[Equest-users] Cooling/Heating Capacity Ratios - LEED Report?

Bishop, Bill bbishop at pathfinder-ea.com
Thu Apr 11 10:41:35 PDT 2013


Nick,

I agree with the others that the LEED reporting should be kept as simple as possible. I also agree with James Hansen that submitting model files sets a bad precedent.

Regarding the autosizing of cooling capacity:
I did two runs on a sample model - one with COOL-SIZING-RATI = 1.0 and one with 1.15, to confirm that the COOLING-CAPACITY shown on SV-A at 1.15 is in fact 115% of the capacity at 1.0 when the COOLING-CAPACITY is not specified.

I believe the reason that the autosized COOLING-CAPACITY as reported on SV-A is not matching the peak cooling load from SS-A (or SS-J) is that the correction factor from the COOL-CAP-FT curve is applied during the sizing routine. The peak cooling load is not likely to coincide with the rating conditions at which the curve is normalized. For instance, the DX-COOL-Cap-fEWB&OAT curve is normalized at 67F Ewb and 95Fdb OAT. The curve accounts for the fact that DX cooling capacity increases when the OAT decreases. If the OAT at peak cooling load is less than 95F, the autosized capacity will be less than the peak load. The COOL-CAP-FT curve causes the hourly cooling capacity to be higher at lower OAT.

Regards,
Bill

William Bishop, PE, BEMP, 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 Nick Caton
Sent: Thursday, April 11, 2013 12:43 PM
To: James Hess; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Cooling/Heating Capacity Ratios - LEED Report?

Thanks fellas!

I've done screengrabs often in the past and am comfortable that will satisfy the reviewer's concerns in this case, it just bugs me that where I'm confident the inputs are correct, the output reports aren't backing me up as expected...

I've also tried summing together space peak loads from the LS reports for a given system (shaky proposition anyway as they occur at different times), and still cannot find the calculated sizing to line up with my input ratios.  I guess this boils down to something I don't understand yet about how the oversizing ratios are applied to arrive at the calculated system capacities...  Further digging in the help files when I get time I suppose.

I don't anticipate having a problem with this review, but if anyone can fill in the gaps that would be much appreciated =)!

~Nick

PS:  I didn't know others are uploading their entire models...  In the reviewer's shoes, I wonder if that makes any combination of specific reports/information look suspect in comparison?

[cid:489575314 at 22072009-0ABB]

NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036
fax 913.345.0617
www.smithboucher.com

From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org> [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of James Hess
Sent: Thursday, April 11, 2013 10:52 AM
To: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: Re: [Equest-users] Cooling/Heating Capacity Ratios - LEED Report?

Same here regarding the screen shots, but I only provide if asked to specifically document something via review comments.  On every submitted project, however, I always upload the eQuest .inp and .pd2 files so that the reviewers can just open the files and look at whatever they need to.  That beats submitting reams of "input reports" which really isn't practical.  I'm assuming the reviewers know eQuest enough such that if they want to verify the Cool Sizing Ratio or Heat Sizing Ratio, they know exactly where to go in eQuest to find the answers, in a matter of seconds.  That seems like a pretty reasonable assumption to me.

Regards,

JAH

James A. Hess, PE, CEM, BEMP
Energy Engineer
TME, Inc.
Little Rock, AR
Mobile: (501) 351-4667

From: equest-users-bounces at lists.onebuilding.org<mailto:equest-users-bounces at lists.onebuilding.org> [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Neil Bulger
Sent: Wednesday, April 10, 2013 6:02 PM
To: Patrick J. O'Leary, Jr.
Cc: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: Re: [Equest-users] Cooling/Heating Capacity Ratios - LEED Report?

I second Patrick, typically I just provide screen grabs of the baseline model and send it off.


Neil Bulger | CEPE | Project Engineer

Integral Group | 427 13th Street | Oakland CA USA 94612
T 510.663.2070 x235

integralgroup.com<http://www.integralgroup.com/> | nbulger at integralgroup.com<mailto:nbulger at integralgroup.com>

 Trust | Nurture | Inspire

Please consider the environment before printing this email.

On Wed, Apr 10, 2013 at 1:19 PM, Patrick J. O'Leary, Jr. <poleary1969 at gmail.com<mailto:poleary1969 at gmail.com>> wrote:
i typically just do screen caps when setting up my baseline model.  it's quick, painless, and makes mothers very happy ... and is done early ...

yeah, one would think there would be a details of hvac systems output report showing the direct inputs, but there's not.  unless you're good at creating custom reports & can create one that pulls input data from the hvac section?  if that's even data possible for equest to pull ...

or you could parse the info from the .sim file keying on just the = system name, heat-sizing-rati & cool-sizing-rati variables.

"PSZ-1" = SYSTEM
   TYPE             = PSZ
   HEAT-SOURCE      = FURNACE
   ZONE-HEAT-SOURCE = NONE
   BASEBOARD-SOURCE = NONE
   SIZING-RATIO     = 1.15
   HEAT-SIZING-RATI = 1.25
   COOL-SIZING-RATI = 1.15
  etc ........



On 4/10/13 1:04 PM, Nick Caton wrote:
Hi folks,

I have a seemingly simple LEED comment which has been causing me to chase my tail this afternoon.  I feel like this should be really easy to document in a crystal-clear fashion, but I must be missing something:

The Task:
Document with clarity that the baseline system cooling and heating capacities are using the 1.15 and 1.25 (respectively) capacity sizing ratios as prescribed in 90.1 Appendix G.

Intuitively, I have a sense we should be able to simply and directly reference one or a series of the *.SIM reports to substantiate the systems are oversized by the appropriate factors.  After spending some time digging through the reports and associated help documentation however, I'm empty-handed and do not think the actual ratio inputs (COOL-SIZING-RATI / HEAT-SIZING-RATI) are reported.

Further, I tried deriving the oversizing ratio between a system's annual PEAK  (re: report SS-P) and calculated system capacity (report SV-A) as reported... but the math doesn't quite work out!  It's the right ballpark, but I don't think I can write the difference off as a rounding error...

The Solution(?):
For now, I can just provide screen grabs illustrating the inputs in eQuest's spreadsheet view with relative ease, but if this is possible to document by assembling/referencing one or more additional reports for future models I'd prefer to adopt that in practice and avoid the same question down the road.  If I have some misunderstanding or new nuance to learn about the reports that would be worthwhile as well =).

Any suggestions/experience?

Thanks in advance!

~Nick



NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036<tel:913.344.0036>
fax 913.345.0617<tel:913.345.0617>
www.smithboucher.com<http://www.smithboucher.com>



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