VFD 10 tons and above?

Paul S_3

Or anything over 10 tons....i have this big job to quote...its the replacement of 11 package units all ranging from 7.5 to 25 tons....i remember my rep at Carrier told me that NYC adopted an ASHRAE requirement that a VFD is required on package units above 10 ton....while im waiting for my rep to call back i would like to know if any of you guys have experience with this and any info that can help...thanks Paul S

zepfan

I don't know about the code requirements in NYC, but it has been my experience that the installation of a VFD is application specific. If these are constant volume units then installing a VFD would be an initial cost of front, and a maintenace concern in the future. If the units need to produce the same cfm any time they are running, and the units are strictly for comfort cooling, non precision, then you do not need a VFD. You could be a soft start on the motor.
That would cost less up front,require less maintenance in the future, and would easily work with the existing controls in the rtu's. Hope this helps,take care.