[Bldg-sim] Vestibule Modeling

[RobertWichert]

In my original post I said "Since LEED requires compliance with ASHRAE 
90.1 Mandatory measures...".  I believe this is correct, at least as far 
as Architectural, Mechanical and Electrical mandatory requirements are 
concerned.

And yes, I realize that there are exceptions for doors not used as 
entries (emergency only or exit only?) and for doors leading into spaces 
less than 3000 sq. ft.  Also for buildings less than four stories under 
10,000 sq. ft. in CZ 3 or 4.  And for mild climates.  I do not believe 
any of these would apply to the building I am working on, but I do 
appreciate the options. Including revolving doors!


Robert Wichert P.Eng. LEED AP BD&C
+1 916 966 9060
FAX +1 916 966 9068







===============================================

On 7/31/2013 11:50 AM, Nick Caton wrote:
> [Bldg-sim] Vestibule Modeling
>
> I concur with the advice to read the requirements more carefully – in 
> almost no case is a vestibule required at every door, when they are 
> required.
>
> Take care and recognize that an Appendix G model is NOT a method to 
> show code compliance.  It’s a procedure for benchmarking the building 
> performance for design which exceeds the minimum requirements of the 
> standard.  The first sections of Appendix G provide a concise overview.
>
> You can evaluate the effect a vestibule or not as already discussed – 
> in function this should simply reduce scheduled infiltration.  That 
> said, I do not believe any Appendix G model should have the proposed 
> and baseline models differing with respect to having a vestibule.  I 
> think table G3.1 is pretty clear that the baseline model is to match 
> the proposed with respect to space/thermal block configuration and 
> arrangement.
>
> Finally, just to drive an extra wedge into the commentary – while the 
> specified mandatory sections (#.4…) ARE required of the design for a 
> LEED project, to pass EAp2, in my humble opinion it’s incorrect (or at 
> least a stretch) to say LEED requires demonstrating compliance with 90.1.
>
> In sum, to the extent vestibules are required (review the sections and 
> exceptions carefully), a LEED project must by design include them in 
> the proposed design.  In turn, the proposed model should incorporate 
> the vestibule in the form of a distinct thermal block (zone/space), to 
> match the actual design.  In turn, the same edits should be applied to 
> the baseline model as it’s supposed to match the proposed model in 
> this regard.
>
> If the vestibules will be designed to be conditioned by the same 
> systems handling the surrounding spaces, you might make the case that 
> it’s a reasonable thing to not model them explicitly as a separated 
> space (modeler has the prerogative to identify and assert where such 
> spatial approximations are appropriate), but in preliminary LEED 
> submission I’d advise making that decision and case clear to the 
> reviewer in your documentation so if it isn’t acceptable you have the 
> opportunity to make the corrections per above prior to final submission.
>
> ~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:*bldg-sim-bounces at lists.onebuilding.org 
> [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Jim Dirkes
> *Sent:* Tuesday, July 30, 2013 10:25 AM
> *To:* 'RobertWichert'; 'bldg-sim at lists.onebuilding.org'; 
> 'equest-users at lists.onebuilding.org'
> *Subject:* Re: [Bldg-sim] Vestibule Modeling
>
> Robert,
>
> Did you notice the 7 exceptions to section 5.4.3.4?  One of them may 
> apply to you…
>
> As far as modeling goes, a vestibule is principally an infiltration 
> control technique, so I suppose that you could argue for reduced 
> infiltration when vestibules are present. I am unaware of any research 
> or other information about how they may affect infiltration.  Since 
> infiltration is such a guessing game, I never apply any special curves 
> for vestibules.
>
> p.s., the IECC 2012 (Int’l Energy Conservation Code) includes 
> mandatory envelope and infiltration testing and criteria. This will 
> probably be a game changer for the construction industry in areas that 
> adopt this code and will definitely affect the energy models prepared 
> for those projects.
>
> *James V Dirkes II, PE, BEMP, LEED AP**
> **www.buildingperformanceteam.com* 
> <http://www.buildingperformanceteam.com/>*
> **Energy Analysis, Commissioning & Training Services**
> *1631 Acacia Drive, Grand Rapids, MI 49504 USA
> 616 450 8653
>
> *From:*bldg-sim-bounces at lists.onebuilding.org 
> <mailto:bldg-sim-bounces at lists.onebuilding.org> 
> [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of 
> *Rosenberg, Michael I
> *Sent:* Tuesday, July 30, 2013 11:16 AM
> *To:* 'RobertWichert'; 'bldg-sim at lists.onebuilding.org'; 
> 'equest-users at lists.onebuilding.org'
> *Subject:* Re: [Bldg-sim] Vestibule Modeling
>
> Any of the mandatory requirements in Standard 90.1 must be included in 
> your building design and cannot be traded off using a performance 
> approach.
>
>
>
> ____
>
> ______________________
>
> Michael Rosenberg, CEM, LEED AP
> Senior Research Scientist
> ENERGY & ENVIRONMENT DIRECTORATE
>
> Pacific Northwest National Laboratory
> 2032 Todd Street
> Eugene, OR 97405
> (541) 844-1960
> michael.rosenberg at pnnl.gov <mailto:michael.rosenberg at pnnl.gov>
> www.pnnl.gov <http://www.pnnl.gov>
>
>
>
> -----Original Message-----
> *From: *RobertWichert [robert at wichert.org <mailto:robert at wichert.org>]
> *Sent: *Tuesday, July 30, 2013 08:08 AM Pacific Standard Time
> *To: *bldg-sim at lists.onebuilding.org 
> <mailto:bldg-sim at lists.onebuilding.org>; 
> equest-users at lists.onebuilding.org 
> <mailto:equest-users at lists.onebuilding.org>
> *Subject: *[Bldg-sim] Vestibule Modeling
>
> I see that ASHRAE 90.1 requires a vestibule in most cases, but I don't
> know if it is modeled or if it is just mandatory.  It would seem to me
> that if it was modeled, showing compliance using modeling, without a
> vestibule, would be OK (you would make it up somewhere else in the
> envelope).  Does anybody know if the vestibule is modeled anywhere, and
> how to take it out or put it in?
>
> Since LEED requires compliance with ASHRAE 90.1 Mandatory measures, this
> makes a vestibule a mandatory requirement unless I can model it with and
> without.  If this is even possible.
>
> Otherwise we must put in a vestibule to comply with LEED.
>
>
> Is this correct?  Does anybody have other thoughts or ideas?  We have a
> very efficient building, modeled without the vestibule in Climate Zone
> 3B.  I would think that we could take a heating penalty and not install
> a vestibule AT EVERY DOOR.
>
>
> I appreciate your thinking about this.
>
>
>
> --
> Robert Wichert P.Eng. LEED AP BD&C
> +1 916 966 9060
> FAX +1 916 966 9068
>
>
>
>
>
>
>
> ===============================================
>
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