too much air passing through ?

[marialittlebzz]

I built a cold frame/ tiny green house out of poly sheets...It is waterproof but not air proof... I mean there is two layers of sheets, but air is passing in between and when the wind start blowing hard I can see that quite a lot of it is passing through. How bad is that?
frost is not really a problem in London, but we have chilly night around 2-3 degrees. I thought with two layers I will still get a good insulation, and is not aeration a good thing for baby plant?

[Protea]

I built a cold frame/ tiny green house out of poly sheets...It is waterproof but not air proof... I mean there is two layers of sheets, but air is passing in between and when the wind start blowing hard I can see that quite a lot of it is passing through. How bad is that?
frost is not really a problem in London, but we have chilly night around 2-3 degrees. I thought with two layers I will still get a good insulation, and is not aeration a good thing for baby plant?

ventilation is a GOOD thing for plants - stale, stagnant air encourages fungal diseases. However, a little air movement is what is required, you don't want gales or a proper draught so it depends on how much air is passing through! Difficult to know what to suggest as its not of standard contstruction! Do you have any really tender plants (that can't stand frost)? if not, then i wouldn't worry too much. Perhaps some gaffa tape on the corners might help!

[Two_Sheds]

the wind start blowing hard I can see that quite a lot of it is passing through. How bad is that?

I have the same problem with OH - the wind gets really bad

[Snadger]

I have the same problem with OH - the wind gets really bad

Well stop feeding him artichoke and split pea soup then!

[terrier]

I think what your doing, marialittlebzz, is creating a wintunnel effect, the chill factor created is probably worse than leaving the plants in the open and you'll lose any benefit from frost protection.

[marialittlebzz]

Actually, it is not as what you describe, maybe I didn't explain myself properly : the frame is entirely covered with a double layer of plastic, but some air manage to pass in between this two layers, creating a light breeze passing through.
So now the question is : how much ventilated a green house must be?