englander in basement oak question

[smitty273]

Was wondering if anyone could tell me why you need a larger outside air pipe if the install is in the basement. Englander says to use a 3 inch pipe if it's a basement installation.

thanks.

 

[SmokeyTheBear]

I suspect it is because of the additional air flow restriction caused by the multiple bends in the intake pipe the additional cross section would reduce the impacts of the bends. This is similar to using 4" exhaust pipe if the EVL exceeds a certain figure or your altitude puts you somewhere in the mountains.

 

[imacman]

.....the additional air flow restriction caused by the multiple bends in the intake pipe.....

Correct Smokey, in addition to the extra length that the OAK has to be in a basement install.

 

[smitty273]

thanks for the replies. knew there had to be a simple reason for it.