All the books say draw the air from the outside, every greenhouse I have
seen draws from the inside. The blowers sold for inflation are made to go
on the inside and use inside air. I have never had a problem and all my
greenhouse use inside air. If you are not having problems with water and
things growing between the layers, I would not worry about it.

Pat

"David Jewell" wrote in message
.. .
I put a greenhouse up this summer and am confused about a point and was
wondering if anyone could answer this one for me. I currently inflate the
greenhouse with air from inside the greenhouse but have been told I should
be drawing air in from the outside.

With drawing the air from the inside I am thinking that the bubble will be
warmer and give me better insulation but I am concerned with the issue of
water collecting in the bubble. With drawing air from the outside I am
thinking that the air will be a lot colder and thus not so good for my
orchids.

Any advice would be greatly appreciated.

Dave (Ontario, Canada)