5.8.3 - Cooling Tower curves

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What NACM Section(s) are relevant to this issue?
5.8.3 Cooling Towers
  Cooling Tower Capacity Adjustment Curve(s)

Explanation of issue:
1) There is only one set of cooling tower capacity curves.  Is this supposed to 
cover open towers and fluid coolers?

Proposed resolution:
Review and confirm

Please provide any additional information below.

Original issue reported on code.google.com by da...@360-analytics.com on 10 May 2013 at 9:11

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Also:
5.8.3 Cooling Towers
  Cooling Tower Power Adjustment Curve

The descriptor indicates that the independent variable of the TWR_FAN_FPLR 
curve is the capacity PLR, fan flow or fan speed ratio. 
DOE-2.1 documentation indicates fan power ratio is a function of airflow ratio
DOE-2.2 documentation indicates fan power ratio is a function of fan speed 
ratio (I believe that for open towers, static is low so fan speed and fan flow 
should be closely related to eachother, so presume OK to use speed/flow 
interchangeably).
E+ documentation indicates fan power ratio is a function of airflow ratio

The ACM curve definition and variables does not appear to be consistent with 
any of the tools. 

Resolution:
Revise ACM equation and description input variables to match DOE-2/E+ 
convention.

Original comment by da...@360-analytics.com on 10 May 2013 at 9:49

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Fluid cooler: recommend tabling this configuration for now, since I don't think 
it's very common in California.

For the PLR definition: I took this from the ECB compliance supplement, but I 
think it should be the ratio of airflow (cfm) to design airflow (cfm) for this 
curve. I will update the ACM to reflect that.

Original comment by JohnJArent on 21 Nov 2013 at 12:21

• Changed state: Discussion

[GoogleCodeExporter]

Fluid coolers are pretty common for WSHP systems, at least up here in the 
Pacific NW.  Roger is implementing the rules for this, so leaving this up to 
him to finalize in rules.

Original comment by da...@360-analytics.com on 25 Nov 2013 at 11:45

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I don't have a feel for how common fluid coolers are.  Do we have a source for 
an appropriate performance curve for fluid coolers?

Original comment by rhedr...@archenergy.com on 25 Nov 2013 at 11:53

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I don't see any place in the EnergyPlus documentation that specifies a 
performance curve for fluid coolers. There are different inputs also, such as 
the UA value, that we don't have in the ACM.  I don't think we can simply 
specify a performance curve for these types of systems, and I believe that some 
level of testing would be required to verify that they are supported by 
EnergyPlus8/OpenStudio.

The resolution is to not support fluid coolers with this release.

I will add clarifying language to the performance curve section of the cooling 
towers to indicate that the parameters only apply to open cooling towers.

Original comment by JohnJArent on 4 Dec 2013 at 10:15

• Changed state: WontFix

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Kyle reports that E+ includes a fluid cooler object.  AEC will investigate. 

Original comment by rhedr...@archenergy.com on 6 Dec 2013 at 11:29

• Changed state: Discussion

[GoogleCodeExporter]

This is not in the ACM scope, although it appears to be supported by EnergyPlus 
(don't know about OpenStudio).

The model for fluid coolers doesn't require a performance curve and requires 
additional inputs not in the ACM.  Also, I don't believe that closed circuit 
towers can be modeled with the existing cooling tower performance curves.

Original comment by JohnJArent on 18 Dec 2013 at 10:31

• Changed state: WontFix