why more heating usage with evaporative cooler

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Hi,

I'm new to eQuest, recently I'm modeling a office building with evaporative
cooler, I did a sample test and found out that, for the same building,
significantly more heating is consumed with the model using evaporative
cooler than others using DX coil or chilled water cooler. Does anybody
noticed that and, why is that?

Great thanks!

Yitian

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Yitian,

Is the evaporative cooler also controlling the humidity during the heating season? If so, that might explain it. More heating would be needed to compensate for the cooling effect of adding cold moisture to the airstream.

________________________________
Keith Swartz, P.E., LEED AP

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Keith,

Thank you very much for replying this.

I've actually did some investigate into this issue and had some ideas about
possible solutions and, I thought it could because that Evaporative Cooler
runs even during heating season, but since I have the same setting of
cooling & fan schedule for DX Coil or Chilled Water Cooling, why would EVP
Cooler have this problem? And which input represents the humidity control
of EVP Cooler? I wonder which input could determine the set point between
cooling and heating season? Or, I should basically create separated seasons
for the cooling,heating & fan schedule? I guess it would be unreliable.

Thank you Again for your help!

Best,

Yitian

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Yitian,

The humidity control in eQUEST is in the "Basics" tab for the air system in the detailed edit mode. Unfortunately humidity control is not available for an evaporative cooling system. See the lower right corner in the image below.

[cid:image003.jpg at 01CCCEE5.7CA43270]

You can get a sense for space humidity levels from report SS-N to see if humidity control may be an issue. If you find it is an issue, you may need to edit the .inp file. Search the DOE-2 help for keywords like MAX-HUMIDITY and MIN-HUMIDITY for more details. The increased heating might be caused by something else besides humidity control. That's just the first thing that came to my mind.
________________________________
Keith Swartz, P.E., LEED AP

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