Bubblewrap?

[daemondamian]

I have read several times that bubblewrap is a good insulation material for GHs in winter.

Does it work in reverse in winter- helping to cool the GH
or does it's insulating properties only work in retaining heat in a GH?

[littlefrog]

I don't think it is a good idea. It wouldn't keep the light out, which is where most of the heat comes from, and it would only prevent the internal heat from exiting through the walls. I think it could only get warmer in the summer, not cooler.

[daemondamian]

Originally Posted by littlefrog

I don't think it is a good idea. It wouldn't keep the light out, which is where most of the heat comes from, and it would only prevent the internal heat from exiting through the walls. I think it could only get warmer in the summer, not cooler.

Thanks Littlefrog, I thought that might be the case.

[Ross]

To expand on Rob's message (which I totally agree) several things are wrong. First it's only a so-so insulation. Second, to be effective it must be on the same side of glass as the heat (insulation slows heat migration - not cold migration) therefore you'd have to place it on the outside of the glass for summer use. Third, it is very fragile and would break down and blow away if on the outside in the sun. You are better off to have lots of big fans and perhaps the cooling of water evaporating from wet pads in front of fans (swamp cooler).

[daemondamian]

Originally Posted by rsfrid

To expand on Rob's message (which I totally agree) several things are wrong. First it's only a so-so insulation. Second, to be effective it must be on the same side of glass as the heat (insulation slows heat migration - not cold migration) therefore you'd have to place it on the outside of the glass for summer use. Third, it is very fragile and would break down and blow away if on the outside in the sun. You are better off to have lots of big fans and perhaps the cooling of water evaporating from wet pads in front of fans (swamp cooler).

Thanks for the input rsfrid,
I had about 3 layers of bubblewrap over my hobby GH in winter/spring which helped heat it up a fair bit because it trapped the heat from the 150 watt metal halide and 2 45 watt compact fluroescent lights. I was thinking about it on the walls and ceiling of the little lean-to I am planning on using for the winter but I guess I will have to make the effort to remove it when the days start getting hotter

[Ross]

Actually there is a double-wall fiberglass product designed to do what you want. It has UV-resisting chemicals in the outer layer and insulates as well. Not sure what it is called or where to get it, though.