[Equest-users] URGENT: Window U-values: Total window assembly v/s Glass only

Joe Huang yjhuang at whiteboxtechnologies.com
Wed Aug 3 12:57:10 PDT 2011


In the simple window model, all the bulk properties, chiefly U-factor and SHGC, are 
smeared over a single monolithic layer.  The main source
of discrepancy from the detailed layer-by-layer model, however, are not the bulk 
properties, but the angular properties of the window.

Joe Huang
White Box Technologies, Inc.
346 Rheem Blvd., Suite 108D
Moraga CA 94556
yjhuang at whiteboxtechnologies.com
www.whiteboxtechnologies.com
(o) (925)388-0265
(c) (510)928-2683
"building energy simulations at your fingertips"


On 8/3/2011 12:26 PM, Arpan Bakshi wrote:
> One thought about the 0-frame and NRFC modeling method is, what about the additional 
> visible light transmissive areas for what would have been opaque frame and is now glass? 
> Do others simply apply the same SHGC from COG properties to the frame, now that the 
> assembly is monolithic?
> Arpan
>
>
> On Wed, Aug 3, 2011 at 3:16 PM, Joe Huang <yjhuang at whiteboxtechnologies.com 
> <mailto:yjhuang at whiteboxtechnologies.com>> wrote:
>
>     This is an interesting thread that's related to a topic that has been going around
>     in ASHRAE TC 4.7 for almost four years, so I'd like to add my two-cents.
>
>     1. I've always understood that the fenestration requirements in ASHRAE 90.1 are for
>     the whole assembly, i.e., fenestration + frame.
>     2. The NFRC rated values are also for the whole assembly, but those bulk property
>     values are insufficient for modeling because (a) they do not indicate the angular
>     properties of the glazing,  (b) they do not distinguish between center-of-glass,
>     edge-of-glass, or frame.
>     3. If the detailed fenestration description is available, one can model it in
>     WINDOW-5/6 and produce a WINDOW-5 file (or what the WINDOW-5 people call the "DOE-2
>     file"!) and use that in DOE-2/eQUEST.
>     4. If the detailed fenestration description is not available, one can model it using
>     the simple monolithic window model in DOE-2, but the results may differ
>     substantially from 3, particularly for complex glazing systems; under no
>     circumstances should comparisons be done mixing the two methods, i.e., comparing a
>     window modeled  using WINDOW-5/6 and another modeled using the simple window model.
>
>     So, this gets to the topic floating around in ASHRAE TC 4.7 (Energy Calculations):
>
>     5. Although 3 is the most desirable approach, there are many instances where it's
>     unfeasible, either because
>     only the bulk properties have been defined, e.g., for ASHRAE 90.1 or Title-24, or
>     the detailed fenestration descriptions are not available, as in an existing
>     building.  For those instances, would it be helpful to have a computer program that
>     would "reverse engineer" the layer-by-layer description of the fenestration based on
>     its bulk properties (assembly U-factor, SHGC) and any other obtainable details,
>     e.g., number of panes, gap thickness, frame material type, etc. ?   A number of us
>     within TC 4.7 have felt "yes", but I thought I'd canvas people on this thread on
>     what you think.
>
>     Please send me e-mail if you wish to see the draft Work Statement.
>
>     Joe
>     (former TC 4.7 Research Subcommittee Chair)
>
>     Joe Huang
>     White Box Technologies, Inc.
>     346 Rheem Blvd., Suite 108D
>     Moraga CA 94556
>     yjhuang at whiteboxtechnologies.com  <mailto:yjhuang at whiteboxtechnologies.com>
>     www.whiteboxtechnologies.com  <http://www.whiteboxtechnologies.com/>
>     (o)(925)388-0265  <tel:%28925%29388-0265>
>     (c)(510)928-2683  <tel:%28510%29928-2683>
>     "building energy simulations at your fingertips"
>
>
>     On 8/2/2011 11:23 AM, Brad Robinson wrote:
>>     There are, it seems, a multitude of ways people on this forum go about modeling
>>     windows. It would be interesting to know, in terms of a LEED review, what others
>>     have been required to provide in terms of modeling the windows. Does anyone have
>>     experience on the Canadian side of the border what is required?  Thanks.
