I wasn't going to become a murderer :O I was going to give them to a friend that's all haha, I'll try running 'em so they are on the majority of the time at night man thanks.
Dude if you're in the UK theres no reason to have temp issues. Either your intake air isnt cold, or you're not venting properly. can you move the intake line to underneath a window (cold air falls)...
If you are venting air back into your room your tent temperature will probably mirror the temp of the room so venting it outside was what I was going to suggest also.