Quote:
If we had month after month of 45degree heat then I'd be more worried. As it is I reckon the fan would only be running for a few days a year.

(And, to be clear, I agree that the loft is one of the *last* places I'd suggest for server location (probably better than the bathroom though))

...and to be equally clear myself I'm not talking about 45 degree outside I am talking about the heat that the inside of the loft reaches in direct sun.

In my monitoring back in 2005 or whenever it was the temperature in my loft exceeded 45C for hours every day for weeks at a time. It didn't need to be hugely hot outside, just as long as you got a few hours of uninterrupted summer sun.

My garage roof has very similar construction to our house roof, but it isn't in direct sun, so when the loft is at >45C the garage can be <25C. So it obviously does depend a lot on the specific circumstances.