>>
>>     Brad Robinson
>>
>>     *From:* R B <slv3sat at gmail.com> <mailto:slv3sat at gmail.com>
>>     *To:* eQUEST Users List <equest-users at lists.onebuilding.org>
>>     <mailto:equest-users at lists.onebuilding.org>
>>     *Sent:* Saturday, July 30, 2011 11:29:31 PM
>>     *Subject:* Re: [Equest-users] URGENT: Window U-values: Total window assembly v/s
>>     Glass only
>>
>>     Came across this in eQuest help - basically suggests to use zero frame width.
>>     -Rohini
>>     Volume 2: Dictionary> Envelope Components> WINDOW> Window Frames and Skylight Curbs
>>
>>
>>               FRAME-WIDTH
>>
>>     Projected width of the frame in the plane of the glazing (Figure 27). We recommend
>>     that frames be entered only if the frame area is more than 10 percent or so of the
>>     glazed area, which is generally only the case in residential applications. The
>>     program assumes that the frame width is the same on all sides of the window. If
>>     this is not the case, use the average frame width.
>>
>>
>>     On Fri, Jul 29, 2011 at 4:15 PM, Alex Krickx <akrickx at seriousenergy.com
>>     <mailto:akrickx at seriousenergy.com>> wrote:
>>
>>         Great thread-
>>         To answer Vikram’s question - When using WINDOW, you are slightly limited in
>>         the output file (for example, if I create an NFRC-type model to figure out
>>         U-value for a curtainwall system, I will need to simply the window to export it
>>         into a DOE-2 report format). When you do import a WINDOW Report for DOE-2 into
>>         eQUEST it does not load any frame information with it – it presents the COG
>>         glass performance. My process is to adjust the spacer type and frame
>>         width+conductance to make an object that matches what WINDOW tells me my window
>>         performance is.
>>         I don’t model for LEED, so am less familiar with what is required for that –
>>         since I work for a window manufacturer I usually have access to all the data I
>>         need to determine frame-inclusive u-value and SHGCs, i.e. no need to rely on
>>         90.1 defaults.
>>         Since the conversation was about using NFRC data – let me ask this question:
>>         NFRC data for windows (curtainwall assemblies included) is for a “default”
>>         size. I believe for curtainwall a mulled unit is modeled at 2m x 2m (or 78.54”
>>         x 78.54”) – as shown below:
>>         This is an example, but let’s say that the NFRC value is U-0.34. If your
>>         building has a smaller or larger window (which will change the glass-to-frame
>>         ratio) the U-value will be different.
>>         Is it still appropriate to use the NFRC value in that case, where it is entered
>>         as a frame-inclusive U-factor and SHGC? I’m curious as to how others approach
>>         this issue when dealing with models for compliance.
>>         Kind regards,
>>         Alex Krickx
>>         Alex Krickx, LEED AP
>>         Building Energy Specialist
>>         Serious Energy, Inc.
>>         1250 Elko Dr, Sunnyvale, CA 94089
>>         (t) 408.541.8124
>>         akrickx at seriousenergy.com <mailto:akrickx at seriousenergy.com>
>>         /The information contained in this e-mail and any attachments may be
>>         confidential, proprietary and/or privileged. If you are not the intended
>>         recipient then you have received it in error and any review, distribution or
>>         copying of this message and any attachments is prohibited and you are to notify
>>         the sender immediately by reply e-mail and delete immediately this message and
>>         any attachments./
>>         *From:*equest-users-bounces at lists.onebuilding.org
>>         <mailto: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 *Sami, Vikram
>>         *Sent:* Friday, July 29, 2011 1:39 PM
>>         *To:* Robby Oylear; Bill Talbert; Carol Gardner
>>
>>         *Cc:* equest-users at lists.onebuilding.org
>>         <mailto:equest-users at lists.onebuilding.org>
>>         *Subject:* Re: [Equest-users] URGENT: Window U-values: Total window assembly
>>         v/s Glass only
>>         Firstly – congratulations to all contributors – I think this is probably the
>>         first time (that I recall) that all of the posts on this list have been on a
>>         single thread. I couldn’t resist being a part of this so I’m going to add my 2
>>         cents:
>>         90.1 baseline values & SHGC are assembly u-values so your frame needs to be
>>         calculated into this. To get the derated value – you could either use the handy
>>         little XL spreadsheet that comes with the install of eQUEST (under the
>>         data\window folder) called eQUEST-DOE2 Glass Library.xls. This gives you COG
>>         values *AND *glass+frame NFRC values. They have separate table where it is
>>         sorted by U-value and SHGC – I use it all the time (screenshot below).
