Forum discussion
NC-2009 EAp2: Minimum Energy Performance
For the proposed model, can we refer to table A8.2 for U-factor of the window but refer SHGC and VLT to the manufacturing data (tested based with NFRC standard)? In table A8.2, U-factor, SHGC, and VLT are provided for unlabeled glass. However, we would like to refer only U-factor since the on-site customized frame are complicated.
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Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
November 6, 2016 - 6:38 pm
I think you could as it sounds conservative. The U-values in A8.2 are likely much higher than your windows will be. Make sure to explain your rational to the reviewer.
Jatuwat Varodompun
DrGreen Building Soultion
26 thumbs up
November 7, 2016 - 10:32 am
Thanks Marcus
I am not quite know the NFRC standard. After I read it, it sound like both NFRC 100 and NFRC 200 will have the standard frame material (ie non-residential aluminum) and size that could be used in the simulation process. if that is the case, the spec sheet that indicated the U-factor is conformed with NFRC 100 and SHGC is conformed with NFRC 200 should be used, isn't it?
At first, it is hard to include the frame in the process, since each frame on-site of each window is different in size but it seems that the NFRC 100 and 200 is simpler than I thought (if default frame with standard size can be used). Am I correct?
Thanks
Jatuwat Varodompun
DrGreen Building Soultion
26 thumbs up
November 7, 2016 - 10:33 am
Thanks Marcus
I am not quite know the NFRC standard. After I read it, it sound like both NFRC 100 and NFRC 200 will have the standard frame material (ie non-residential aluminum) and size that could be used in the simulation process. if that is the case, the spec sheet that indicated the U-factor is conformed with NFRC 100 and SHGC is conformed with NFRC 200 should be used, isn't it?
At first, it is hard to include the frame in the process, since each frame on-site of each window is different in size but it seems that the NFRC 100 and 200 is simpler than I thought (if default frame with standard size can be used). Am I correct?
Thanks
Jatuwat Varodompun
DrGreen Building Soultion
26 thumbs up
November 7, 2016 - 10:42 am
I am not familiar with NFRC standards. However, after I read them, it seems that both NFRC 100 and 200 will refer to the standard frame size and material such as non-residential aluminum to simulate both U-factor and SHGC. if that is the case, the spec from the manufacturer that indicates both NFRC 100 and NFRC 200 should satisfy the credit requirement. Am I right?
At first, I though that if you have to include the actual frame size for each window. it would complicate the model a lot because each window would have different U-factor and SHGC. but it would not be the case if NFRC 100 and 200 refer to standard frame size and reference material. Is my assumption correct?
Thanks
Jatuwat Varodompun
DrGreen Building Soultion
26 thumbs up
November 7, 2016 - 10:44 am
I am not familiar with NFRC standards. However, after I read them, it seems that both NFRC 100 and 200 will refer to the standard frame size and material such as non-residential aluminum to simulate both U-factor and SHGC. if that is the case, the spec from the manufacturer that indicates both NFRC 100 and NFRC 200 should satisfy the credit requirement. Am I right?
At first, I though that if you have to include the actual frame size for each window. it would complicate the model a lot because each window would have different U-factor and SHGC. but it would not be the case if NFRC 100 and 200 refer to standard frame size and reference material. Is my assumption correct?
Thanks
Jatuwat Varodompun
DrGreen Building Soultion
26 thumbs up
November 7, 2016 - 10:47 am
I am not familiar with NFRC standards. However, after I read them, it seems that both NFRC 100 and 200 will refer to the standard frame size and material such as non-residential aluminum to simulate both U-factor and SHGC. if that is the case, the spec from the manufacturer that indicates both NFRC 100 and NFRC 200 should satisfy the credit requirement. Am I right?
At first, I though that if you have to include the actual frame size for each window. it would complicate the model a lot because each window would have different U-factor and SHGC. but it would not be the case if NFRC 100 and 200 refer to standard frame size and reference material. Is my assumption correct?
Thanks
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5907 thumbs up
November 7, 2016 - 10:50 am
NFRC is a testing procedure that US window manufacturers use to certify the performance of specific window products. It can't really be used outside that. If the window manufacturer has this information then you can use it.
If there are large variations in window size you should develop a methodology for more accurately modeling the windows rather than just model the NFRC value the same for each. So which method you use to model the windows will vary depending on the situation. You can always model the frames separate from the glazing and just use the NFRC values as a test that your model is accounting for the frames accurately.