5.7.6.5 - Heat pump EIR_fTemp equations

[GoogleCodeExporter]

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]

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

• Changed state: Resolved

[GoogleCodeExporter]

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]

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

• Changed state: Fixed

[GoogleCodeExporter]

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

• Changed state: DoneVerified