We have two (2) 1,000 TR Carrier 19xr, centrifugal, R-134a chillers, and has been around for 15 years.

I want to upgrade it with VFDs to reduce our energy consumption. For 6 hours a day, the chillers is running at 75% load. You shut down one chiller, then phone starts ringging.

What VFDs and controls would be recommended for the chiller upgrade. We are open to use parts from other brand/manufacturer.

And lastly, is it feasible just to retrofit it with multiple turbocors?