>>         So you can select your values in conjunction with the values below from the
>>         DOE2 help file to get what you need.
>>         *
>>         Frame Type*
>>         	
>>         *FRAME-CONDUCT (excludes OA film)*
>>         	
>>         *
>>         U-value^a *
>>         Thermally unbroken aluminum
>>         	
>>         3.037 (17.24)
>>         	
>>         1.90 (10.79)
>>         Thermally broken aluminum
>>         	
>>         1.245 (7.07)
>>         	
>>         1.00 (5.68)
>>         External flush glazed aluminum
>>         	
>>         0.812 (4.61)
>>         	
>>         0.70 (3.97)
>>         Wood with or without cladding
>>         	
>>         0.434 (2.46)
>>         	
>>         0.40 (2.27)
>>         Vinyl
>>         	
>>         0.319 (1.81)
>>         	
>>         0.30 (1.70)
>>         ^a U-value includes OA film at 15 mph [6.7 m/s] windspeed
>>           FRAME-CONDUCT = [(U-value)^-1 - 0.197]^-1 Btu/ft2-F-h
>>           FRAME-CONDUCT = [(U-value)^-1 - 0.035]^-1 W/m2-K
>>
>>         **
>>         Alternately, you can select a COG value to match what you want, set your frame
>>         to zero and your spacer to UE-EQ-UC (this will give you a uniform COG
>>         conductance across the assembly).
>>         I am curious about LBNL window imports. When you set up your assembly in window
>>         – it includes frames, but you import it in as a glass type – should you zero
>>         out the frame (as in the second case) if you import from window?
>>         **
>>         *Vikram Sami*, LEED AP BD+C
>>         Sustainable Design Analyst
>>         1315 Peachtree St. NE, Atlanta, GA 30309
>>         t: 404-443-7462    f: 404.892.5823     e: vikram.sami at perkinswill.com
>>         <mailto:vikram.sami at perkinswill.com> www.perkinswill.com
>>         <http://www.perkinswill.com/>
>>         *Perkins+Will.*Ideas + buildings that honor the broader goals of society
>>         *From:*equest-users-bounces at lists.onebuilding.org
>>         <mailto: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 *Robby Oylear
>>         *Sent:* Friday, July 29, 2011 4:18 PM
>>         *To:* Bill Talbert; Carol Gardner
>>         *Cc:* equest-users at lists.onebuilding.org
>>         <mailto:equest-users at lists.onebuilding.org>
>>         *Subject:* Re: [Equest-users] URGENT: Window U-values: Total window assembly
>>         v/s Glass only
>>         From the 90.1 User's Manual pg 5-12:
>>         "With Addendum 90.1ag (published
>>         with Standard 90.1-2001) glazed wall
>>         systems, including glass curtain walls used
>>         on large buildings, storefront glazing
>>         systems, and other similar products that
>>         are assembled at the construction site, as
>>         opposed to at the factory, must either be
>>         rated using NFRC procedures or the
>>         default U-factor, SHGC and VLT from
>>         Table A8.2. Since the performance values
>>         in Table A8.1A are based on uncoated
>>         clear glass in poorly performing metal
>>         frame, they do not offer any credit for
>>         low-e coatings, thermal break frames or
>>         any other advanced feature. In general,
>>         values from Table A8.1A will not achieve
>>         compliance with the fenestration
>>         requirements.
>>         The NFRC procedure for site-built
>>         fenestration is described in NFRC 100.
>>         The NFRC ratings are based on computer
>>         simulations of various product options at
>>         standard sizes. (For curtain walls, the
>>         standard size specified is 2000 mm by
>>         2000 mm, or approximately 79 in. by 79
>>         in.) Multiple glass options can be included
>>         in one simulation matrix. The entire
>>         simulation matrix is then validated by a
>>         single physical test at the standard size. If
>>         the matrix for a product has previously
>>         been validated, then a new glass option
>>         can be added to the matrix by simulation
>>         alone. Simulations and tests must be done
>>         by an NFRC-accredited simulation and
>>         test laboratories."
