[Bldg-sim] EER to EIR Conversion for LEED Baseline

Bishop, Bill bbishop at PathfinderEngineers.com
Thu Nov 13 11:25:33 PST 2008


Kevin,

 

This is an important question. I am not aware of a definitive answer. I
just looked at 90.1-2004, 90.1-2007 and the User's Manuals for both. I
see no change in 2007 specific to how to determine the equipment
efficiencies.

 

I agree that if you determine efficiency by the baseline equipment size,
you generally end up using better efficiencies for the baseline
equipment. As you mentioned, this is because you are required to model
one system per zone. At the same time, when you determine fan power
based on the baseline equipment size, you use higher kW/cfm. I am
finding that, because of this, my models rarely show cooling energy
savings, and usually show huge amounts of heating energy savings.
(Baseline furnaces are 80% efficient and my proposed systems approach
95%. Also, the buildings I model are mostly in NY - high heating hours.
I often have heat recovery systems, which also help with the heating but
not much with cooling.)

 

So, for know, it makes sense to me to determine the baseline
efficiencies and fan energies from the oversized (10%/25%) baseline
capacities. Knowing this, I have to avoid the tendency to model every
single space on the architectural drawings, and try bundling them better
into zones. (Make all the spaces served by one VAV box a single zone.
Make all the spaces served by a single-zone system one large zone,
unless the uses and orientations differ greatly. Etc.)

 

That's my $0.02.

 

William Bishop, EIT, LEED(r) AP | Pathfinder Engineers LLP

Mechanical Engineer

 

3300 Monroe Ave., Suite 306 
Rochester, NY  14618

TEL (585) 218-0730 Ext. 114
FAX (585) 218-0737 

bbishop at pathfinderengineers.com

 

www.pathfinderengineers.com

P Please consider the environment before printing this email

________________________________

From: Kevin Kyte [mailto:kkyte at robsonwoese.com] 
Sent: Thursday, November 13, 2008 1:49 PM
To: Bishop, Bill
Cc: Aulbach, John
Subject: RE: [Bldg-sim] EER to EIR Conversion for LEED Baseline

 

My apologies but I must bring this up again, I get too easily confused.
My questions pertain specifically for getting EIR baseline for budget
system 3 or any budget system with Packaged Single Zones.

 

I am unclear on what capacity to use to get baseline efficiencies.
Generally, the proposed capacity of an air-side system will serve
multiply thermal zones but the baseline requires systems for each
thermal zone.  This creates base system capacities much lower depending
on zoning and appears that it may unfairly penalize depending on how the
zoning is done.  If a proposed system capacity is between 240,000 and
760,000 then would all baseline systems require a 9.3 EER or because all
single packaged zones have a baseline capacity of less than 65,000,
should baseline single packaged systems be 12.0 EER?

 

Secondly, it would appear more timely to generate baseline kW/CFM and
EIR based on proposed parameters and then input these numbers to each
packaged single zone corresponding to its proposed air-side system.
Although more favorable numbers may be obtained using baseline
parameters.  So if I am Calc'ing individual packaged single zone EIRs
and I cannot subtract the fan power found using proposed air-side system
CFM numbers but CFM numbers found from the baseline modeling reports and
also capacities found from autosized baseline modeling reports.  Any
thoughts?  Thanks.

 

Kevin

 

From: Bishop, Bill [mailto:bbishop at PathfinderEngineers.com] 
Sent: Thursday, November 06, 2008 4:52 PM
To: Kevin Kyte
Cc: Aulbach, John
Subject: RE: [Bldg-sim] EER to EIR Conversion for LEED Baseline

 

Kevin,

 

1.)     What is your reasoning for sizing the baseline that way? Why
wouldn't you just autosize the baseline and increase by 15%/25%?

2.)     In eQUEST, what is the difference between these two methods:

a.       Specifying 1.15 and 1.25 for the cooling and heating capacity
ratios, respectively, without entering any numbers for capacities, and
using the resulting energy consumption

b.       Going back and manually entering the capacities that the
program reports and running the program again

3.)     For the EIR, I determine what efficiency to use based on the
oversized baseline capacity, but I could be convinced to size it on the
1.00 autosized capacity instead.

