Impact of Cooling Tower EEM on Space Cooling load

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Hello everyone!
I have modeled water cooled packaged DX systems that are connected to a
cooling tower having a single-speed fan and pump. When I change the
single-speed fan and pump with variable speed drives as an EEM, the results
show a reduction in "Pumps & Aux." load as well as "Space Cooling" load. In
fact, sometimes the reduction in space cooling load seems to be greater
than "Pumps & Aux." load itself. Can anybody decipher what is the relation
of VSDs pump and fan of cooling tower with space cooling load?


Dilshad Ahmed Khan's picture
Joined: 2018-03-05
Reputation: 0

When you say loads, do you mean the end-use energy breakdown totals? (Loads = heat/cooling gains in the spaces ? VFDs should not be affecting heating or cooling loads.)

If the change to the tower fan motors allows a different control of the condenser water temperature to be colder water then the compressor energy of the individual heat pumps would go down.


David S. Eldridge, Jr., P.E., BEMP, BEAP, HBDP, GGA

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David Eldridge's picture
Joined: 2012-05-08
Reputation: 1