[Equest-users] Nat Vent and Unment Load hrs

[Nick Caton]

Christie – it’s kinda hard to evaluate possible causes without more details, but I can suggest a few things:

 

The % number  and the “Hours above/below” figures on BEPS/BEPU are on different metrics, IIRC  (“% of hours fans on” vs. “hours of the year”).  That they disagree to this extent may mean you have many “undercooled” hours occurring when you’ve dictated the fans are off.   You should be able to identify which zones are having the trouble, then for a specific zone in which hours of the day those are occurring between the different SIM reports – I can’t recount which ones exactly from memory, but SS-R/F/O comes to mind – maybe others…?

 

If that’s the case, then it could be a simple matter of reviewing  your t-stat setpoints in the respective schedules and ensuring setback temps are happening when you intend them to.  You might also ask yourself what should be happening with regard to morning warmup and see if that’s reflected in your model as well.

 

If the underheated/cooled hours are occurring in the middle of the day – that may conversely be a sign of inadequate capacities (heating/cooling/airflow), in which case I’d start by reviewing airflow-related scheduling and specified quantities.

 

The “detailed simulation reports summary” PDF under the help menu is a good starting point to help you see what clues the SIM reports can give.  Note you can ‘ctrl+f’ through it to find topics/reports of interest.  

 

Try seeing what you can learn from the SIM reports, and post again with your findings if after that you’re still stuck for ideas as to what might be off ;).

 

~Nick

 

 

 

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 Rimes, Christie
Sent: Tuesday, August 30, 2011 11:44 AM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] Nat Vent and Unment Load hrs

 

Hi all,

 

So a follow up then to how unmet load hours are calculated. I have a naturally ventilated office building that I have the fans running from 7am-5pm Mon-Fri. I also have the fans “cycling on any”. The SS-R reports show that the unmet load hours for cooling are really low however below the unmet load hours for cooling is 2781. This is impossible with only 9.42% hours outside the throttle range. Could someone help me reduce this number?

 

 

 

 

Christie Rimes, LEED BD+C

Designer

WSP ▪ FLACK + KURTZ

405 Howard Street, Suite 500

San Francisco, CA 94105

Direct: 415.402.2727 | Main: 415.398.3833

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

 

Ensuring that today’s built environment preserves the natural environment in which we all live.

 

We are WSP. United by our difference.

 

WSP is one of the world’s fastest-growing design, engineering and management consultancies. Specializing in property, transport and environmental projects, we work with clients to create built and natural environments for the future.

 

CONFIDENTIAL
This e-mail is confidential to the named recipient. If you have received a copy in error, please destroy it. You may not use or disclose the contents of this e-mail to anyone, nor take copies of it. The only copies permitted are (1) by the named recipient and (2) for the purposes of completing successful electronic transmission to the named recipient and then only on the condition that these copies, with this notice attached, are kept confidential until destruction

 

 

 

 

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20110901/61fe78cb/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 1459 bytes
Desc: image002.jpg
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20110901/61fe78cb/attachment.jpeg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/jpeg
Size: 20133 bytes
Desc: image003.jpg
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20110901/61fe78cb/attachment-0001.jpeg>