 

Bill

 

William Bishop, EIT, LEED(r) AP | Pathfinder Engineers LLP

Mechanical Engineer

 

3300 Monroe Ave., Suite 306 
Rochester, NY  14618

TEL (585) 218-0730 Ext. 114
FAX (585) 218-0737 

bbishop at pathfinderengineers.com

 

www.pathfinderengineers.com

P Please consider the environment before printing this email

________________________________

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Kevin Kyte
Sent: Thursday, November 06, 2008 4:28 PM
To: Aulbach, John; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] EER to EIR Conversion for LEED Baseline

 

And the baseline EIR should include the wattage calc'd from G.3.1.2.9?

 

Backing up for a moment, there is a funny way to determine the
oversizing capacities, especially for PSZs.  Here goes:

 

Run the design model with design capacity, run the design model
autosized, find the ratio.

Run the baseline model autosized, apply the ratio.  Now oversize for 15%
cooling and 25% for heating.

 

Does anybody do this differently, because the fine print doesn't exactly
say that much. 

 

 

 

From: Aulbach, John [mailto:jaulbach at nexant.com] 
Sent: Thursday, November 06, 2008 4:05 PM
To: Kevin Kyte; bldg-sim at lists.onebuilding.org
Subject: RE: [Bldg-sim] EER to EIR Conversion for LEED Baseline

 

Kevin:

 

I believe it is 15% oversize for cooling and 25% for heating (Page 176 -
Appendix G - ASHRAE-90.1-2004 - I don't have 2007 yet). This is aside
from fan calculations.

 

This would apply to either package units or central plant equipment,
whichever is specified as baseline.

 

John R. Aulbach, PE, CEM

Project Manager

Nexant, Inc.

701 West Kimberly Ave., Suite 245

Placentia, CA 92870-6342 USA

Phone: 714-524-4402

Fax: 714-524-4407

email: jaulbach at nexant.com

 

 

________________________________

From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Kevin Kyte
Sent: Thursday, November 06, 2008 12:54 PM
To: bldg-sim at lists.onebuilding.org
Subject: [Bldg-sim] EER to EIR Conversion for LEED Baseline

All,

 

When you Calc your EIRs for baseline, do you use design capacities or
oversized baseline capacities?

 

Thank you. 

 

Kevin

 

________________________________

"This message is for the designated recipient only and may contain
privileged, proprietary, or otherwise private information. If you are
not the intended recipient, you are hereby notified that any disclosure,
copying, distribution, or the taking of any action in reliance on the
contents of this information is strictly prohibited. If you have
received this transmission in error, please notify the sender
immediately by e-mail and delete the original message."

________________________________________________________________________
This Email has been scanned for all viruses by PAETEC Email Scanning
Services, utilizing MessageLabs proprietary SkyScan infrastructure. For
more information on a proactive anti-virus service working around the
clock, around the globe, visit http://www.paetec.com.
________________________________________________________________________

 

________________________________

"This message is for the designated recipient only and may contain
privileged, proprietary, or otherwise private information. If you are
not the intended recipient, you are hereby notified that any disclosure,
copying, distribution, or the taking of any action in reliance on the
contents of this information is strictly prohibited. If you have
received this transmission in error, please notify the sender
immediately by e-mail and delete the original message."


________________________________________________________________________
This Email has been scanned for all viruses by PAETEC Email Scanning
Services, utilizing MessageLabs proprietary SkyScan infrastructure. For
more information on a proactive anti-virus service working around the
clock, around the globe, visit http://www.paetec.com.
________________________________________________________________________

 

________________________________

"This message is for the designated recipient only and may contain
privileged, proprietary, or otherwise private information. If you are
not the intended recipient, you are hereby notified that any disclosure,
copying, distribution, or the taking of any action in reliance on the
contents of this information is strictly prohibited. If you have
received this transmission in error, please notify the sender
immediately by e-mail and delete the original message."

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20081113/c3c88c3c/attachment-0001.htm>


More information about the Bldg-sim mailing list