| 1. | Re: homeowner-made interior storm windows
Posted by RayMcGowan on 9/9/2010 1:59:21 PM
NFRC cannot make a final decision on the federal tax credit qualifications. You may want to talk to Frost King/Thermwell product to see if they will qualify. |
| 2. | Re: NFRC 100 and ASHRAE 90.1-2004
Posted by RayMcGowan on 9/2/2010 8:43:12 AM
ASHRAE 90.1-04 requires that the U-factor be calculated by NFRC 100 and the SHGC be calculated by NFRC 200. NFRC 100 and 200 are instruction for simulation software to make these calculations. ASHRAE 90.1 also requires the U-factor and SHGC to be calculated by a lab accredited by an accreditation body such as NFRC. here is a list of accredited NFRC simulation labs: http://www.nfrc.org/simulationlabs.aspx |
| 3. | Re: NFRC 100 and ASHRAE 90.1-2004
Posted by raymcgowan on 10/23/2009 10:22:44 AM
NFRC always encourages full NFRC certification for NFRC ratings. Full certification means the code offical will have a third party to confirm the ratings. ASHRAE 90.1 requires NFRC 100 AND 200 be used to determine U-factor, SHGC, and VT. these docuemnts imply using the simulation software. ASHRAE requires the use of an accredited lab such as NFRC accredited lab to do the simlations. please use our web site to locate an accredited lab. YOu are correct, i cannot interpret ASHRAE as an NFRC ... |
| 4. | Re: NFRC 100 and ASHRAE 90.1-2004
Posted by RayMcGowan on 3/25/2009 12:09:03 PM
Dear SIBDLEED,
Please email me direclty at rmcgowan@nfrc.org for a detailed explanation. NFRC is frequently getting this quetion based on LEED requirments. |
| 5. | Re: Visible Light Transmittance of old windows
Posted by RayMcGowan on 8/24/2010 9:10:00 AM
single pane, clear glass has a VT of 0.76 (per ASHRAE 90.1-07) |
| 6. | Re: U-Value Threshold and Double Pane, Argon Filled Req't to meet U= .30
Posted by RayMcGowan on 8/24/2010 9:08:25 AM
NFRC ratings eliminate the need to do the above calculation. The online NFRC database has 2.5 million rated products and is searchable on U-factor and SHGC. simply enter the desired values and select window products. |
| 7. | Re: Visible Light Transmittance vs. Solar Heat Gain for different elevations
Posted by RayMcGowan on 8/24/2010 9:05:22 AM
NFRC recommends purchasing ENERGY STAR qualified windows to maximize energy savings and minimize summer heat gains and winter heat loss. |
| 8. | Re: Visible transmittance of single-pane glass
Posted by raymcgowan on 6/30/2010 4:09:33 PM
Clear glass is about 0.84 for VT. |
| 9. | Re: NFRC Gold Label
Posted by raymcgowan on 11/2/2009 12:37:21 PM
NAMI=National Accreditation and Management Institute. This is the NFRC accredited inspection agency for this NFRC participating window manufacturer.
NFRC 100/200=These are the two NFRC standards that the energy ratings are derived from.
PAT=MW Patriot of Rocky Mount, VA. They are an inactive NFRC participant.
rating: NFRC=this manufacturer rated using NFRC methods
series: 1700/1800/1900 SH= the manufacterers single hung ... |
| 10. | Re: NFRC Gold Label
Posted by raymcgowan on 4/8/2010 3:32:37 PM
Dear Arnold,
This is Diamond Window of Boston: 617 282-1688 |
| 11. | Re: 80 & 90% solar window screens
Posted by raymcgowan on 1/15/2010 11:35:55 AM
Please refer to the IRS or to ENERGY STAR to determine tax credit qualification. I suggest this site for more information: http://www.energystar.gov/index.cfm?c=tax_credits.tx_index
NFRC does not determine tax credit qualifcations. |
| 12. | Re: Nominal Glass Thickness
Posted by raymcgowan on 12/15/2009 3:55:46 PM
Dear Mr. Van,
here is a brief explanation from the simulation manual for nominal thickness: "The nominal thickness feature, turned on by checking the “Use nominal glass thickness” when importing a glazing system, can be useful for multiple glazing options, where THERM expects all the glazing system
options to have identical thicknesses. This feature is explained in more detail in the THERM User’s Manual."
