Portable AC exhaust pipe length

delgriffith

I have a portable AC that came with about a 5 foot long exhaust pipe and I noticed the instructions said not to extend the exhaust with another pipe. Unfortunately I need a 12 foot pipe.

I wasn't able to find any information to tell me why the exhaust pipe should not be extended, but it seems to be fairly standard across all portables. If I need to insulate the pipe or put an inline booster fan in that would be fine with me, but I just need to know if it will solve problem. Any ideas?

Yoyizit

HVAC websites probably have rules of thumb or nomographs for using a longer but larger diameter pipe that offers the same resistance to airflow as the smaller diameter 5' pipe.