EXPRESS FILMS EXPERT QUIZ #1 - OCTOBER 2011

[vquestfilms.com]

Vq,

Thanks for checking into that. I am rather impressed that you actually have that software at your fingertips.

I am not able to post anything further today. I will catch you tomorrow.

I enjoyed our debate. I learned much from it thanks to you and I look forward to meeting you at SEMA.

-Howrad

Thanks Howard. We do know a little, its part of that whole value thing I was talking about.

I enjoyed our discussion, I learned quite a bit about you as well. I look forward to meeting you.

-Btw I've got measurements from 300-2500nm

[Guest VOLTRON]

The only way a I can see a BTU meter being benificial to 1 film in a film vs film comparison is if one of those films block out more of the heat in that particular range of nm then the other. Like in the IR lamp demos that show IR rejection showing that whoevers IR film blocks more heat then whoevers standard film that has better TSER then the IR film. A good test would be to get a couple ice cubes and some paper plates and put them in the grass on the paper plates out in the sun and then hold film above the cubes at equal distances and see which cube melts faster! Now thats scientific!

[Guest tinthoss]

Who's on first

I don't know but I would say vquest is batting cleanup and just hit a grand slam!

[TomTint]

While all this info is a great read, it outlines a real problem. When our industry can not figure out how, when,where and what to measure to determine true values. Mfrs testing and reporting criteria that is not worth the paper it is printed on. And while 3rd party testing is a step in the right direction, I think it still needs to be more transparent and comprehensive.

[vquestfilms.com]

Modeling is best Tom and quite accurate. Seriously, we can match just about any glass type and include the frame which is real world conditions. Heck, I can even give you SHGC "on angle."

-edit spelling...

[EWF]

The only way a I can see a BTU meter being benificial to 1 film in a film vs film comparison is if one of those films block out more of the heat in that particular range of nm then the other. Like in the IR lamp demos that show IR rejection showing that whoevers IR film blocks more heat then whoevers standard film that has better TSER then the IR film. A good test would be to get a couple ice cubes and some paper plates and put them in the grass on the paper plates out in the sun and then hold film above the cubes at equal distances and see which cube melts faster! Now thats scientific!

Hi Voltron,

I agree with you and I like your proposed method. If you read Post #50, you will see that I eluded to a similar alternative via the use of a non-contact thermometer.

Rest assured, however, that if certain manufacturers did not fare well in such a test, you would hear them complaining that it does not fairly represent their performance because water reflects such and such wavelength and absorbs such and such other wavelength differently and that their film can not be fairly assessed using such a method.

-Howard

[EWF]

While all this info is a great read, it outlines a real problem. When our industry can not figure out how, when,where and what to measure to determine true values. Mfrs testing and reporting criteria that is not worth the paper it is printed on. And while 3rd party testing is a step in the right direction, I think it still needs to be more transparent and comprehensive.

Well said TT. It really is too bad.

This is why I am such a proponent of in-the-field direct measurements. If I want to know how hot a kettle of water is, I can just stick my lab quality $99 thermometer in it and get a reading +/- 0.2%.

EDTM is a decades old reputable company that makes metering equipment which is used to make sales presentations in the glazing industry. But this thread has raised doubts as to the accuracy, reliability and applicability of the equipment.

I accept the fact that LBNL/NFRC is the well qualified third party arbiter of window film/glazing performance. But they have absolutely no control over the "roll-to-roll" variances which all manufactures acknowledge. They refer to "normal manufacturing tolerances" and "within industry standards". I have never seen, read, or heard of a set of guidelines that address how far out of spec a roll is allowed to be before it is considered unacceptable, defective, etc.

Neither the NFRC nor the manufacturer will guarantee how far in/out of tolerance the roll is which you are about to apply to the glass. You don't have to look very far to read threads on these boards of films which have 6-9% variances from the published VLT printed on the box and in the manufacturer data tables.

Serendipitously, I had a customer walk up to our Danbury customer counter yesterday with a roll of competing (NFRC rated manufactuer's) film which he claimed was off by 8%. It came from a very reputable and respected manufacturer and I have to admit that I was initially skeptical of his claim. At his request, we metered it ourselves. Sure enough, this guy was exactly right - the VLT was off by 8% from what was published. An 8% swing in VLT would translate to a very significant difference in the SHGC. I assured him that the manufacturer would surely offer to replace it without protest, but he felt that was not the point.

