Help me to decide

I have a green house with the poly cover 16x24. A hailstorm destroyed the cover but I received insurance money for a new cover. Here is my dilema:
In Minnesota, it goes from winter to summer. The greenhouse gets so hot early but not warm enough to put plants outside during the night. I need to vent it. Back window is not enough venting. Should I fix the pvc poly greenhouse and suffer through the hot temp. or should I buy a small greenhouse with stiff sides and roof vents?Is there a way to vent poly on the roof? I love my greenhouse but the heating up is such a problem. Any ideas?

Heat is a problem in the summer, I removed half of my roof, attached hinges and now I can raise it about 8" which really cuts down on the heat .
It may be more of a job on your GH.
I made the change 1 1/2 years ago, you may find it if you look back in the post.
I am now doing a big upgrade, remodel, adding 16' and will also have vent windows all along the top of the new roof.

mdeano, I'm totally new at this (I'm getting a house that sounds like yours in about a week) so forgive me if I'm off base.

One of the things that I saw on one of the larger GHs near my home and ordered for my own is roll-up sides - just basically cranks that roll your poly to whatever height you want up to 3-4', I believe. If you're interested - http://www.growerssolution.com/page/GS/PROD/GA/RollUp

HTH!

Thanks for the link, Pagancat, lots of good info

Glad to help. That particular company is local for me. I had the chance to participate in a couple of co-ops with them as well.