Auto vent over winter

I know ventilation is important so is it best to leave the barrel on a auto vent on or off over winter?

 

I've never bothered removing mine, they been in for 4 years and still work fine

 

I fitted mine mid 80's to cedarwood roof vents, never messed around with them. They are still working fine. Probably a good idea to check them on a winters night as the night temperature can be most harmful.

 

You live in a mild climate so you may not need to worry. I take all three of mine out after November 1st. We go down to - shut the front door now!

Listen to fellow countrymen

 

I leave them in place, but have been known to remove them during spells of strong winds, I then tie the the things down so the wind cant get inside the greenhouse.

But I think they are mostly fail safe, ie if the cylinder leaks the springs close the vent, and it will just not open in warm weather.
Not good in the summer, but fine in the winter.

 

I unscrew the hexagonal threaded knobs that the pistons push onto, so the roof vents don't open, possibly letting in birds, horizontal rain, etc., in when I'm not checking it every day.