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14 Responses to “Contact Us”


  1. 1 chris August 29, 2008 at 3:22 pm

    if alow e window has a .28% shgc how will prestige film compete with that is prestige 70 or 60 at .18% on a 70 to 90 degree angle

  2. 2 windowfilmonline August 29, 2008 at 4:35 pm

    Low E or “low emissivity” is glass that has been coated to reflect far infra-red back into a room. This affects the U Value of a window and not the SHGC unless your widow has coatings on surface #2 & #3. A SHGC of .28 leads me to believe that is probably the case. Your window is performing very well so Prestige 60 or 70 is not going to give it significant solar energy rejection. The only benefit you may get is increased UV rejection. A less expensive window film can do that just as well.

    Sun Angle is more of a marketing ploy than anything else. See vc’s blog on this subject.

    -WFO

  3. 3 Deep August 30, 2008 at 3:00 pm

    I have read your blog with great interest, and I find the articles both informative and extremely helpful. What I am wondering is what relationship the authors have to this site? I notice that you seem to push using films that are NFRC rated for the most part. (Just wondering whose payroll you are on, thats all…lol)

    Deep

  4. 4 windowfilmonline September 4, 2008 at 12:37 pm

    Thanks for the comment Deep!

    I believe the “about” page explains it all. No one around here is on anybody’s payroll. You may want to re-read some of vc’s blogs because I see him “pushing” the window film industry as a whole to get all films NFRC Certified more so than any particular film brand. I find his reasoning hard to argue with.

    -WFO

  5. 5 Joseph Richard September 5, 2008 at 11:57 am

    As the editor of CPFilms’ Technical Updates newsletter, and author of the article on infrared transmission in Issue 10, I want to thank you for your interest and enthusiasm for the work we do in technical services here at CPFilms. On Monday, September 8, Issue #11 will be published containing a follow-up article of equal and far-reaching importance. Fasten your mental seat belt–it should be quite a ride, and altogether “illuminating.”

  6. 6 vclimber September 5, 2008 at 1:53 pm

    Nice article Joseph, I kinda of figured there would need to be a follow-up to “illuminate” us all. More facts need to transfer inward so that window film professionals can warm up to new thinking. Thanks for visiting, we’re looking forward to the next issue. Have a great weekend!

  7. 7 vclimber September 10, 2008 at 5:10 pm

    Joseph,

    Well, it was two days late but well worth the wait. 🙂 Issue #11 contains
    a fascinating article to say the least, it definitely deserves some press from this blog site as it concerns the reputation of our industry. I also see some serious questions that will arise from the information published in light of new industry achievements. Perhaps, another follow up to this subject?

    Thanks for all of your hard work.

    -vc

  8. 8 Thaddeus January 2, 2009 at 9:46 pm

    Dear Joseph,

    I have great interest in your blog as it’s very informative. Recently, i got a solar film for my room to try out first before applying it to my house. I wonder if this specification of the film i use is good to cool down my room.

    I notice that the film i got is too dark.

    Kindly advice.

    Visible Light Transmittance (VLT) : 6%
    Solar Energy Transmittance (SET) : 7%
    Solar Energy Absorbence (SEA) : 45%
    Solar Energy Reflectance (SER) : 48%
    Total Solar Energy Rejected (TSER) : 83%
    Ultra-Violet Rejected (UVR) : 99%
    Thickness : 1.5 mil

    • 9 windowfilmonline January 6, 2009 at 11:45 pm

      Thaddeus,

      Thank you for your kind words. Vclimber always says that window film does not cool rooms, air conditioners cool rooms. Technically speaking, he is correct. The film you are using will reject 83% of the total solar energy which will reduce the “heat gain” thus making it more comfortable and reducing the load that is placed on your air conditioner. The film that you purchased is very dark and it is also very reflective which is why it performs so well. Professional window film companies carry a variety of films that are much lighter and in many cases far less reflective. A well-trained professional can help you find the right balance between visible light transmittance, film reflectivity, and total solar energy rejection. Many companies offer free estimates as well as comprehensive warranties. You might want to check into this.

      Take care,

      -WFO

  9. 10 David February 8, 2010 at 9:20 am

    First off, great blog. I’m in the market for solar films and I’ve learned a lot from this site.

    I have a basic question about solar film infrared rejection that, frankly, I can’t seem to find answered anywhere. Do solar films only reject infrared one-way? I’m looking at a few ceramic and spectrally selective films (Vista, 3M, V-Kool)in order to keep my apartment cool in the summer and they all have decent SHGC and reject most infrared. But do they also keep infrared inside during the winter? And if not, why not?

    Thanks for your help,

    David

    • 11 windowfilmonline February 8, 2010 at 2:01 pm

      Solar films can absorb or reflect IR in either direction but it depends on the type of film and the wavelength of IR that you are trying to filter.

      Most films will filter various percentages of incoming “near-infrared” radiation which will contribute to the reduction of solar heat gain. They will also have what is called a “U value” which is basically a measurement that tells you how much heat (long-wave IR) is being reflected back into the building. Most films do not have the greatest U vales but there are some that are designed with better. These are called “low Emissivity” films. They are designed to reflect the “long wave IR” which we feel as heat back into the interior. Vista has a few of these films, 3M might still have such a product, but V-Kool does not.

      The down side to “low E” films is that they are tremendously reflective to the interior which will turn your window into a mirror at night. And what’s more concerning is that they do not have a very long warranty life. 7yrs is the best I know of…

      The ceramic films will probably offer you the best balance between incoming heat rejection and interior heat retention plus they look really nice, have great optics, and the a much longer warranty. Hope this helps, thanks for reading our blog.

      • 12 David February 8, 2010 at 2:34 pm

        Thank you. Very helpful.

        I’m still not 100% clear as to the technical reason why so many of these films bounce back most of the exterior IR but not interior IR (low-e films excluded, of course). Is it because the type of IR is different? I get the impression from your comment that the average wavelength of IR from outside tends to be shorter than what is emitted from indoors. So, if true, is it that the films are better at blocking the shorter wavelegth IR?

        Thanks again.

      • 13 windowfilmonline February 9, 2010 at 11:04 pm

        Yes, that is correct.

        IR is categorized into short wave 780-2500nm and long wave 2501-200,000nm. Shorter wavelength IR (NIR) transmits from the sun and we don’t feel it until it is absorbed by an object and re-radiated as long wave IR (FIR). We can feel the heat from longer wavelengths but not the short ones.

        Solar control window films are designed to filter incoming short wavelengths resulting in reduced heat gain because there is less NIR transmitting through the glass and being absorbed & re-radiated by interior objects such as furniture. There are numerous materials that can filter the incoming NIR but the longer FIR wavelengths are only reflected effectively by certain materials. Thus the need for “low E” films coated with materials specially designed to reflect FIR wavelengths (heat) back indoors. So your heater generates FIR (heat) and those wavelengths are reflected by the “low E” coating reducing the emissivity or energy transfer through the glass from interior to exterior.

  10. 14 David February 10, 2010 at 6:05 am

    Thank you. That explanation is exactly what I was looking for.


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