On Dec 28, 11:12*am, phorbin wrote:
In article , says...

There are devices that operate windows automatically using the heat build up
for power. I'm sure you can find them at a greenhouse supply. *You might

For example,

http://www.leevalley.com/en/garden/p...43&cat=2,43224

We are hoping we can use the ones we have in the current greenhouse
but glass maybe too heavy for them.