Just doing a quote for a beauty school and discovered that it is recommend that you put thermostatic mixing valves on shampoo basins. They are also putting in a shower with jets and spa and also a basin, do these also need the valves or can a tempering valve be used for all of the above?
Tempering valves maintain a specific water temperature coming from the water heater source, but, do not prevent fluctuations at the fixture. That is why thermostatic and/or pressure balancing valves are required.
You need a licensed plumber who knows the right valves to install on each one of the fixtures and the correct backflow preventers that are required by the plumbing code.