Has anyone retrofited a VFD onto an existing 700 ton chiller? We are looking to make our building more energy efficient and the chill water system has the greatest load. Thanks.
I did some cursory research into this during a study for replacing (not rebuilding) a 600-ton chiller. Trane felt that a VFD was overkill because the vanes in the compressor inlet varied the load enough to reduce operating costs. Trane does not offer the VFD option. However, York claimed a very good payback using a VFD (they do offer the option). York's calculated payback was impressive. However, as I remember, the extra cost was significant.
I'm writing this at home. If you're interested, I can look at my notes at work. My work email is jhh@eeiteam.com.