I should first point out that the system I'm referring to will be a self build DIY project. Fan and Filters being the only items purchased complete, And I'm still in the design phase but I'm not a HVAC expert at all. USA has forced air more commonly than here in the UK so I'm hoping you can help me out.
This is a room air filter, It will go under the stairs where I can hopefully sound proof it.
2 or 3 stage filter setup depending on pressure drop to clean the air for a 45m3 room, intending to get 4 air changes per hour.
Fan I have selected thus far is an ERK 250 which will blow into the filters.
Each filter has an initial Pa drop of lets say 50Pa new with a replacement final pressure drop of say 200Pa. My intention is to design a circuit that will have a differential pressure sensor to measure the pressure before and after the filter to calculate the pressure drop caused by that one filter thereby allowing me to calibrate it to indicate when said filter should be changed. The same for the other filters that follow.
Will the first filter effect the reading for the 2nd filter? I can't think of a reason why it would but then air flow dynamics is a black art to me.
Will it work? Are there any commercial filter change sensors out there and how do they work?