Got my posts deleted on another forum

Felixbiel · October 3, 2011

This is exactly what I was looking for, to have a conversation back and forth with Tritek, Just like yall are doing right now. Instead I got jumped. I must have touched a nerve.

You are talking tint issues on a car forum. Not a lot of people care to discuss the engineering behind window films on a car forum.

I am just talking about the way the discussion is going down. Not what the actual discussion is.

The ///Man · October 3, 2011

This is exactly what I was looking for, to have a conversation back and forth with Tritek, Just like yall are doing right now. Instead I got jumped. I must have touched a nerve.

You are talking tint issues on a car forum. Not a lot of people care to discuss the engineering behind window films on a car forum.

I am just talking about the way the discussion is going down. Not what the actual discussion is.

I'm on a lot of car forums, seems pretty typical. Hell, some forums I'm on they would be sending you pizza right about now, and lots of it.

Fiveofeen · October 3, 2011

Its a forum, unless you have a post count you must be on your best behavior and even then expect an argument. Bad ones are like debate club without any rules, reason or logic.

Makes you like this place a lot more huh?

EWF · October 4, 2011

I'm sure you have contacts in Asia, why do they choose to measure low intensity IR wavelengths and not the high intensity ones?

Hi Vq,

The Asians are not alone in this respect. JWF quotes 1075. 3M quotes in this range as well.

In their defense, there is a logical reason. As you climb above 1100, you encounter multiple/significant gaps (as outlined in my earlier post) where the IR actually drops to 0%. Above 1900, it falls exponentially. In other words, the bulk of the IR that reaches the earth's surface is in this range. While not complete, it does represent the majority.

I have several graphs that depict this. I will try to find a very good one to post tomorrow (workload permitting).

Just to reiterate, we both generally agree that when SC/SHGC data is available, IR should be reclassified as "nice to know" but non-essential.

-Howard

EWF · October 4, 2011

In your example of using an EDTM meter, is this entirely accurate? I see ambiguity here as well.

Hi Vq,

Those EDTM meters have been a staple of the glazing industry for decades. The folks at EDTM stand behind them and insist that they correlate well with the more expensive lab units.

For the sake of our discussion, let us propose that the unit is "slightly off". We can still make an educated decision on Film A vs Film B by putting the meter into Percentage Mode (P-Mode). Any errors or limitations that are present would equally impact all the specimens you were comparing.

If I were making sales presentations to clients, I would make good use of the meters. I would tell that homeowner to request that all the salespeople visiting their home or office install a small piece of film onto one of their sunlit windows. I would then install my film right next to the others, put the meter in P-Mode and then hand it over to the customer to take the readings. In general, the film with the greatest needle deflection will win.

What a surprise when the film that causes the greatest needle deflection or percentage drop is very often the film that costs the least amount of money !!!!!

-Howard

Edit = Typo (it's late here - I am tired).

vquestfilms.com · October 4, 2011

I'm sure you have contacts in Asia, why do they choose to measure low intensity IR wavelengths and not the high intensity ones?

Hi Vq,

The Asians are not alone in this respect. JWF quotes 1075. 3M quotes in this range as well.

In their defense, there is a logical reason. As you climb above 1100, you encounter multiple/significant gaps (as outlined in my earlier post) where the IR actually drops to 0%. Above 1900, it falls exponentially. In other words, the bulk of the IR that reaches the earth's surface is in this range. While not complete, it does represent the majority.

I have several graphs that depict this. I will try to find a very good one to post tomorrow (workload permitting).

Just to reiterate, we both generally agree that when SC/SHGC data is available, IR should be reclassified as "nice to know" but non-essential.

-Howard

Howard,

Thanks for the graph offer, I am a LBNL Optics user so I can actually build a point by point model of solar transmission at every wavelength point in excel. What I've seen with most of those graphs is they are misleading in terms of the true scope of the Solar spectrum. The range from 300nm to 1100nm (a total of 800nm) is widened and from 1100 to 2500 (a much larger total of 1400nm) is narrowed and squashed to accommodate the larger portion of the spectrum. I don't think that is an accurate representation.

As for the Asian measurements, everyone seems to conveniently skip over 780-900nm the most intense energy in the NIR spectrum. I can see skipping the "dead spots" but why skip the "hot spots?" It makes no sense except to take the regions that put a given film at Asia competitive IR readings of 91%-99%. That is what sells over there.

