AutoVent - Temp setting?

[wonkey_donkey]

Hi,

So this is my first year with the GH, what sort of temp do people set their autovent's to?

i think mine is currently set to open around 19deg, which i suppose is a bit low.

So what's the ideal temp for it to open and to keep the greenhouse to?

I have no artificial heating btw.

tia.

[Capsid]

The vents respond very slowly and so it won't maintain a very tight temperature in the greenhouse anyway. Even if it opens at 19C it will rapidly get warmer. My greenhouse can get to over 40C even with a vent and bottom louvre. The vent's function is really to help with airflow, if you have trouble keeping the temperature down then it may be best to use some shading.

[wonkey_donkey]

Ah, that'll explain why it's been up over 25 deg's already this past week then.

So is it better to have it more open than closed then? ie leave it to open around it's current temp or to crank it up a bit so it opens later?

[Capsid]

I'd err on the side of having it more open.

[mrscorpio]

I fitted an auto window opener the other day. I followed the instructions - winding the piston so half the thread was showing either side of the nut. The problem with this was the window was now open at 14degs. Do you have to let the piston ( wax filling ) settle for a few days as the temp goes up and down ? I would assume it came out of the box warm and was lying on its side.

[Bigmallly]

If you find it opening too soon, wind the piston so that it closes the opener. Likewise if it is not opening & you want it to, wind the piston the opposite direction so that it starts opening. Do this until you are happy with the settings.

[mrscorpio]

Hi Bigmally,
Sorry I should have explained a bit better. To get the window actually closed at 14 degs, I had to wind the piston all the way down so the thread is only just in the nut. I wondered if the wax may have expanded unevenly as the piston was lying on its side in the box when I bought it. Now its in place it is vertical and I wondered if it may need to warm up / cool down so it levels out correctly.

[Bigmallly]

Hi Bigmally,
Sorry I should have explained a bit better. To get the window actually closed at 14 degs, I had to wind the piston all the way down so the thread is only just in the nut. I wondered if the wax may have expanded unevenly as the piston was lying on its side in the box when I bought it. Now its in place it is vertical and I wondered if it may need to warm up / cool down so it levels out correctly.

Yes, you could be right. I had the opposite experience in that the greenhouse hit 18 degrees & the vent was still closed so I wound the piston untill the vent started to open. It's been fine ever since.

[piskieinboots]

I'm pretty sure mine opens around 23

[Patchninja]

I fitted an auto window opener the other day. I followed the instructions - winding the piston so half the thread was showing either side of the nut. The problem with this was the window was now open at 14degs. Do you have to let the piston ( wax filling ) settle for a few days as the temp goes up and down ? I would assume it came out of the box warm and was lying on its side.

Before I fitted a new one this spring, I had to put it in the fridge first!
It's working just fine now.