Thanks to all those who responded on the door seal and fan.  Lots of good information and ideas to work from. 

It appears that we do have some sort of slow leak and now the challenge is finding it, but we now have some good methods to hopefully track it down quickly.  I will report back what we find. 

We also received a lead on a potentially much quieter fan motor which we will look at.

Regards,

Denis

N750PJ