This is probably the most I have ever talked about IR, it is irrelevant to energy modeling so I don't waste a lot of time on it. Simple convincing argument is that all energy modeling software does not have an input field for "IR." Tvis, U Factor, and SHGC are the three data entry fields for fenestration. End of discussion right there. :lol

vquestfilms.com · October 4, 2011

In your example of using an EDTM meter, is this entirely accurate? I see ambiguity here as well.

Hi Vq,

Those EDTM meters have been a staple of the glazing industry for decades. The folks at EDTM stand behind them and insist that they correlate well with the more expensive lab units.

For the sake of our discussion, let us propose that the unit is "slightly off". We can still make an educated decision on Film A vs Film B by putting the meter into Percentage Mode (P-Mode). Any errors or limitations that are present would equally impact all the specimens you were comparing.

If I were making sales presentations to clients, I would make good use of the meters. I would tell that homeowner to request that all the salespeople visiting their home or office install a small piece of film onto one of their sunlit windows. I would then install my film right next to the others, put the meter in P-Mode and then hand it over to the customer to take the readings. In general, the film with the greatest needle deflection will win.

What a surprise when the film that causes the greatest needle deflection or percentage drop is very often the film that costs the least amount of money !!!!!

-Howard

Edit = Typo (it's late here - I am tired).

Hi Howard,

We are an EDTM distributor, they make some of the finest hand held portable instruments for the film and glazing industries and they have been a great partner to us. I am very familiar with their capabilities and on the sales and glass inspection side there is a place for these fine tools. As with all things they do have their limitations. I highly recommend using EDTM meters to inspect glass units for thickness, pane count, coatings, coated surface #, laminates, and tempering. Glass inspection meters are just about mandatory for FG these days.

For sales presentations there are some excellent EDTM meters for measuring smaller regions of the solar spectrum for UV transmission, VLT, some IR at specific wavelengths, and solar transmission % at limited wavelengths. These meters are great for those types of demonstrations but they cannot used to accurately determine SHGC on filmed glass for instance. The silicone cells have limits as to what wavelengths they can measure, the highest affordable meter we sell only goes to 1300nm. So back to what I was saying above in regards to your EDTM comment earlier is that there is no way one of these instruments can measure the entire NIR spectrum as accurately as a $100k spectrophotometer. We use the latter for determining transmittance measurements for everything in the solar spectrum (UV, Tvis, IR) to calculate the total energy measurements like SHGC. I'm sure EWF or your MFG's sends your products to a labs that uses the same equipment to calculate your measurements. In the supply arena we have to use the expensive stuff to get the accurate numbers. NFRC requires it.

Hey, save your "needled" meters as everything is digital nowadays. If you find an old needle meter that still works take good care of it because you won't be able to get a new one very easily. :lol

Felixbiel · October 4, 2011

I got gang raped over there. Oh well you live you learn you buy some lube

October 4, 2011

yup you did :waving

EWF · October 4, 2011

These meters are great for those types of demonstrations but they cannot used to accurately determine SHGC on filmed glass for instance. The silicone cells have limits as to what wavelengths they can measure, the highest affordable meter we sell only goes to 1300nm.

Hi Vq,

Agreed. Even the meter companies (EDTM) acknowledge that you can "approximate" SHGC. But determining SHGC is not the objective. The idea is to compare the in-field performance of Films A,B,C. Minor limitations in the meter would apply equally to all the films you meter with it - so no single film would significantly benefit.

I found the graphic (below) that shows the level of radiation across the spectrum that reaches the earth's surface. The meter you refer to (which tops out at 1300) is very useful as the IR declines steeply above that. This means that such a meter can do a terrific job of detecting close to 90% of the relevant spectra and this information can be used to make a sound and informed decision on Film A vs. Film B. Even the data published by the manufacturers (and included in the NFRC database) are subject to long disclaimers which basically say that there is no guarantee that any particular roll of film will meet the published spec. As there is no "perfection", "pretty dam close" works just fine.

The graphic follows. As you can see, there is comparatively little radiation above the 1300. - Howard

Note on this graphic, in case it is not clear:

The yellow area is the radiation level at the upper limit of the earth's atmosphere
The red areas are the radiation levels at the surface (where we install film)
5250C Blackbody = (the sun)

Edit = Typo