About window film
Benefits
Window film is an ultra-thin polyester-based material that can be professionally installed on most glass surfaces to…
- Reduce heat on hot days
- Retain warmth on cold days
- Lower energy bills
- Increase safety and security
- Minimise glare
- Improve comfort
- Block UV radiation
- Protect furnishings, carpets, artwork, etc. from fading
- Create a stylish look
- Ensure privacy
- Provide signage and decoration
- Shield from electromagnetic interference (EMI)
As it’s retrofit to existing windows, window film increases energy efficiency at a fraction of the cost of new, high-performance windows. That’s why it’s so popular with renovators.
Many films sold in Australia have an independent energy rating attained through WERS For Film (the Window Energy Rating Scheme). NB: this scheme operates in Australia only, not in New Zealand.
When a WERS rated film is installed by a WERS For Film accredited installer, an energy certificate is issued, which can contribute to the building’s energy assessment and help increase it’s sale price.
Modern films are manufactured in many different shades, colours and constructions covering everything from very dark to nearly invisible. This gives each film unique performance characteristics that impact their suitability on different glass types. Your WFAANZ window film installer is trained to match the right film to your glass.
Some of the many reasons people get their windows tinted…
Performance
To understand how much heat a window film can block, you need to know its TSER.
TSER stands for Total Solar Energy Rejection. Expressed as a percentage, it describes the amount of heat that’s prevented from passing through the glass. The higher the TSER, the more solar energy rejected.
Energy from the sun is divided into three categories that each bring heat – ultraviolet, visible light and infrared (IR).
WFAANZ considers the use of IR values in isolation misleading for two reasons. Firstly, different companies use different ways to calculate IR values, so you’re not comparing apples to apples. Secondly, IR rejection only tells a small part of the total heat rejection story.
To accurately compare films from different suppliers, look at the TSER values of films with the same visible light transmission (VLT). In other words, compare the TSER of films that are the same darkness.
Any reputable Australian or New Zealand film supplier, and certainly all WFAANZ distributor members, will be able to give you the TSER value of its films.
To learn more about TSER, IR values and how to understand the heat rejection ability of window films, download the Heat Rejection Fact Sheet.
Application
Your windows represent a huge investment and they should be treated accordingly. It is not a DIY job, or something your handman/woman or builder should take on if they haven’t been properly trained. Always use a professional with the right credentials and experience – and the best way to find that person is to use a WFAANZ member.
When they join the industry association, WFAANZ installer members make a commitment. They agree to abide by a strict code of ethics and comply with Australian and New Zealand Standards. That’s why their WFAANZ membership is your assurance of quality.
Window film is usually applied to the interior surface of the glass, which increases its lifespan as it’s protected from the elements. There are some exterior films available too, for sites where internal access is restricted, for example.
Your WFAANZ member installer will advise how long it will take to install the film, as it will depend on many variables like access, frame type, condition of the glass, etc.
Why should you use a professional tinter?
- Professionally installed films look better, last longer and are more likely to meet their warranted lives, or even longer, than those improperly installed
- Professional tinters have experience and/or training to help them identify circumstances that may affect either the installation or performance of a certain film in a particular location
- Warranties offered on quality films installed by professional installers usually cover costs of removal, costs of replacement film, and costs of re-installation
Drying time
Water is sprayed onto glass before film is applied. It enables accurate positioning and helps remove air pockets. A thin layer of this water remains once the film is installed. Days after, you can expect to see bubbles – don’t panic, this is completely normal.
The bubbles can be any size and quantity, depending on the glass, film and environmental conditions. The water between the window and the film will evaporate over time and the bubbles will diminish.
Download our drying time fact sheet for more information.
Types
1. Solar control window film
Energy from sunlight does one of three things when it hits glass:
- Passes through (transmittance)
- Bounces off (reflectance)
- Goes into the glass itself (absorption)
In reducing the visible light passing through glass, window film reduces the amount of heat and UV rays entering the room or vehicle. Reflection and absorption rates also increase. The transmittance, reflectance and absorption rates achieved with film vary according to the type of film and glass.
