Thanks to all for some excellent feedback. I've turned all of these over to my Controls Tech and he is sorting through so I can give good technical responses to these for clearly describing the situation and hope to have by Monday. This is a retrofit so we had no control over the way it's...
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...
Ok. I am interested in the valve percentage open control, but don't know the concept. How would that control scheme work, and would it require replacing all control valves, or just one? If one, where should it be located?
Thanks to all, by the way. Very helpful input.
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...
