Need some help with vent clearance for a Harman P38. I’m looking to install this through my outside wall but was bummed when reading through the manual and found you need minimum 48” from opening window. This is just not going to happen in my common rooms. My only other option, I had thought at the time was to go up from the middle of the house through the roof adding allot of money to the installation. During my visit to the local Harman dealer I was thrown a curveball. “If you add an outside air kit the minimum clearance is 18 inches.” Well I couldn’t find it in the P38 manual but I do see a reference to that in other manuals by Harman. I stopped by the local code enforcement guys and they let me know that when they inspect the installation, they go by the manufacturer’s recommendation. Does anyone know why some models have the reference and some don’t?