We are installing a shower with a handheld and a fixed showerhead fed by 1/2 inch pipe. Available valve systems are either:
- A single function thermostatic valve, rated at 10.0 gpm, with separate volume controls for the showerhead and handheld. (This valve is a 3/4 inch so would have to use an adaptor from our 1/2 inch pipe.)
- A multifunction valve (1/2 inch), rated at 8.6 gpm, with one setting for showerhead, one for the handheld, and a shared function.
I don't know enough hydraulics or enough about shower valves to be confident of choosing the best system/optimal configuration.
Assuming the user will run both the showerhead and the handheld simultaneously, will the separate volume valves in system 1 provide better water pressure than the shared setting on the multifunction valve (system 2)?
Would the different pipe sizes matter, given that the house piping is 1/2 inch?
Does the type of valve matter (integrated valve versus single-function thermostatic with volume controlled separately)?
Does the difference in gpm between the two valves matter?