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Hi, I have a question? I can install a VFD on the blower of the roof top package Unit? If yes what do i do with the refrigerant? it will ice up the coil write?
I heart that i can fix this installing a solenoid valves on the refrigerant lines and bypass the evaporator. This is thrue?
What is it that you are trying to acheive by fitting the VFD and why ?
the only time i have seen a VFD used on the EVAP-blower is in VAV application, this is to maintain the static pressure in the duct and keep it from overpressurized the duck. as for installing a HOTGAS bypass, what is the point. You will be waisting energy.Quote:
Originally Posted by 8lien
As you VFD ramps down you will have to cycle you compressors to keep the coil from freezing.
Rather have one on the compressor which can maintain a constant suction pressure . It will enhance compressor life & save you energ etc
Packaged unit evaporator fan itself will be 1 to 3 HP depending on the size and VFD for such application is not economical.
Even where VFD are used for compressors it is advantageous only when there is wide variation in wet bulb temperature for water cooled chillers.
No doubt VFD will save energy but Life Cycle cost need to be assessed as Operation cost alone is to the tune of 55 to 65%.Logically for higher size motors say multiple AHU's having VFD will save lot of energy.
Thanks for the fast response if I have another question I will ask you guys. :)