-Howard

[EWF]

No, you are missing a couple of important factors.

1. You are still not measuring the entire solar spectrum up too 2500nm. By measuring 300-1100nm you are only covering about 50% no matter what the intensity is.
   
2. And of that 50% that you are measuring, the crystalline silicone cell in your meter can only measure up too about .09 W/m2/nm which leaves the rest of the energy >.09 to 1.4 W/m2/nm as unmeasurable. So you are missing a good chunk of energy in the 400-750nm range.
   

Your method is selective and limited... still not very accurate.

Hello Vq,

We are at an impasse.

Notwithstanding all of the certifications, data tables, simulations, test guidelines, variances, etc, EWF films do as well or better than competing films when tested on the glass, in the field with a BTU meter. Your response? The meter and the test method is not precise enough to make a determination.

I openly admit that I am not an expert on precisely how well suited these meters are for this purpose. My opinions are based solely upon discussions that I have had directly with EDTM. I provided them with a complete description of my field testing methodology. All of my questions were answered to my satisfaction.

This is what has to happen next:

EDTM is going to have to weigh in here (on this thread) or start their own thread or give me a written explanation that I can post. You are implying that their equipment is not fit for the ordinary purpose for which it is intended (comparing film vs. film) You are a very knowledgeable, experienced and seasoned professional, Vq. I admit, you might be right on this, but EDTM needs to have their fair hearing first.

-Howard

[vquestfilms.com]

Howard,

I am thoroughly confused where you are going. Below is one of your first posts and you seem to be in favor of SHGC, SC, and NFRC methodology. Now your have spun full circle and now you are saying that using a BTU meter and a non-contact thermometer is the way to determine film performance.

Hi Vq,

I don't believe there is one. Most of the major lines (Llumar, Vista, Panorama, Solar-Gard, Madico, Hanita) are now following IWFA and NFRC guidelines and have stopped reporting it, in favor of SHGC/SC. The major holdouts are 3M & Huper and they show no sign of yielding.

Reference: http://www.filmnow.c...LES/IWFA_IR.pdf

See ya Tuesday !!!

-Howard

I do not know you very well Howard but it is becoming clear to me that you are even going so far as to spin this conversation so that it looks as though you are attempting to pit me against EDTM by implying that I do not think window film professionals should be using their equipment and that cannot be further from the truth.

If you want to bring them into the discussion, that is your call I'm fine with it. But just so you know, I have used facts that have come directly from them and that can be referenced on their website.

So in regards to the original conversation and with all due respect I will say "to each their own." I am going to leave it at that there is no need for me to train my competition any further than I have and I am not going to stand for being misrepresented in front of my supplier. That is a line that does not need to be crossed, I hope you can see that I have been rather respectful of you and your company as well as the products you represent throughout this thread because I do admire your accomplishments in this industry.

If anyone would like to learn more feel free to give me a call, I will be happy to assist you.

Summation of my point of view:

IR marketing = I am not for it but I also believe the reality is that it is not going away.

SHGC = Best total performance measurement to use it is used by ASHRAE, Glass Industry, LBNL, and most energy efficiency professionals. Glass modeling is the best way to determine whole window SHGC if it is not listed in the NFRC products list.

BIM = Recognized way to determine potential kWh reduction, ROI, and is accepted by the DOE and PUC's for energy rebates and tax credits

EDTM = The best quality and most accurate handheld meters on the market. They are a "must have" for glass inspection I cannot emphasize that enough. They work very well and have their place for demonstrating window film's ability to filter energy which can aid in the sales process of window film.

EWF's knowledge of the affect that surface temperature versus total energy transmission has on a building = I think you need to do some more research on which has the greater affect on the demand side of a building.

This has been an enlightening discussion for me and I do enjoy technical discussions that edify the community. Hopefully we have been able to do that here. Howard, thank you and we will see you next week.

[EWF]

Your method is selective and limited... still not very accurate.

My method is to point an EDTM BTU meter at the window.