The lower hard drives in the P182 don't get hot if you have the fan in the lower compartment running. I have 2 in there and they run fine.
OK, ta - but I read that some PSUs are larger than standard and needed the fan removing to fir in correctly. Is there any easy way to find out which fits OK? Or, even better, do you know of a good, quiet PSU that will allow me to use the lower fan as well?