BCSS - Forum

It was warm enough at the weekend for the vents to open!

Hi Mike, I don't know about others, but when I see my vents opening in the Spring I get very exited at the thought of the new growing season lol, and I have been growing foe nearly forty years old. Cheers

My vents also opened at the weekend, always an exciting sign of Spring!

and at what temperature these automatic openings open because it's still early ?

About 20c internally.

20 ° it's low to have a greenhouse opening
30 ° would be more reasonable

That is an interesting comment Richaud from somebody living in a slightly different climate. Are you in the south of France? Most UK growers would certainly want some ventilation when the greenhouse was up to 20C and that is the lowest temperature at which most vents will actuate. I have a mixture of manual and auto vents because in the winter I would tend to ventilate the greenhouse at even lower temperatures for a few hours if the weather was dry, just to reduce humidity levels inside the greenhouse.

Yes Terry I'm in the south of France (Le Cannet near Cannes)
now it's 0°C in the morning (3° in the greenhouse ) and 10° at 12 h
But with the sun ( not often right now because of the maritime inputs ) in the greenhouse 25-30° and the vents stay closed

It depends ... on so many things.

At this time of year I'll certainly want ventilation if the sun is strong enough to push the temperature to 20C (and there's no other reason it would reach that temperature in February), because I want to keep the humidity down (getting easier every day now) and not overheat the winter growers.

In summer, I wouldn't necessarily want to ventilate on days that only just scrape to 20C in the greenhouse, but on sunny days I'd have everything possible open or off because 14+ hours of high sun through unshaded glass is brutal.

Then there is the variety of ways people have to measure temperature, which effectively makes comparisons completely pointless.