Hello,

I have a gas stove located on an interior wall. Is it a safe practice to run the ducting from the interior wall, down into the basement (4 foot), and turn 90 degrees to duct outside (8 foot)? My thought is to mount the motor/fan in the basement at the exterior wall location.

Do you always have to run ducting in an upward or level plane?

Thanks

Not really. Too much duct and a down shot also not good. It will trap greast. Best is strait up and out since you cannot go directly outside because of an interior wall setup.