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

[Brad Robinson]

I know in Canada they specifically mention using Window 5.x to determine the rating. This is contained in the LEED Canada 2009 Supplementary Energy Modelling Guidelines:

"Specialized software packages such as FramePlus or LBNL Window 5.x may be used to calculate
window performance parameters."



________________________________
From: Robby Oylear <robbyoylear at gmail.com>
To: Carol Gardner <cmg750 at gmail.com>
Cc: Omar Katanani <omar at ecoconsulting.net>; Brad Robinson <brad.robinson at yahoo.com>; equest-users at lists.onebuilding.org
Sent: Friday, July 29, 2011 2:52:49 PM
Subject: Re: [Equest-users] URGENT: Window U-values: Total window assembly v/s Glass only


Carol,

We definitely have the energy code on our side up here forcing projects to provide NFRC data.  However, the way I interpret ASHRAE 90.1, the same requirement exists.

ASHRAE 90.1 section 5.8.2.1 and 5.8.2.2 would indicate that U-factor, SHGC, and air lekage rate are to be determined by a laboratory accredited by a nationally recognized certification organization, such as the National Fenestration Rating Council.  If no label is provided, a signed and dated certification (simulation report) should be provided.

This tells me that a simulation in WINDOW by the energy consultant would not be enough to verify glazing properties.

Am I reading this incorrectly?  Are you bypassing these requirements because of the "manufactured fenestration" part?  ASHRAE 90.1 doesn't clearly define the difference between site-built and manufactured.

-Robby


On Fri, Jul 29, 2011 at 11:41 AM, Carol Gardner <cmg750 at gmail.com> wrote:

Robby,
>
>I would agree that NFRC values for the glazing alone would not be good enough. That is why I recommended using Window. 
>
>I have not had the success you have had obtaining an NFRC rating for the window+frame because the buildings I have been working on are using site-built windows. In Washington, and Seattle in particular, you have had John Hogan working on your codes. It's entirely possible that the level of information you have available is greater than what I have seen.
>
>Carol
>
>
>
>On Fri, Jul 29, 2011 at 11:26 AM, Robby Oylear <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
>> 
>>D206-788-4571 |C206-354-2721
>>www.rushingco.com
>>
>>
>>On Fri, Jul 29, 2011 at 11:12 AM, Carol Gardner <cmg750 at gmail.com> wrote:
>>
>>
>>>
>>>
>>>On Thu, Jul 28, 2011 at 5:40 AM, Omar Katanani <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.
>>>
>>> 
>>>>	1. 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?
>>>> 
>>>>	1. 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, andinput 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
>>>> 
>>>>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
>>>> 
>>>> 
>>>>
>>>>________________________________
>>>> 
>>>>From:Robby Oylear [mailto:robbyoylear at gmail.com] 
>>>>Sent: 28 July 2011 00:53
>>>>To: Omar Katanani
>>>>Cc: Brad Robinson; 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
>>>> 
>>>>D206-788-4571 |C206-354-2721
>>>>www.rushingco.com
>>>> 
>>>> 
>>>> 
>>>>On Wed, Jul 27, 2011 at 2:44 PM, <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>:
>>>>
>>>>>
>>>>>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>
>>>>>To: Omar Katanani <omar at ecoconsulting.net>
>>>>>Cc: 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
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>On Wed, Jul 27, 2011 at 8:14 AM, Omar Katanani <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
>>>>>> 
>>>>>>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
>>>>> 
>>>>> 
>>>>> 
>>>>>_______________________________________________
>>>>>Equest-users mailing list
>>>>>http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org
>>>>>To unsubscribe from this mailing list send  a blank message to EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
>>>>>
>>>>>
>>>>>
>>>>>_______________________________________________
>>>>>Equest-users mailing list
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>>>>>To unsubscribe from this mailing list send  a blank message to EQUEST-USERS-UNSUBSCRIBE at ONEBUILDING.ORG
>>>>
>>>>
>>>>_______________________________________________
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>>>> 
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>>>>
>>>>
>>>
>>>
>>>-- 
>>>Carol Gardner PE
>>>
>>
>
>
>-- 
>Carol Gardner PE
>
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