Facts about solar control films:
- Almost clear, low reflective films are now available ensuring minimal change to the look of the glass, so retaining light while providing considerable thermal benefit
- When choosing film for your home, ask for a WERS rated film
- Range in darkness, from almost transparent to dark grey
- State and Territory Australian laws govern the darkness of car tint
- Homes or buildings can have film of any darkness
A WFAANZ member can recommend the right film for your needs.
2. Low E window film
If you live in one of Australia or New Zealand’s many mixed climate zones with hot Summers and cold Winters, a Low E window film may be your best option.
The ‘E’ stands for ‘emissivity’, which relates to a material’s ability to emit radiant energy. So Low E window films emit less infrared electromagnetic energy than other materials, which results in less heat transmission through the glass.
According to WFAANZ distributor members, Low E films can help retain as much as half the heat inside the room on cold days, and block as much as half the heat entering the room on hot days.
Download our Low E fact sheet for more information.
3. Safety and security film
The idea behind safety and security film is that it creates a membrane that holds the window together in the event of breakage. So instead of glass shards flying out from a broken window or door, they stay in place on the film. This helps prevent injury to person or property damage, and also makes it harder for thieves to access a building or vehicle.
- Usually clear
- Uses a safety-strength adhesive
- In Australia, glass can be brought up to safety standard AS/NZS 2208:1996, Grade A safety glass in human impact situations
- Applied to any smooth glass surface, internally or externally
- Different colours and thicknesses are available – the thicker the film, the stronger the substrate it’s applied to becomes
- Also comes in solar control, UV reduction safety and security film
- Special sacrificial anti-graffiti films are also available, which absorb scratch graffiti and can be replaced
Download our safety and security film fact sheet for more information.
4. Decorative films
- Frost film used for office privacy (think of the frost stripes on the office walls in your local bank)
- Coloured vinyl films used in the signage industry
- Digitally printed films can depict just about any design or artwork
- If privacy is an issue, frosted or decorative films allow more natural light than closed blinds or curtains
5. Anti-grafitti film
Vandals tagging glass and other surfaces using mechanical etching tools, acid and spray paint is problem encountered in cities across the globe.
Anti-graffiti film cost-effectively mitigates the damage.
These specially designed films, almost invisible once installed, provide a removable, sacrificial surface that can reduce or eliminate the need for expensive glass or other surface replacement. A single replacement of just one window can easily exceed ten or twenty times the cost of film installation. Anti-graffiti films are ideal for use in houses, shops, buses, trains, bus stops, etc.
Maintenance
While film is made of strong polyester and has a tough scratch resistant coating, it can still be damaged by improper care. Firstly, don’t clean your window for thirty days after film has been installed. You need it give it ample time to dry, and for the bubbles to disperse.
Listen to advice from your installer, as they’ll provide tips specific to your situation. Keep in mind…
- A soft, damp chamois or microfibre cloth works best
- Use ammonia-free window cleaner or mild detergent diluted with water
- Scourers, brushes or abrasive products should be avoided
- Don’t use suction grips, adhesive glue, tape or any similar products
- Use a rubber squeegee, not a plastic one
Download our maintenance fact sheet for more information.
Composition
Film is made with a polyester base, which can be pre-treated to accept different types of dyes or coatings, then it’s laminated to other layers of film which could be clear or have coatings as well. These layer combinations produce a variety of colours, reflectivities, thermal properties and so on, each with its own purpose and attributes.
Layers could include (this list is not exhaustive):
- Clear: non-reflective, used for safety and security film or UV control
- Dyed: contain no metals and are non-reflective; provide glare and fade control and reduce heat gain by primarily absorption; variety of colours
- Metallized: metals deposited on the film in very thin layer/s; major solar control and Low E ability; can be reflective and even low reflective; can be spectrally selective meaning they reject glare and block heat while providing visible light and optimum clarity
- Carbon: non metallic, corrosion free. Carbon Black pigment is applied to the film with energy handling properties primarily through absorption
- Ceramic: a non metallic layer, corrosion free. Primarily absorption of solar energy especially in the IR wavelengths. Can also be nano ceramic meaning the ceramic particles are deliberately much smaller in size resulting in greater overall particle surface area increasing the ability to absorb energy.
