Ventilation

[-pat m]

Ok � Ventilation is very important I wasn�t in the forum until January and as such kept my doors fully shut through the winter and suffered from lack of air flow, On previous threads.
I know now how important ventilation is � I have loads of stuff pretty advanced in the poly tunnel now and wondered if I should keep the doors open all night now the evenings are warmer?
I have my greenhouse also in the tunnel and that is heated separately. Is it better to shut up (generally when the sun goes down when I put the chickens away) or leave open when night min temp is 5+ and day temp is in the teens? Any advice appreciated.

Regards

Pat

[Two_Sheds]

The evenings aren't warmer, are they? We are still getting frost here most nights.

I open my greenhouse between 8am and 4pm, then close it up for the night

[-pat m]

Hi two sheds thanks for the response -The last two nights have been cold but for 5 nights prior to that it was +4 - +6 Forecast for my area:

Fri. NightClear Sky
� Min: 1�C34�F
� Sunset: 18:17
Sat. Night
� Clear Sky
� Min: 6�C43�F
� Sunset: 18:19
Sun. Night
Partly Cloudy
� Min: 6�C43�F
� Sunset: 18:20

My point is does ventilation override heat retention in a poly tunnel? My greenhouse is shut up and kept at a warm constant heat all night and ventilated during the day – I am using my poly tunnel as a large garden and will be using my greenhouse as the place for more exotic heat loving plants.

Any advice appreciated

[bramble]

Pat, I have lots of seedlings in my greenhouse now. Its unheated. I open it up at about 9 o'clock and shut it up for the night at about 5.
Personally, I don't think its warm enough yet to leave the doors open.
Just my opinion.

[Two_Sheds]

Pat, it all depends what you've got growing in there. Not much will grow at only 5 C.
Additionally, plants like a nice constant temperature, not swinging between 15C and 5C

[-pat m]

Thank you both for your responses � I think I shall let the more constant heat win over ventilation � I hadn�t thought about Heat variances this is a worry for me even now at this time of the year - I am recording 25 degrees in my tunnel during the day with the main ventilation open (I have some more emergency ventilation for the summer.
Well I will start to close up in the afternoon until the warm evening arrive properly

Thank you both again

Pat