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  1. gopack85

    Chiller Optimization

    Thanks for the input. Right now the chiller temp SP is 40F as due to incorrectly sized coils in one of the critical rooms, any temp higher than 42F to those coils will set off humidity alarms. I do have them on a LON network with percent load. It's critical that a chiller stage up if the...
  2. gopack85

    Chiller Optimization

    I'm having some issues with my chillers short cycling. We have four chillers with fixed flow primary pumps, variable flow secondary pumps, and an open bypass. When the secondary flow requirement increases beyond the primary pumps another chiller is staged on since we get reverse flow through the...
  3. gopack85

    Chiller Secondary Loop VFD Control

    Thanks for the tips. My first thought was to try and change to a variable primary system but I'd have to show that the cost of retrofitting an existing system would be less than the overall savings. Right now I'm trying to do some "free" control modifications to optimize the current set up a...
  4. gopack85

    Chiller Secondary Loop VFD Control

    So you are actually controlling pump speed directly directly valve position once they start opening?
  5. gopack85

    Chiller Secondary Loop VFD Control

    I think I understand the method. What have you seen as a successfull reset method time? As in, how often do you look at the valve % and how much do you adjust the dp set point?
  6. gopack85

    Chiller Secondary Loop VFD Control

    Wouldn't the lag carry over into the dp reset since its still based on valve %?
  7. gopack85

    Chiller Secondary Loop VFD Control

    I have a secondary loop VFD controlled with 10+ 2-way modulating valves and two 3 way valves. The VFD control is currently set to maintain a specific dp. In the winter time, the flow that this loop maintains is beyond what one chiller with a constant flow pump can provide (actual load in tons is...
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