radiator control valves on monoflo tee system?

R. B. (Buzz) Estes

Relatively new customer has a 80+ year old hot water system. He thinks we are great because we corrected some piping others had done years ago, later attempts to correct it made it worse and we simply piped a few radiators on monoflo tees correctly and now they work!! But now they want better temp. control and lower utility bills in the 8000=sq. foot house. If we install a thermostatic control valve on each radiator will we totally screw up the total flow because of extra resistance when all of the flow must go through the tees due to the vavles being closed. They want to be able to close off, or at least lower the temp., in unused rooms. Soon to be only two people is the big house.