Plate & Frame install w/out VFD on Cooling tower and freezing

[wst01]

I am involved in the install and operation of a P&F utilizing a closed circuit cooling tower.My supervisor is convinced we do not need a VFD on the cooling tower for winter operation.
Since this is located in Colorado I am concerned that operating the plate and frame during cold ( below 32 deg F)weather will not be possible.
As we do not have the ability to reverse the fans, will I have continual problems with freezing the louvers in the cooling tower making the P&F operation not an option? My supervisor also decided not to involve an engineer in the design and install of the P&F.
We have 19% glycol in the system,and this system cools a data center. Thanks for you help.

 

[DrRTU]

19% by volume sounds low for your area. I think you should be about 45 to 50%. If you have a fluid cooler by-pass valve, then you would not need a VFD on the fan. Why the P&F in the first place, most free cooling data units are designed for glycol. Liebert has a few good sizing documents. The Liebert fluid coolers have multiple prop. fans all staged on LWT.

 

[wst01]

The main reason for the P& F addition is that we have two carrier model # 19XRV3032351CLH64 400 ton chillers that currently operate 24/7,primarily for the data center in the winter and I have two roof top units with a chilled water coils that use the chilled water in the summer and economizer mode in the winter,with the chilled water loop operating at above 55 deg F to the RTU's.I am located in Denver,Colorado.The Lieberts in the data center are cooled with the chilled water loop. I only have one chiller running at any time and in the winter it operates at about 25%.