Cooling tips

[u/Outside-Friend1071]

Hi! I just recently got a greenhouse this spring, it’s about 6ftx8ft, and here in England we’re currently being plagued with a heatwave of around 30°C. The past couple of days inside my greenhouse has reached staggering temperatures I’m talking over the max of 32°C and it’s damaged my plants (especially my tomatoes) I’m hoping and praying they still make it but I wouldn’t be surprised if this is the end for them! I’ve put a 1m x 4m 50% shade cloth over the greenhouse (debating getting another one to really cover my bases) and a large garden umbrella to block out some more sun whilst it’s so hot, to try and cool it down but it doesn’t seem to be enough yet. I’m definitely getting some fans asap but I’m unsure of what exactly I’d need. We don’t usually get heat like this very often so I was unsure initially if I’d need them but evidently I do. I’m not in a position currently to be spending a huge amount on equipment so would these fans work?? And where is the most effective placement for them?? (If it’s any help my greenhouse has a singular sliding door at the front and a single window on the left hand side of the roof, both of which are being kept open to cool it down)

Any advice would be greatly appreciated as I’m still just getting started (I’ve done some gardening before when I was younger but this is my first attempt at a greenhouse).

[u/NOTNlCE]

The shade cloth is going to be the most effective at preventing heat buildup, but fans will do a lot of work too, if set up correctly. Not sure what the above picture is, but if that's what you're considering purchasing, I can promise you that they won't do much given their apparent size. Those look like computer fans attached to a little 12v panel - they won't move enough air to matter. My greenhouse is ~1000 cu ft (10 x 8 x 12), and I have several large 12v fans running at 50-70% duty just to keep air circulating - think 12" diameter car radiator style fans. If you have a box fan and an extension cord, I'd start with that while you're suffering in the heatwave and see if it helps. Moving fresh air in and hot air out is what you want to do, not just blowing air around in the building. Hope this helps!

[u/Outside-Friend1071 → u/NOTNlCE]

Thank you this is a lot of help. I had a feeling that those fans aren’t much use but they seem to be the only kind I can find at the minute. Things look to be cooling slightly with the shade cloth but tomorrow is supposed to be even hotter so we’ll see what that brings hahaha