Booster fan control
Hello to all,
I have a question regarding a booster fan control set up. I installed a booster fan for a bathroom exhaust duct circuit that is about 60 feet long (6" hard pipe) including elbows. The booster fan is about 5 feet before it exits the building.
I thought I could use a "Cleveland Control" pressure sensing switch to turn on the booster fan (sensing pressure on the suction side of the booster fan). The problems is that not matter what I set the pressure switch at to kick on the booster fan, the fan is being turned on and then off because the booster fan is causing the pressure (in the exhaust pipe) to decrease fairly quick at the spot I have have my 1/4" hose connected into the hard pipe. I took pressure reading (with a manometer) further along the exhaust pipe to see if I can find a better spot, but the pressure decreases (goes from .10 water column to -5 water column causes booster fan to go off) even 20 feet away for the booster fan.
I am thinking I might need some type of relay timer that would keep the fan running once it first starts for at least five minutes at a time.
Funny thing is that most booster fans look like they come with the pressure switch mounted right at the booster fan.
Hopefully someone's has some idea's about this issue.