My New Greenhouse :)

That is not a solar powered fan - I have a couple of those that sit on heaters to make sure the heat gets distributed without using electricity of any form.

This type of fan can be hooked up to a solar panel:

https://www.amazon.com/Portable-Cei...851455&sprefix=12v+overhead+fan,aps,97&sr=8-2

or

https://www.amazon.co.uk/EVGATSAUTO-Adjustable-Electric-Universal-Vehicle/dp/B08CKY6QRG/ref=sr_1_2?crid=32M7H7LED3K2U&keywords=12v+overhead+fan&qid=1672851381&sprefix=12v+overhead+fan,aps,149&sr=8-2

 

Had chance today to check the new strip of polycabonate re the condensation and found that the bottom breather strip had come unstuck leaving the ends fully exposed so expect that wll have allowed the colder air to get in and so loosing its thermal insulation properties.

Being a showery day not dry enough to properly reseal the end of the sheet but did put some temporary tape on it, be interesting to see if that lowers the condensation.

@Michael Hewett , did your builder fit such closure and breather tapes to your twinwall roofing sheets ?

 

I looked at the reviews in Nigel's link and iot didn't appear to be worth the money.
And personally I dont think a fan would have much effect on that amount of moisture, they are good at keeping the air moving perhaps to stop mould but they will just be moving around the same damp air.
Through ventilation on dry windy days is always good.

 

I still think all that amount of condensation is due to the fact we had a lot of rain before the windows were put in, and the walls and floor were very wet. After I get rid of it and the walls dry out I don't think there will be so much condensation forming.

Yes @ricky101 they did.