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5.7.6.5 - Heat pump EIR_fTemp equations #222

Closed GoogleCodeExporter closed 9 years ago

GoogleCodeExporter commented 9 years ago
What NACM Section(s) are relevant to this issue?
5.7.6.5 Heating Systems
  Electric Heat Pump Heating Efficiency Adjustment Curve(s)

Explanation of issue:

For Air-Source HPs, the independent variable of the EIR_FT is listed as the 
ratio of Todb/Tdb (entering coil).  However, using the AHRI-340 HP standard 
rating conditions (47F odb, 70F db) and the curve that is listed in the ACM, 
this curve output does not equal 1 at the rating point.  Using Todb as the only 
independent, it does equal 1.  Finally, E+ literature indicates that if the 
curve is a function of one variable only, the independent is Todb.

Proposed resolution:
Review and confirm that equation is function of Todb only.

Please provide any additional information below.

Original issue reported on code.google.com by da...@360-analytics.com on 10 May 2013 at 11:52

GoogleCodeExporter commented 9 years ago
I discovered this same issue: DOE-2.1e documentation lists the variable as 
Todb/Tdb, but at the rating condition the output equals one when the 
independent variable of Todb=47 is used.

I will look into this one further but I'm pretty sure your interpretation is 
correct.

Original comment by JohnJArent on 22 May 2013 at 12:06

GoogleCodeExporter commented 9 years ago
Reviewed with John, he will make update in ACM.  No need to post the revised 
language here, will make this assumption in rules.

Original comment by da...@360-analytics.com on 7 Nov 2013 at 6:35

GoogleCodeExporter commented 9 years ago
Made changes to upcoming (Version 3) release.

No changes are required to Appendix 5.7 (Perf Curves) to address this issue.

Original comment by JohnJArent on 11 Nov 2013 at 10:28

GoogleCodeExporter commented 9 years ago
Closing, reviewed and confirmed changes in language posted in issue 232.

Original comment by da...@360-analytics.com on 25 Nov 2013 at 11:48