[E-Revonut]

Resident Tin knocker here.....There not called flow limiters! Volume dampers is the proper terminology. Sorry I gotta be a smart ass when I can. There has been some good advice so far. Linc said it best, istall the volume dampers as close to the main plenum as possible, they will make the biggest difference there and create the least amount of noise in the rooms. If the ductwork isn't wrapped with insulation that would also help, both summer and winter. The dampers that are part of the registers are really only to shut off rooms that you don't use, using them to limit the volume of air will create a lot of noise and have less effect getting the air to the other rooms. That is why you want to install them as close to the furnace/heat exchanger as possible.