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| 13. | Re: Adding films to insulated windows
Posted by raymcgowan on 9/4/2009 8:29:05 AM
I assume you are asking about window manufacturers? If so, I cannot speak for them. You are a real estate inspector. What are you inspecting for? Window energy performance? If so, NFRC rates aftermarket window films. Please ask the window film supplier to provide the NFRC ratings for the film. You will then know the improved energy performance resulting from the film. |
| 14. | Re: U Factor Equation
Posted by raymcgowan on 10/23/2009 11:37:00 AM
NFRC 100 refers to ISO15099, seciton 4.1.3, equation 9. It is an area weighted sum of the U-factors of the edge of glass, center of glass, frame, divider, and divider edge area. Please refer to ISO 15099 for futher information.
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| 15. | Re: U-factor / heat loss effects of windspeed
Posted by raymcgowan on 8/25/2009 11:57:51 AM
Yes, NFRC U-factors use a 15 mph exterior windspeed assumtion.
Currently, NFRC does not have a u-factor rating for window films. NFRC may consider that rating in the future. |
| 16. | Re: Energy efficiency airspace graph
Posted by RayMcGowan on 6/10/2009 2:39:15 PM
Please refer to 09 ASHRAE fundamentals, chapter 15, page 15.4. the graphs are there. |
| 17. | Re: Energy efficiency airspace graph
Posted by RayMcGowan on 7/1/2009 2:28:46 PM
Figure 3 in the current ASHRAE Fundamentals Fenestration Chapter will give you the answers. i cannot pass it along in this forum. |
| 18. | Re: U factor ratings
Posted by RayMcGowan on 4/13/2009 3:45:13 PM
Dear SAM,
I agree that 0.25 or so is fantastic for aluminum. I encourage you to ask your source if that is an NFRC rating number. You may also use our online certified products directory to confirm the ratings.
You are correct that the NFRC u-factor, SHGC, and VT are calculated for the entire product including frame, sash, etc. |
| 19. | Re: possible wind damage to dual pane glass
Posted by RayMcGowan on 3/30/2009 8:19:39 AM
NFRC cannot comment on this matter. I suggest an independent third party be sought. |
| 20. | Re: possible wind damage to dual pane glass
Posted by RayMcGowan on 3/31/2009 11:08:11 AM
sorry, NFRC does not have a recommended contact. |
| 21. | Re: Existing Windows Analysis
Posted by raymcgowan on 9/22/2008 7:34:22 AM
Dear Mr. Kennedy,
I recommned using the ASHRAE Fundamentals Handbook, the Fenestration chapter. It will list numerous estimations of performance for a wide variety of window component combinations.
You may also consider the default tables in either ASHRAE 90.1 or IECC. they will indicate worst case scenarios. the ASHRAE fundamental handbook will give a closer estimate.
it is unlikely the etching on the window will have any chance at ... |
| 22. | Re: Custom glazing
Posted by raymcgowan on 7/31/2008 9:38:06 AM
Dear Mr. Griessen,
if i understand correctly, you will improve your existing window then search for similar windows to see what the rating might be? if so, i doubt you will find anything with low-e paint. the default wood framed, double pane value from the IECC codes is U-factor= 0.55. this is about the best estimate i can provide.
please call me @ 240-821-9510 with questions. |
| 23. | Re: Custom glazing
Posted by raymcgowan on 3/14/2007 10:47:08 AM
Dear Mr. Lubliner,
you would have to submit this for rating at an NFRC accredited simulator for an actual rating. if you are interested in doing so, please call me, Ray McGowan @ 301-589-1776, 210.
A simple way to rate it would be to use the IECC default tables. That rating would be U-factor = 0.55. (wood frame, double glazed). |
| 24. | Re: Air Infiltration vs. Air Leakage
Posted by raymcgowan on 3/10/2008 7:38:54 AM
Air leakage is the more common term for air passing through a fenestration product. Air infiltration is usually associated with an entire building.
NFRC 400 is our air leakage test procedure that is largely ASTM E283 based. this rating is optional and rarely used by the industry. AAMA/WDMA 101 is the more common standard for air leakage. that test is simply pass fail so no rating appears on the label.
in 2007 NFRC did < 100 air leakage tests. that is ... |
| 25. | Re: glass color in historic buildings
Posted by raymcgowan on 10/22/2007 9:44:45 AM
Dear Sir/Madam,
NFRC rates window energy performance only. NFRC ratings do not report color or visible reflection.
NFRC ratings do include U-factor (winter heat transmission value) and SHGC (solar heat gain coefficient, summer heat gain potential). These ratings will answer part of your question. NFRC recommends using window that meet the ENERGY STAR requiremnts for your location. please click on www.energystar.gov to select energy efficient windows.
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