE BTU/Sq. Ft./degree F.
- Water 63
- Steel 59
- Stone 35
- Concrete 35
- Brick 24
- Sand 22
- Earth 20
- Wood 10.6
R-Value Measurements (hr°Fsq.ft/BTU)
- Fiberglass glazing- single layer R = .83
- Glass double layer R = 1.5 – 2.0
- Polyethylene Double 6mil film R = 1.7
- Glass triple layer 1 / 4 “ air space R = 2.13
- Polycarbonate 16mm triple wall R = 2.5
- Polystyrene (styrofoam) 1 inch thick R = 4.0
I need to check them out some more and read up on Midwest Permaculture
And then there’s always THIS
This is Jugtown 