Warranties
WFAANZ recommends you always use a film that’s covered by a warranty. Different films come with different warranties, which are issued by the distributor of the film. Ask your WFAANZ installer or distributor about the warranty covering your chosen film.
In terms of the installation of the film, you’re best served hiring a WFAANZ member. These tinters abide by a strict code of ethics which requires compliance with all relevant regulations. They’re kept updated on industry best practice, and by virtue of their membership commit to upholding the standards of the industry.
ADVICE FROM WFAANZ…before you hire a tinter, ask about the installation and film warranty conditions, and importantly, ensure you’re given the paperwork to support the warranty and proof of purchase. Keep that paperwork in your files. If something happens down the track, you must have that paperwork to ensure the fulfillment of warranty obligations.
WARRANTIES IN NEW ZEALAND…the New Zealand Building Act 2004 does not provide for product warranties. However, the Department of Building and Housing Codewords article from July 2007 explains the difference between the Building Code durability requirements and two different types of warranties for building work – product warranties and implied warranties. For more information visit www.dbh.govt.nz
The Department of Building and Housing states: “In the example of retrofit window film, warranty requirements are on a case by case basis, but generally, if the film forms part of the main component, then it must be able to last for the same durability time left of that component to meet compliance with the building code.”
Understanding performance claims
Heat transfer through glazing is a complex issue, so you’ve got to watch out for misleading claims. That’s why WERS For Film is so useful. The data is independently verified, so you can accurately compare products from different distributors.
Some things to look out for…
Temperature reduction
WFAANZ considers to be misleading unsupported claims of internal temperature reduction (without calculation or appropriate reference).
Reducing solar energy is the purpose of most films. Solar energy reductions following a film installation can be calculated simply and with reasonable accuracy using local weather files. Glass + film performance can be calculated by the distributor, and local weather files indicate the levels of solar energy hitting the window.
However, the reduced solar energy load through the windows does not provide enough data to calculate ambient room temperature.
Calculating ambient temperature reduction requires complex calculation and extensive building information. Size, shape, air conditioning system details, building materials, occupant numbers, occupancy patterns throughout the day and geographic location. Interaction of all these aspects contribute to ambient temperature at any given time.
Infrared (IR) heat or infrared energy reduction
WFAANZ considers the promotion of infrared rejection values in isolation is misleading to consumers. Look out for the TSER value, not the IR rejection value.
Energy (or light) from the sun is divided into three wavelength categories – ultraviolet, visible and infrared. All sunlight brings heat, so to properly calculate how much solar heat a window film can reduce, the sun’s whole spectrum must be considered.
Infrared from the sun brings about half the heat, the other half comes mainly in the visible light wavelengths and a small amount in UV.
A film’s infrared reduction tells only part of the story. A particular window film may have an infrared reduction of say 90%, but the actual net heat rejection may be only 50%.
The true indication of heat reduction through glazing is the film’s Total Solar Energy Rejection (TSER). This is calculated across all the sun’s wavelengths and even includes the portion of heat that is absorbed by the glass and reradiated inwards. Any WFAANZ member promoting an infrared performance value must also declare the film’s TSER.
Angled heat rejection
Angled heat rejection can be a point of interest, but consumers should be aware the phenomenon is present for all glass and window films.
When window films are measured with laboratory equipment for their solar performance, the heat source is directed straight on or perpendicular to the sample. This is the reporting standard.
A consumer may also want to know the angled heat rejection.
What this means is that at say 2pm when the outside temperature is hottest, the sun is high in the sky and the sunlight striking the glass is at an angle, not perpendicular. The solar energy reflection of the glass + film in this case increases, so the total solar energy rejection (TSER) of the glass + film increases.
This is not a unique property of window film. Clear glass alone, with a very low reflection normally, can be highly reflective when the light source is at a sharp angle.