[Equest-users] Unmet Hours

[Nick Caton]

[For continuity, I'm attaching Michael's most recent response to
Dakota's followup... just some convulted copy/pasting to keep the
discussion moving in one direction]

 

Michael,

 

I'd like to caution you against a fairly common misinterpretation.  90.1
is unfortunately not crystal clear, but the general consensus on these
lists (including reviewer input) is that 90.1 is citing unmet hours as
"coincidental" unmet hours.  The long and short of it is, you aren't
supposed to literally sum up the unmet heating and cooling hours of each
zone to come up with total unmet hours, even though it may seem
intuitive.  If you do, you're likely unnecessarily penalizing one or
both models and putting extra work on yourself.  See the message copied
below (scroll to the bottom and read-on-up) for a more in-depth
explanation/discussion of a "best practice" approach with eQuest -
there's more where that came from in the archives also.

 

~Nick

 

 

 

NICK CATON, E.I.T.

PROJECT ENGINEER

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

Check out our new web-site @ www.smithboucher.com 

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of M.
Shields
Sent: Tuesday, July 27, 2010 2:59 PM
To: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Unmet Hours

 

Nick,

 

My baseline model currently has 0 unmet hours, and my proposed has
around 100 total if I add up all of the unmet hours in all zones.  From
my interpretation (and I believe you're confirming it) this does not
qualify.  If I read 90.1 correctly then there is no weighting or
averaging, it's just a total unmet hours anywhere in the building (ie
zone 1 hours +zone 2 hours +zone 3 hours.... Etc).  Does anyone else
disagree with this interpretation?

 

Thanks,

Michael

 

 

 

From: Dakota Kelley [mailto:dakotak at teliospc.com] 
Sent: Tuesday, July 27, 2010 3:52 PM
To: Nick Caton; M. Shields; equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] Unmet Hours

 

I put one small FYI at the end of Nick's #3 below, in all caps for the
sake of the plain text archives...

 

Dakota

 

 

From: Nick Caton [mailto:ncaton at smithboucher.com] 
Sent: Tuesday, July 27, 2010 2:33 PM
To: M. Shields; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Unmet Hours

 

Michael, 

 

90.1's passage (G3.1.2.2) regarding unmet hours requirements is
something I had to re-read many times to get my head fully wrapped
around it... Here's my current interpretation:

 

1.       You need to have 300 or fewer hours in each model.

2.       The proposed is not allowed to perform worse than the baseline
by more than 50 unmet hours.  If it does you have to make the baseline
"underperform" so they're within 50 of each other. 

3.       The baseline is permitted to perform worse than the proposed
(by any degree) as long as it's still 300 or fewer unmet hours. THIS IS
MY INTERPRETATION AS WELL, BUT IT IS WORTH MENTIONING THAT MORE THAN ONE
LEED REVIEWER HAS INDICATED THE OPPOSITE.  FOR EXAMPLE, I WAS TOLD I WAS
OUT OF COMPLIANCE WHEN THE BASELINE HAD 65 UNMET COOLING HOURS AND THE
PROPOSED HAD 5 UNMET COOLING HOURS.  DO YOU ARGUE, OR JUST REDUCE THE
BASELINE HOURS?  IT PENALIZES THE BASELINE TO REDUCE THOSE HOURS, SO I
WENT AHEAD AND DID WHAT I WAS TOLD.    

 

You haven't said whether you're talking about your baseline or proposed
model, but the above points should guide you as to whether you need to
make an adjustment.  Refer to G3.1.2.2 for review and further info.

 

~Nick

 



 

NICK CATON, E.I.T.

PROJECT ENGINEER

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

Check out our new web-site @ www.smithboucher.com 

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of M.
Shields
Sent: Tuesday, July 27, 2010 1:19 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Unmet Hours

 

Hi All,

 

I am working on filing out the LEED paperwork for submittal and for
unmet hours I am wondering does the reviewer want the total unmet load
hours for the building, or an average per zone?  My building has about
100 zones, most of which have 0 unmet hours, but I have one zone which
has significant (more than 50) unmet hours.  Does this mean my model
exceeds the requirement that the difference between the baseline and the
proposed be less than 50 hours?

 

Thanks for any advice.

 

Michael Shields

Phone: 803-493-4507
Fax: 803-548-2511
Email: mshields at fstrategies.com

 

 

***

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Nick
Caton
Sent: Tuesday, July 06, 2010 1:53 PM
To: Andrew T McMurray; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] (no subject)

 

There's much discussion on this in the archives, but basically the
difference is that BEPS/BEPU is reporting % of coincidental unmet hours
(when multiplied by the annual hours fans on in report SS-E), as we
intuitively think of it, whereas the SS-R reports are reporting unmet
hours for each zone without regard to coincidental unmet hours.  Summing
the SS-R reports may be the more intuitive approach, but you'll end up
with a conceptually different figure that can often be higher than the
figure found through BEPS/SS-R.

 

Note there's a degree of rounding involved when you only get a
percentage to so many decimal places.

 

As an example, if you had an imaginary model with only two zones which
were unmet all year long, BEPS would report 100% hours outside
throttling range, whereas adding up the SS-R report hours might lead you
to believe there are as many as 8,760*2 = 17,520 hours per year.

 

Therein lies the answer to why the numbers don't sync up after adding up
the SS-R figures.  For now, multiplying the BEPS figure by the annual
hours fans on is the best approach imho for documenting compliance with
the baseline/proposed unmet hours requirements.

 

It's been said the next released version of eQuest will present this
information more clearly in the BEPS/BEPU reports.

 

~Nick

 



 

NICK CATON, E.I.T.

PROJECT ENGINEER

25501 west valley parkway

olathe ks 66061

direct 913 344.0036

fax 913 345.0617

Check out our new web-site @ www.smithboucher.com 

 

From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Andrew
T McMurray
Sent: Tuesday, July 06, 2010 1:17 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] (no subject)

 

Hello Everyone,

 

I am trying to finalize a building model for a LEED submission but am
having difficulty getting the BEPS report "percent of hours any system
zone outside of throttling range" to match the SS-R reports "zone under
heated" and "zone under cooled" hours.  This was a complaint from the
LEED reviewer.

 

The building has three systems and all spaces are conditioned.  The BEPS
report lists hours outside of throttling range at 2% (175hrs), but the
SS-R report lists under heated and cooled hours of 280 (3.2%).  

 

I consider myself fairly familiar with equest but am unable to get these
two numbers to match.  Has anyone run into this problem in the past or
have any ideas of where I should be focusing my attention?

 

Many Thanks,

 

 

Andrew McMurray, EIT
P. A. Collins PE Consulting Engineers
15 West 26th Street, 5th Floor
New York, NY 10010
 
tel: 212.696.5294
fax: 212.696.5295
www.pacollinspe.com

 

 

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