[Equest-users] Question regarding DX-Cool-EIR-fPLR & IEER

Kathryn Kerns kathryn.kerns at bceengineers.com
Thu Oct 3 10:50:02 PDT 2013


Thanks for the input. Yes I know we need to pull out the fan energy and yes I am familair with the AHRI 340/360-2007 methodology for creating an IEER value, and yes I concede that modifying the part load curve without modyfing the other curve is going to be an approximation. The point is - given a baseline IEER value can we create a baseline part load DX curve without the raw data? For that matter, given a proposed system IEER can we create a part load curve? I think the answer is, you can't. I can probably solve the proposed part load problem by asking a manufacturer for their IEER data, but what to do about the baseline?
 
I sense there is a way to gain energy savings here, but I am not sure how to go about proving it to the satisfaction of our unfortunately challenged LEED reviewers.

________________________________

From: Paul Riemer [mailto:Paul.Riemer at dunhameng.com]
Sent: Thu 10/3/2013 8:20 AM
To: 'Bishop, Bill'; Bobby Almeida; Kathryn Kerns; equest-users at lists.onebuilding.org
Subject: RE: Question regarding DX-Cool-EIR-fPLR & IEER



Remember a packaged cooling equipment EER is the ratio of cooling effect (Btu/hr) provided divided by the total (supply fan, compressor, condenser fans and controls) energy draw (W).

So to get from the packaged unit EER to DOE-2 cooling EIR value and the EIR curves you need to remove the fan energy at each point.  That AHRI standard that Bill mentioned addresses what the fan volume and static pressure (but not explicitly fan power) has to be at each of the four part load points.  Good luck.  

 

Paul Riemer, PE, LEED AP BD+C 

DUNHAM

 

From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Bishop, Bill
Sent: Thursday, October 03, 2013 8:58 AM
To: Bobby Almeida; Kathryn Kerns; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Question regarding DX-Cool-EIR-fPLR & IEER

 

You would need to evaluate/modify two separate curves to match the IEER. IEER is a function of part load and condenser temperature, holding return air temperature (EAT) constant. The COOL-EIR-FPLR curve is a function of the part load ratio only, not temperature. The COOL-EIR-FT curve is a function of EAT and condenser temperature (OAT or EWT).

 

The IEER formula and methodology are described in section 6.2 of AHRI 340/360-2007 with Addenda 1 and 2 <http://www.ahrinet.org/App_Content/ahri/files/standards%20pdfs/ANSI%20standards%20pdfs/ANSI%20AHRI%20Standard%20340-360-2007%20with%20Addenda%201%20and%202.pdf> .

 

Regards,

Bill

 

William Bishop, PE, BEMP, BEAP, LEED AP | Pathfinder Engineers & Architects LLP

Senior Energy Engineer

 

134 South Fitzhugh Street                 Rochester, NY 14608

T: (585) 325-6004 Ext. 114            F: (585) 325-6005

bbishop at pathfinder-ea.com <mailto:wbishop at pathfinder-ea.com>            www.pathfinder-ea.com <http://www.pathfinder-ea.com/> 

P   Sustainability - the forest AND the trees. P   

 

From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Bobby Almeida
Sent: Wednesday, October 02, 2013 8:42 PM
To: Kathryn Kerns; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Question regarding DX-Cool-EIR-fPLR

 

Hi Kathryn,

 

On our projects where we take credit for part load efficiencies we use addendum s to 90.1-2007. This adds in IEER values for units so you're comparing apples to apples. The only projects we have modeled this on have had baseline systems that were 9.5 EER with an IEER of 9.6. With such a small difference between EER and IEER, the 25%, 50% and 75% values aren't that important. 9.5 EER at full load and 9.6 at the other values will get you the 9.6 required for baseline. For information on how to make curves I would look through the archives of this user group, there have been some great explanations.

 

Bobby Almeida, E.I.T.    

Project Engineer

 

 

4051 Glencoe Ave. Suite 5 

Marina del Rey, CA 90292

p. 310.591.8172

c. 925.980.2025

www.gaiadevelopment.com <http://www.gaiadevelopment.com/> 

 

P Please consider the trees before printing this email

 

Legal Notice: This message and any materials attached are confidential, and are intended solely for the use of the addressee. If you are not the intended recipient, be advised that unauthorized use, disclosure, copying, or distribution is strictly prohibited. If you received this message in error please do not read it, notify the sender, and delete your copy immediately. 

 

From: equest-users-bounces at lists.onebuilding.org [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Kathryn Kerns
Sent: Wednesday, October 02, 2013 3:37 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Question regarding DX-Cool-EIR-fPLR

 

Everyone, has anyone ever modified the standard DX-Cool-EIR-fPLR curve to fit a particular DX cooling system? If so, when you compared it to a baseline DX cooling system, did you use the original eQuest DX-Cool-EIR-fPLR? 

 

I looked through ASHRAE 90.1 -2007 and although there is full load EER data for air conditioners and heat pumps, there is no IEER data. 

 

However, it occurs to me that if ASHRAE 90.1 starts including IEER data (which shows up in ASHRAE 90.1 -2010 Section 6) how are we going to modify the eQuest DX-Cool-EIR-fPLR to accommodate the IEER? The IEER is a single number and we have no idea what the 25%, 50%, 75% cooling load ratios look like.

 

Hmmm.

 

 

Kathryn Kerns

Systems Specialist

BCE Engineers, Inc.

| Ph: 253.922.0446 | Fx: 253.922.0896 | 

 

 

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