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Impact of altitude on chiller plant performance

asked 2015-03-17 09:36:47 -0600

301_Hours gravatar image

updated 2015-07-10 13:44:21 -0600


I'm starting a new model in Colorado with an elevation of 5,000 ft that has an air-cooled chiller plant. When running selections to determine the performance of the chiller I'm noticing that the performance of the chiller is worse due to the density of the air, which makes sense as more fan power is needed to reject the heat.

When I run a chiller only eQUEST model and change the elevation from 0 to 5,000ft, there is no change so I don't believe eQUEST accounts for air density at the plant level like it does on the system level.

So my question is, how do I derate my baseline DX system performance to account for the altitude difference? If I plug in 90.1 values into the baseline and actual selection values, I'm unfairly improving the baseline. I believe AHRI tests everything at sea level.


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I'm also interested in this. Can you share how you dealt with this? Did Jeremy's suggestion below work or did you do something else?

anchapin gravatar image anchapin  ( 2018-02-26 06:53:54 -0600 )edit

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answered 2015-03-21 10:23:59 -0600

updated 2015-03-21 10:27:57 -0600

I'm not quite sure if that would work but what I would try to do is, update the air properties and atmospheric pressures of the weather file you are using to reflect the change in altitude.

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Asked: 2015-03-17 09:36:47 -0600

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Last updated: Mar 21 '15