We replaced across the line hydronic pump starters with VFD's. The pumps are on the 6th floor of a 6 story office building, pumps down the riser with a return running to the basement and a reverse return runs back to the pump inlet on 6th. We installed a DP sensor at 2nd floor ceiling (2/3...
For energy savings, a vfd is replacing the constant speed motor controller for the building hot water pump. Usually, dp switches are installed at the pump output and 2/3rds out into the system. In this case, the line is in a pipe chase that will not allow DP installation on the piping anywhere...
