We have just rturned from Cornwall after a nice week by the sea, earlier this year we had Van Bitz fit a dometic air conditioner to the hab section, well last week it got tested to the max 27 degrees in the shade and 20 dedrees in the Hab, perfect not cheap but so good, noise etc were fine and SHMBO had air con, hairdryer and kettle on at one point , but still didnt manage to trip anything. if anyone is thinking of it its probably one of the better things to fit.
have fun
have fun