>>         Also, the LEED Reference Guide for Green Building Design and Construction, pg
>>         275 specifically references Tables A8.1 and A8.2 or requires that the products
>>         be certified and labeled in accordance with NFRC.
>>         Not seeing any statements that would allow the modeler to perform their own
>>         fenestration assembly performance calculations.
>>         -Robby
>>         On Fri, Jul 29, 2011 at 12:02 PM, Bill Talbert <btalbert at aeieng.com
>>         <mailto:btalbert at aeieng.com>> wrote:
>>         Regarding Omar’s first question, I would also clarify that adding a frame to
>>         the baseline is probably not the correct approach unless you are adjusting the
>>         U-value to a center of glass value and accounting for the frame and edge
>>         effects such that the total fenestration performance is equal to the 90.1
>>         prescribed value.
>>         ‘They are silent about frames but I would use one, match the frame width of
>>         your proposed window. Use an Aluminum frame with no thermal break.’
>>         Baseline Table 5.5-1 through 5.5-8 specify ‘fenestration assembly’ values which
>>         include the effect of the frames and edge of glass. Modeling a frame in the
>>         Baseline will further degrade the overall fenestration U-value (unless your
>>         frame outperforms the glazing) and result in overestimating the savings
>>         relative to the fenestration performance. If you use the Table values for your
>>         window performance, frames shouldn’t be included. If you include a frame, you
>>         should create a 90.1 compliant product using WINDOW and use the appropriate
>>         frame and glazing performance values as eQuest inputs such that your overall
>>         frame and glazing performance matches the A90.1 Table value.
>>         Regards,
>>         Bill
>>         *Bill Talbert***PE, LEED® AP
>>         Sustainable
>>         	
>>         	
>>         *AEI*| AFFILIATED ENGINEERS, INC.
>>         5802 Research Park Boulevard | Madison, WI  53719
>>
>>         P: 608.441.6677 | C: 608.234.3803 | F: 608.238.2614
>>         btalbert at aeieng.com <mailto:btalbert at aeieng.com>  | *www.aeieng.com
>>         <http://www.aeieng.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
>>         <mailto:equest-users-bounces at lists.onebuilding.org>] *On Behalf Of *Carol Gardner
>>         *Sent:* Friday, July 29, 2011 1:35 PM
>>         *To:* Robby Oylear
>>
>>         *Cc:* equest-users at lists.onebuilding.org
>>         <mailto:equest-users at lists.onebuilding.org>
>>         *Subject:* Re: [Equest-users] URGENT: Window U-values: Total window assembly
>>         v/s Glass only
>>         This came off of the Window website:
>>         WINDOW 6.3 is a publicly available computer program for calculating total
>>         window thermal performance indices (i.e. U-values, solar heat gain
>>         coefficients, shading coefficients, and visible transmittances). WINDOW 6.3
>>         provides a versatile heat transfer analysis method consistent with the updated
>>         rating procedure developed by the National Fenestration Rating Council (NFRC)
>>         that is consistent with the ISO 15099 standard. The program can be used to
>>         design and develop new products, to assist educators in teaching heat transfer
>>         through windows, and to help public officials in developing building energy codes.
>>         On Fri, Jul 29, 2011 at 11:26 AM, Robby Oylear <robbyoylear at gmail.com
>>         <mailto:robbyoylear at gmail.com>> wrote:
>>         Carol,
>>         I have to take exception to this:
>>         "As far as NFRC, your Solarban glass data is NFRC rated which should be good
>>         enough, I think. It's rare in commercial buildings to have a rating for the
>>         entire window."
>>         From my first response:
>>         In order to meet LEED EAp2 Minimum Energy Performance, the project must comply
>>         with all mandatory provisions of ASHRAE 90.1-2007.  Section 5.4.2 Fenestration
>>         and Doors requires that fenestration performance be determined per section
>>         5.8.2.  Section 5.8.2.4 U-factor requires that the U-factor for the overall
>>         fenestration area (including framing) be determined in accordance with NFRC
>>         100. If you do not have NFRC data available, values from section A8.2 are the
>>         only acceptable alternative.
>>         NFRC values for the glazing alone not "good enough".  This is exactly what the
>>         reviewer is trying to get at.
