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Convert SEER to EER for eQUEST

asked 2014-12-09 10:33:04 -0500

jng gravatar image

updated 2015-11-10 15:20:23 -0500

I am sure this question has been asked many times before in the onebuilding list but I wanted to have it answered here as well. When ASHRAE 90.1 or MNECB/CNEB ask for a performance rating for a cooling system in SEER, how does one convert this SEER value into an EER to be used in eQUEST?

I know equest uses some formula of conversion in the wizards however where does this formula come from? is it really applicable? I am interested in hearing some thoughts on this subject.



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answered 2015-03-06 12:30:53 -0500

Erik Kolderup gravatar image

Just noticed a 2013 paper from Texas A&M, METHODOLOGY FOR CALCULATING COOLING AND HEATING ENERGY-INPUT-RATIO (EIR) FROM THE RATED SEASONAL PERFORMANCE EFFICIENCY (SEER OR HSPF). That paper presents correlations to give you COP as a function of SEER. They report this correlation works better than earlier methods from FSEC and ASHRAE RP-1197.

Find it here:

The paper is marked DRAFT. Perhaps one of the authors can report on status.


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These formulae are published in ASHRAE 90.1-2013, G3.1.2.1.

keb gravatar image keb  ( 2016-02-09 15:39:43 -0500 )edit

answered 2014-12-09 11:05:49 -0500

updated 2014-12-09 11:47:07 -0500

keb gravatar image

Two formulas that I've used in the past:

EER approximately equal to 0.9 * SEER
EER = -0.02SEER^2 + 1.12SEER

The first is just from general googling, and was a rough consensus value between several sources. The second is from the eQuest mailing list forums. Using a SEER of 10 gives you 9 from the first, and 9.2 from the second.

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I believe the second equation can be found in TRANE hvac equipment literature. It is the one we typically use.

JO gravatar image JO  ( 2014-12-09 11:39:40 -0500 )edit

answered 2014-12-09 20:30:06 -0500

yongqingzhao gravatar image

updated 2014-12-09 20:34:26 -0500

EIR is used in eQUEST,all the EER/SEER/HSPF will be converted to EIR finally.

image description

CAP Total Cooling Capacity(Btu/h)
EER ARI Rated Energy Efficenice Ratio

image description
Cooling EIR=(1/EER-0.012167)/((1/3.413)+0.012167)
the constant 0.012167=(365/1000)(400/12000)

Heating EIR = (1/(COP3.413)-0.012167)/((1/3.413)-0.012167)
Heating EIR = (1/((HSPF

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Asked: 2014-12-09 10:33:04 -0500

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Last updated: Mar 06 '15