ASHRAE 90.1-2013 in Section 11.5.2 specifically accounts for packaged unit COP adjustment if the supply air fan is modeled as part of the air loop, as opposed to the HVAC unit itself, as its the case many times. I have not come across something equivalent for 2015 IECC. Does one just use the COP from Tables 6.8.1-1 through 6.8.1-4? Or should one apply the methodology from ASHRAE 90.1-2013 to 2015 IECC?
Due to 2015 IECC referencing ASHRAE 90.1-2013 and 2015 IECC not providing a specific calculation we use the ASHRAE methodology in 2015 IECC code compliance energy models. The COP values from table 6.8.1-1 through 6.8.1-4 should not be used in an energy modeling program that models fan power and cooling power separately!
Thank you kindly for confirming what I had hoped for.
One follow-up question. ASHRAE 90.1-2013 only converts from EER, SEER, COP47 or HSPF to NFCOP. What do you do when your equipment only provides IEER, but not EER or SEER? This is, for example, the case with almost all equipment in Table 6.8.1-1 (as of 1/1/2016). Or does the (before 1/1/2016) vs. (after 1/1/2016) distinction apply only to IEER and thus leave the EER listed in that table in effect regardless of date?
Actually, in regards to my follow-up question, I think the answer is contained in this ICC/AIA Presentation on ASHRAE 90.1-2016. On Page 24, it states "In ASHRAE 90.1-2013 the IEER values were increased with an effective date of 1/1/2016, but the EER levels remained the same".
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