>>         I'd hardly call NFRC certification rare.  In the State of Washington NFRC
>>         certification has been required for all glazing assemblies for over 10 years.
>>         How do you justify certifying that your projects have met the mandatory
>>         provisions of ASHRAE 90.1 without NFRC data?
>>         *Robby Oylear, LEED**^® **AP BD+C*
>>         /Mechanical Project Engineer/
>>         /Energy Analyst/
>>         //
>>         *D*206-788-4571 |*C*206-354-2721
>>         */www.rushingco.com/* <http://www.rushingco.com/>
>>         On Fri, Jul 29, 2011 at 11:12 AM, Carol Gardner <cmg750 at gmail.com
>>         <mailto:cmg750 at gmail.com>> wrote:
>>         On Thu, Jul 28, 2011 at 5:40 AM, Omar Katanani <omar at ecoconsulting.net
>>         <mailto:omar at ecoconsulting.net>> wrote:
>>
>>             Dear all,
>>             Thank you for your responses.
>>
>>                1. Are the NFRC testing and the values in table A8.2 used for the
>>                   Baseline, Proposed, or both scenarios?
>>
>>         For the baseline windows, Appendix G gives the following instructions:
>>         Fenestration
>>         U-factors shall match the appropriate requirements in Tables 5.5-1 through
>>         5.5-8. Fenestration SHGC shall match the appropriate requirements in Tables
>>         5.5-1 through 5.5-8.
>>         They are silent about frames but I would use one, match the frame width of your
>>         proposed window. Use an Aluminum frame with no thermal break.
>>
>>                2. Let’s say I do not have NFRC test results and decide to use the
>>                   values in table A8.2. For a clear double glazed and metal frame type,
>>                   I get an assembly U-factor of 5.1. How can I input this into eQUEST?
>>                   As far as I know, I can enter the glass properties and the frame
>>                   properties. Do I have to play with the glass properties and check the
>>                   LV-D report for the calculated Assembly u-value?
>>
>>         A U of 5.1 does not make sense. Are you sure this isn't R?
>>
>>             Similarly, for the baseline, Tables 5.5-1 to 5.5-8 of ASHRAE 90.1 provide
>>             the assembly u-values for vertical glazing. How can I enter these values
>>             into eQUEST?
>>
>>                3. I am attaching the specs of the proposed glazing. These numbers are
>>                   for the glass only (note that the u-values reported are NFRC ones).
>>                   Additionally, I know that the frame will be aluminium. Do I still
>>                   need NFRC U-values for the whole assembly, or is the NFRC usually for
>>                   the glass only? If yes, how can I calculate the whole assembly
>>                   U-value (given that eQUEST doesn’t have the ability to calculate this)
>>
>>
>>         For your proposed building I highly recommend you use LBNL's Window program. In
>>         it you can select your window type, e.g. casement, picture, etc,, select your
>>         glass from their glass library, which is huge and definitely includes Solarban,
>>         and then model your frame using whatever information the architect gives you
>>         related to thermal breaks and spacers. After you run your window in the program
>>         you can select to save it to a DOE 2 report which will automatically go into
>>         your DOE 2 Window folder. Then you just have to select it from the pull down menu.
>>
>>         Otherwise, input your glass values, as you are already, and input your frame
>>         data, the same data you got from your architect, and model it that way. When
>>         you look at your LV-D report you will likely see a variety of U values. That's
>>         because they will vary based on window size.due to the frame effect. You need
>>         to have a frame.
>>
>>         As far as NFRC, your Solarban glass data is NFRC rated which should be good
>>         enough, I think. It's rare in commercial buildings to have a rating for the
>>         entire window.
>>
>>         Carol
>>
>>             Thanks for clarifying this, as my project is outside the US and we are not
>>             too familiar with standards such as NFRC.
