Chicago suburb, Lake County, and PEX is allowed here. We follow the Illinois Plumbing Code, with a few local amendments that aren't applicable to this issue.

The local Plumbing Inspector says that air chambers are required at every fixture, even though the manufacturer says that air chambers are not needed with PEX.

So instead of nice, continuous home runs with just a connection at each end, we now have some 90's, T's, plugs, and many more connections per fixture. I think this really blows and negates several of the advantages of using PEX:minimal # of fittings, fewer joints (possible weak/leak points) and directional change with less pressure loss than 90degree fittings.

Can someone shed some light here and let me know the reasoning behind this? Why would a plumbing inspector require air chambers with PEX when the mfgr says the opposite? Or is it that they are just so used to copper that they want PEX systems to be run like copper, except they'll let you use plastic. Yeah I did ask, but didn't get anywhere.