[Equest-users] Revert efficiencies to autosize from detailed?

[Nick Caton]

Nathan is quicker on the draw =).  Here's my response as assembled prior to his flying finish - I think I get through his bullets 1 + 2, and I've nothing to add to his answers for 3 & 4:

This is not a knock on anyone, but I advise at the outset to take GBCI review commentary with a grain of salt, particularly when it concerns means/methods specific to eQuest or any given software package.

My baseline models normally include manually entered efficiencies and autosizing capacities (cooling, heating, airflow) - I do not see anything wrong in that.  I am further personally unaware of any 90.1-baseline approach that relies on utilizing eQuest defaults for cooling/heating/fan efficiencies - to my knowledge there is no direct correlation between what eQuest wizards suggest for default efficiencies and any particular vintage of 90.1.  I understand these should all be manually entered, after performing separate baseline fan power and efficiency calculations per 90.1 appendix G.  My preference (and I think, the normal) is to use kW/CFM inputs for fans over the motor efficiency option.

If you aren't sure how to verify the effects of overriding manually entered heating/cooling/fan efficiencies, then I hesitate to recommend any course of action before pursuing that understanding first.  Otherwise you can only be shooting in the dark.

An informed course of action, in an auditing role, would involve reviewing or better performing the calculations yourself from scratch for Pfan and corresponding cooling/heating efficiencies, then comparing your results against what the modeler assembled and input, thus identifying and correcting any faults directly.

LEED baseline requirements never shift to anything more strict than the appropriate vintage of 90.1.  You can choose, at your option, to reference and document compliance with "qualifying energy codes" for EAp2 if I recall the present template language correctly, but nothing mandates doing so over 90.1.  If a team should choose to design a building to meet/exceed 90.1-2010 or Title 24, that does not mean a LEED v3 baseline is anything better or more stringent than as prescribed in 90.1-2007.

~Nick
[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] On Behalf Of Nathan Miller
Sent: Tuesday, June 12, 2012 3:38 PM
To: 'Laura Howe, RCE'; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Revert efficiencies to autosize from detailed?

Laura,

Many questions here, so I will try to respond succinctly to each, but forgive me if I am a little short on details.


1)      eQUEST WILL NOT default to the proper 90.1 baseline efficiency or fan power for your systems. You need to look up the appropriate EER (or COP, or whatever) and convert it to the proper EIR (unitless) efficiency to input in eQUEST. However, to further complicate things, if the 90.1 baseline efficiency includes system fan-power, you need to separate out that fanpower from the EIR rating and input the fanpower separately. There has been much discussion of this even in the past week on the forums, so I recommend doing some searches for "separating fan power" or the like.

2)      Yes, use the defined 90.1 Appendix G baseline even if local code is more stringent. Consider it a nice little bonus of working on projects with strict energy codes.

3)      System 4 (PSZ-HP) should have constant volume fans. You are taking a penalty if they were made variable speed in the baseline.

4)      You can edit the project name by opening the .inp file in a text editor, and changing the "Title" field. Then save the .inp, reopen in eQUEST and it should be good to go.

[cid:image003.png at 01CD48B2.88BBF3D0]

Nathan Miller, PE, LEED AP BD+C
Mechanical Engineer/Senior Energy Analyst
O 206-285-7100 | D 206-788-4577
www.rushingco.com<http://www.rushingco.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 Laura Howe, RCE
Sent: Tuesday, June 12, 2012 1:11 PM
To: equest-users at lists.onebuilding.org<mailto:equest-users at lists.onebuilding.org>
Subject: [Equest-users] Revert efficiencies to autosize from detailed?

HI All-

While there are some posts similar to this issue, I want to ask the group for clarification for a slightly different application.  Please bear with me for some assistance, I'd sure appreciate it!

I am working on someone else's model that has had comments back from GBCI for a LEED project. The model came to me in detailed mode.  They note that in the baseline model apparently non-90.1 baseline efficiencies were used.  Looking at the model, it does seem that the modeler manually entered efficiencies (they are in red) and they do not seem to be correct (even the GBCI comment notes this).  They are less efficient than 90.1. In some of the similar threads on this topic, someone mentioned that you can revert to autosizing by right clicking on the heating and cooling capacity and selecting "restore default".  Since the modeler did not manually input system size, just system efficiency (both cooling and heating hp eff, fan design kw/cfm and total eff frac seem to be manually entered), my question is if I restore those efficiency values to default (using right clicking), will Equest use the proper efficiencies and I'm good to ho?  I've done this, and it seems to work, although I'm not experienced enough to truly verify this.

When I compare the two models (original base and my reverted base) I do see where the power demand has dropped (SV-A), and none of the peak loads have changed (LS-A) but the equipment sizing (SV-A) has increased.  This all seems correct, do others think I am on track here?  Using the correct methodology?

If I can also confirm another question, LEED specific.  I understand 90.1 is the only appropriate base case for LEED even in Washington state, even if portions of their energy code are more stringent, correct?  The requirement to achieve a 10% reduction is how I think LEED addresses more stringent state codes so the base doesn't need to be written specific to those (numerous) state codes.  Correct? One comment from the client leads me to think that complying with WA code might explain the difference in equipment efficiencies used in the base case, and even though it doesn't add up I want to confirm my understanding.

Another issue that further confuses this is that the modeler apparently chose two of the systems to be variable speed (all are system type 4, constant volume in 90.1) and I'm not sure why.  The original modeler is not available for questioning.  Any ideas?  The VFD's were applied to an office space and data/server room packaged heat pumps, but not a large storage space.  Based on what I know right now, it seems those should be modeled constant volume.  If I'm updating the base model, I think it makes sense to correct this if the base incorrectly models a more efficient system.

Lastly, can anyone tell me how to change the project descriptor at the top left of the sim reports?  It's got some boilerplate name and it sure would be nice to have the filename show, or at least a single descriptor I can update in each model run.

Thanks so much-
Laura
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