>>             Best regards,
>>             Omar
>>             ___________________________
>>             Omar Katanani
>>             Sustainable Design Engineer
>>             Email: omar at ecoconsulting.net <mailto:omar at ecoconsulting.net>
>>             EcoConsulting (Lebanon)
>>             Nahas Building, 4^th floor
>>             4 St-Maron Street / Georges Haddad Avenue
>>             Postal Code: 2028 5806 SAIFI
>>             Beirut, Lebanon
>>             Tel: +961 (0) 1 971 266
>>             Mobile: +961 (0) 3 045 045
>>             EcoConsulting (UK) Ltd
>>             28 Marshalsea Road
>>             London, SE1 1HF
>>             Tel: +44 (0) 207 939 0989
>>             Fax: +44 (0) 207 939 0981
>>             Website: www.ecoconsulting.net <http://www.ecoconsulting.net/>
>>             *From:*Robby Oylear [mailto:robbyoylear at gmail.com
>>             <mailto:robbyoylear at gmail.com>]
>>             *Sent:* 28 July 2011 00:53
>>             *To:* Omar Katanani
>>             *Cc:* Brad Robinson; equest-users at lists.onebuilding.org
>>             <mailto:equest-users at lists.onebuilding.org>
>>
>>             *Subject:* Re: [Equest-users] URGENT: Window U-values: Total window
>>             assembly v/s Glass only
>>             Omar,
>>             To directly answer your question:
>>             "I’m assuming that, given that I entered the u-values for the glass only,
>>             and then I entered information about the frame, then I need not worry about
>>             any conversions in U-values,  since eQUEST has all the necessary
>>             information to calculate the equivalent u-value of the whole pane + frame
>>             assembly, right?"
>>             No.  Your method will result in an assembly U-value based on your input
>>             glass conductance and whatever default frame properties that the eQUEST
>>             wizard will use.  I have never tried to let eQUEST determine an assembly
>>             value, as NFRC values are required for LEED and code compliance studies.  I
>>             would not be surprised if the values eQUEST is calculating (shown in LV-D
>>             and LV-E reports like previously mentioned) are much different than what
>>             you'll actually see in the test results.
>>             Again, NFRC values are a LEED requirement, so unless you're just doing
>>             preliminary analysis for a client, you need to receive NFRC simulation
>>             reports or certified product directory numbers in accordance with NFRC 100.
>>             *Robby Oylear, LEED^® AP BD+C*
>>             /Mechanical Project Engineer/
>>             /Energy Analyst/
>>             //
>>             *D*206-788-4571 |*C*206-354-2721
>>             */www.rushingco.com/* <http://www.rushingco.com/>
>>             On Wed, Jul 27, 2011 at 2:44 PM, <omar at ecoconsulting.net
>>             <mailto:omar at ecoconsulting.net>> wrote:
>>             Dear Robby,
>>
>>             Yes, I am modeling for LEED purposes.
>>             I'll look into A8.2. But at least, is my method correct for the proposed
>>             scenario?
>>
>>             Brad: I think you need to enter the center of glass u-value in the "Glass
>>             Type", and then enter the frame properties in the "Window" properties...
>>
>>             Best,
>>             Omar
>>
>>
>>             Quoting Brad Robinson <brad.robinson at yahoo.com
>>             <mailto:brad.robinson at yahoo.com>>:
>>
>>
>>
>>                 Is the u-value listed for a manufacturer and specific model on the
>>                 NRCAN website centre of glass or overall assembly?  Many windows are
>>                 custom made to suit so I am unclear if each individual custom window
>>                 would need to be tested.
>>
>>
>>
>>                 In eQuest, when entering the window, if the u-value represents the
>>                 whole window, including frame, do you need to enter a frame width,
>>                 conductance etc as well under the Window Frame section under Window
>>                 Properties?  Thanks.
>>
>>
>>                 Brad Robinson
>>
>>
>>
>>                 ________________________________
>>                 From: Robby Oylear <robbyoylear at gmail.com <mailto:robbyoylear at gmail.com>>
>>                 To: Omar Katanani <omar at ecoconsulting.net <mailto:omar at ecoconsulting.net>>
>>                 Cc: equest-users at lists.onebuilding.org
>>                 <mailto:equest-users at lists.onebuilding.org>
>>                 Sent: Wednesday, July 27, 2011 12:32:08 PM
>>                 Subject: Re: [Equest-users] URGENT: Window U-values: Total window
>>                 assembly v/s Glass only
>>
>>
>>                 Omar,
>>
>>                 The answer depends on the purpose of your study.  If you're trying to
>>                 get results for a client on the impact of the glazing on their energy
>>                 performance, this may be adequate.  Make sure you've entered in the
>>                 framing information properly (metal vs. non-metal).
