solar control window film

factors causing fading

UV light plays the largest single roll, but hardly tells the whole story. While solar control window film can stop ultraviolet light without much notice, Visible Light and Heat are another matter. Since visible light and heat combine to make half of the problem of fading, even if you block all UV light you would still face massive fade issues with 50% of damage causing radiation still streaming in. Something needs to be done about these additional two factors – and we still are not done yet.

Visible light is a major component of the fading issue, because it is both a negative and a positive. Yes, it causes fading, but the light it provides is essential. You can’t just block out all the light in a home to stop fading, you can only reduce it. The same is true of heat. Solar contol window film can reject a lot of heat but a percentage will still come through – it’s these remnant percentages that make all the difference.

lets take a look at a well-understood solar control film type, a silver reflective 20%

Silver film U values

This film stops 99%UV, 77% Heat, 80% Visible light. Although it is a dark, highly reflective, high heat rejecting energy saving film type it still has a maximum fade reduction potential of only 77%. Why?

Because of the remaining percentages of VLT, Heat and Miscellaneous that add up to
almost one quarter of the problem.

We haven’t dealt with the miscellaneous section yet; these are factors that solar control film is powerless to address, such as chemicals, smoke, internal lighting (yes those fluorescent lights pump out UV too) and the actual quality of the material subject to fading.

The fact is due to the physics involved and the problems that are beyond the control of solar window film,
YOU CANNOT UNDER ANY CIRCUMSTANCES COMPLETELY STOP FADING
However, you can do a very good job of slowing it down with solar window film.

solar energy

There are 3 main energy sources which make up the solar spectrum namely Infrared Rays (53%), Visible Light (44%), & UV Rays (3%).

Infrared rays are felt as heat, visible light can be seen & UV rays are invisibe heat.

Solar energy

Ultraviolet (UV) Rays

UV rays occupy only 3% of the solar spectrum but it is also this same 3% that causes skin cancer and causes 40% of fading in homes & offices.

There are 3 types of UV Rays

UV-A Rays:

These have the ability to penetrate the skin’s second layer. Plays a major part in skin ageing and wrinkling. Accounts for 95% of the UV radiation that reaches the earth

UV-B Rays:

The chief cause of skin reddening & sunburn. Burns unprotected skin in as little as 15 minutes and damages the skin’s top layers and DNA which is why these rays are strongly linked to cancer.

UV-C Rays:

These rays are filtered out by the earth’s atmosphere  and are not usually considered a risk for skin cancer.

making your windows more energy efficient

Below are 2 common methods of measuring heat transmitted through windows but the best method would be SHGC method because it takes into account all 3 energy sources of the solar spectrum making it the preferred measure of solar heat transmittance through glass.

u-value

U value comparisons

Window efficiency is measured as a U rating, and it determines how much heat is conducted through your windows. The lower the U value, the better. Single pane windows conduct heat very easily and therefor have a high U rating of about 6.

One of the ways of making a building more energy efficient and lowering the U value is by installing Double or Triple glazing, but this could be a very costly exercise as most of the older buildings only have single glazing.

By installing solar control window film you improve the insulating performance of your home without costly window replacements. Solar window film significantly cuts down on heat transfer and it costs about a quarter of the price that double glazing fitments would.

solar heat gain coefficient

solar heat gain coefficient

Solar heat gain coefficient is the fraction of solar heat that enters the glazing system and becomes heat. This includes directly transmitted heat as well as absorbed heat which is then transmitted to the inside.

The SHGC measurement is always expressed in number values from 0 to 1. The lower the SHGC values are the less heat there is being transmitted from the outside to the inside.

One of the ways of making a building more energy efficient and lowering the SHGC is by installing Double or Triple glazing.

By installing energy saving window film you dramatically improve the insulating performance of your home without costly window replacements. Solar window film significantly cuts down on heat transfer and it costs about a quarter of the price that double glazing fitments would.

not all solar control films are recommended for all glass types

Carmeleon assumes no risk or liability for glass breakage whatsoever!

All films are recommended, preferably silver. Caution – please determine whether the glass has a history of breakage and if so, silver is a must.

Some Perspex or acrylic have had film applied successfully. However, each product has different expansion and contraction and once film has been applied, the film can cause ridges to form on large sheets. No guarantees offered.

All films are recommended for this application. A pressure sensitive film must be used. Dry adhesive films will not bond properly to polycarbonate.

All silver reflective films in 20%, 35%, and 50% densities are recommended. Tinted glass functions by absorbing the heat and holding it in the glass. Coloured film (reflective and non-reflective) also absorb heat. This combination can produce more heat build-up than the glass can tolerate and could cause the glass to crack.

Because the glass has been edged, carved or contains wire, it has already been weakened. Not recommended for film application unless owner accepts risks. No guarantees offered.

All safety films can be applied to armour plate or tempered glass.

All silver films are recommended. Please note the darker the window is tinted, the lighter the silver film is recommended.

All colour film is acceptible for application to this glazing type.

Only silver reflective window  films are recommended to this glazing type. This type of glass builds up heat between two panes. Coloured films absorb more heat than the silver reflective films.

The combination of coloured films and shatterproof or solar shield glass can produce more heat build-up than the glass can tolerate and could cause the glass to crack. If the silver reflective is not appealing then a 35% black non reflective is an alternative to opt for.