>>
>>                 I'd recommend opening up your simulation output results file (xxxx.SIM)
>>                 and going to the either the last page of the LV-D report or sort
>>                 through your LV-E report to see what value eQUEST has calculated.
>>                  Compare these values to the ASHRAE Fundamentals results for overall
>>                 assembly values including frame to see how close you've come.  I would
>>                 not blindly trust that eQUEST will give you an appropriate overall
>>                 assembly value based on entering only the center of glass number.
>>
>>                 However, if this is for a LEED study, this is not adequate.  This an
>>                 excerpt from an e-mail I sent out recently regarding LEED and NFRC
>>                 requirements.
>>
>>                 In order to meet LEED EAp2 Minimum Energy Performance, the project must
>>                 comply with all mandatory provisions of ASHRAE 90.1-2007.  Section
>>                 5.4.2 Fenestration and Doors requires that fenestration performance be
>>                 determined per section 5.8.2.  Section 5.8.2.4 U-factor requires that
>>                 the U-factor for the overall fenestration area (including framing) be
>>                 determined in accordance with NFRC 100. If you do not have NFRC data
>>                 available, values from section A8.2 are the only acceptable alternative.
>>
>>                 Robby Oylear, LEED®AP BD+C
>>                 Mechanical Project Engineer
>>                 Energy Analyst
>>                 D206-788-4571 |C206-354-2721
>>
>>                 www.rushingco.com <http://www.rushingco.com/>
>>
>>
>>
>>
>>
>>                 On Wed, Jul 27, 2011 at 8:14 AM, Omar Katanani <omar at ecoconsulting.net
>>                 <mailto:omar at ecoconsulting.net>> wrote:
>>
>>                 Dear all,
>>
>>                 I have a small question regarding entering
>>                 window properties to eQUEST:
>>
>>                 I have read a lot of emails in the forum
>>                 discussing NFRC testing, LBNL Window 5 import, and other topics that I
>>                 haven?t
>>                 paid attention to before.
>>
>>                 The way I modelled my windows is the
>>                 following:
>>
>>
>>                            1. I have manufacturer?s specifications listing the glass
>>                     U-values, not the total assembly.
>>                            2. In the ?Glass Types? (eQUEST Detailed Mode), I created
>>                     glass types, and entered the glass conductance, visible
>>                     transmittance, SC, and emissivity from the manufacturer?s details I
>>                     have.
>>                            3. When creating windows, I specify which glass type (from
>>                     the ones I created in step 2), in addition to the frame width and
>>                     conductance.
>>
>>
>>                     I?m assuming that, given that I
>>
>>                 entered the u-values for the glass only, and then I entered information
>>                 about
>>                 the frame, then I need not worry about any conversions in U-values, since
>>                 eQUEST has all the necessary information to calculate the equivalent
>>                 u-value of
>>                 the whole pane + frame assembly, right?
>>
>>                 I appreciate your feedback / comments
>>                 today if possible, as this has become really urgent!
>>
>>
>>                     Many thanks,
>>                     Omar
>>                     ___________________________
>>                     Omar Katanani
>>                     Sustainable Design Engineer
>>                     Email: omar at ecoconsulting.net <mailto:omar at ecoconsulting.net>
>>
>>                     EcoConsulting (Lebanon)
>>                     NahasBuilding, 4th floor
>>
>>                     4 St-Maron Street/ Georges Haddad Avenue
>>                     Postal Code: 2028 5806
>>
>>                 SAIFI
>>                 Beirut, Lebanon
>>                 Tel: +961 (0) 1 971 266
>>                 Mobile: +961 (0) 3 045 045
>>
>>                 EcoConsulting (UK) Ltd
>>                 28 Marshalsea Road
>>                 London, SE1 1HF
>>                 Tel: +44 (0) 207 939 0989
>>                 Fax: +44 (0) 207 939 0981
>>                 Website: www.ecoconsulting.net <http://www.ecoconsulting.net/>
>>
>>
>>
>>                 _______________________________________________
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>>
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>>
>>
>>
>>         -- 
>>         Carol Gardner PE
>>
>>
>>
>>         -- 
>>         Carol Gardner PE
>>
>>         This email and any files transmitted with it are confidential and intended
>>         solely for the addressee. If you are not the named addressee you should not
>>         disseminate, distribute, copy, or alter this email.
>>
>>         _______________________________________________
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>>
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