History of Glass
Glass may be one of the oldest known man-made materials, how and when it was first discovered is unknown. Glass dating back to 7000BC has been found. It is believed that the art of making glass was perfected by the Egyptians. The basic ingredients used to make glass have remained relatively unchanged for many years but the most significant changes to glass making have come in the manufacturing process with the increasing ability to use high levels of heat.
Blowing glass into a large glob, which was then spun to expand its circumference, made the first windows, as we know them. Subsequently, this mass was pressed against a flat surface creating a circular sheet of glass, flatter on one side than the other, but roughly uniform thickness. It was cut into a square pane and despite air bubbles and poor clarity it provided light transmission.
The French perfected fine glass-making and learned how to grind and polish these panes so that they were much thinner. This allowed higher levels of visible light and better optical clarity.
Introduction to Solar Control Window Film
The biggest problem in controlling comfort in homes and office buildings is dealing with the radiant heat from the sun. The energy generated by the sun literally pours through windows and is absorbed by all it touches. The greater the glass area of a building, the more potential for excessive radiant heat gain.
Outside walls and roofs also absorb radiant heat from the sun, which is then transferred by a process referred to as conduction towards the inside of rooms. Heat can also radiate from warm objects such as furnaces, light bulbs, ovens etc…
One of the most outstanding characteristics of solar control window film is its ability to regulate or control the amount of solar energy that passes through glass. Safety and security protection is another tremendous benefit offered by various types of window film.
Benefits of Solar Control Flat Window Film (For Residential and Commercial Use)
The concept of metallized window film (silver based) for use in solar control flat glass application dates back to the early 1960’s. Such early films were found to reflect solar radiation back from a window, preventing the warming of inside surfaces normally hit by direct sunlight while still allowing vision through the glass. As the window film concept was developed and improved upon, a demand developed for coloured sun control films that would complement architectural design.
The energy crisis of the early 1970’s prompted an interest in another aspect of window film use, the reduction of heat loss to the outside. It was discovered that polyester film tended to absorb and re-radiate long wave infrared heat rather than act as a transparent medium.
The brochure below covers the main benefits of flat film –
• solar heat control
• ultraviolet radiation control and fading,
• improved protection from shattering glass and
• building appearance and aesthetics.
Click here to open the Flat Glass Window Film Brochure.
Types of Solar Control Window Film (For residential and Commercial Use)
Solar control window film reduces the transmittance of light and infrared heat through glass windows and doors thereby reducing heat gain. This feature provides the following basic consumer benefits:
– Improves energy cooling efficiencies
– Reduces energy consumption and utility costs
– Improves living comfort and working conditions
– Balances hot/cold spots in buildings
There are three basic categories of solar control window film:
– Clear (non-reflective)
– Dyed (non-reflective)
– Vacuum coated (reflective)
Click here if you would like to read an energy study commissioned by the International Window Film Association in 2012.
GO TO ‘FIND THE RIGHT FILM’ TO VIEW THE RANGE OF SOLAR CONTROL WINDOW FILMS AVAILABLE IN NZ
Safety and Security Window Film (For Residential and Commercial Use)
The primary function of safety film is to hold the glass intact in the event of it being broken. Many events can cause glass to break unexpectedly and every year hundreds of thousands of people around the world are injured, maimed or killed by lethal shards of flying or falling glass. Many glass breakage events are not predictable such as an earthquake or a terrorist bomb. In these cases existing buildings may have no form of glass protection, causing a high-risk potential of injury to the property, occupants and damage to the interior of the property itself. In these cases it is prudent to retrofit the glazing with some form of protection to reduce injury and death as well as property damage. One such product that is readily available, and can be installed in a reasonably short period is safety window film. If a window that is coated with this safety window film breaks, the film holds the glass shards intact and in some cases the glass remains shattered but intact in its original frame.
Go to “Find the right film” to view the range of security window films available, or contact a member near you via the link below:
Flat Glass Window Film Standards
Under the New Zealand Building Act 2004, all building work must comply with the New Zealand Building Code. The mandatory provision for safety glass is contained in Building Code clause F2 hazardous Building Materials. One way of complying with the performance criteria is to follow the Department of Building and Housing’s F2 Compliance Document, which cites NZS 4223: Glazing in buildings, Part 3 Human impact safety requirements: 1999.
For more information visit www.dbh.govt.nz/
Glazing must also be considered under Building Code clause B2 Durability which requires a 5 year durability if:
(i) the building elements (including services, linings, renewable protective coatings, and fixtures) are easy to access and replace and
(ii) Failure of those building elements to comply with the building code would be easily detected during normal use of the building.
Standards New Zealand has published a revised Standard specifying Thermal insulation – Housing and small buildings, NZS 4218:2009, which supersedes NZS 4218:2004.
Note that NZS 4218:2004 continues to be cited in the Compliance Documents for the New Zealand Building Code.
NZS 4218 specifies thermal insulation requirements for housing and small buildings for users of the Standard – architects, designers, building consent authorities, and window and glass companies.
‘The Standard is also useful for the building industry including window and glass manufacturers, insulation manufacturers, and manufacturers and suppliers of building products so that they can provide advice and stock appropriate products,’ says Michael Camilleri, committee Chair, from BRANZ. ‘Ambiguities in the previous version of NZS 4218 have been resolved, and there is additional guidance with more worked examples.’
The revised version of NZS 4218:
- includes modified R-value tables and brings the Standard into line with these increased performance requirements. The construction R-values in this Standard result in a low life cycle cost, based on current knowledge of insulation costs, energy costs, and heating behaviour
- clarifies the three different ways of working out R-values (Schedule method, Calculation method, and Modelling method) and ensures consistency between the different methods
- includes clearer definitions.
Some of the most significant changes are:
- adjusted R-values to reflect improved energy efficiency
- changes to the calculation method to ensure adequate thermal performance is not compromised by large glazing areas
- a revised modelling method to take account of recent research, and to make it easier to use with recent computer modelling packages
- new requirements for high thermal mass construction to ensure that the thermal mass is adequate and effective
- a revised appendix (now Appendix C) on windows and glazing
- a new informative Appendix D provides guidance on alterations and how they can achieve higher thermal resistance
- more worked examples in informative Appendix F
- the new term construction R-values has been introduced to distinguish the performance values in this Standard from insulation material R-values.
‘There is more clarity on the use of doors, skylights, decorative glazing, and louvres,’ says Allan Sage, committee member and Glass Association of New Zealand Technical Advisor. ‘Appendix D – Windows and Glazing has been revised, offering more glazing options and guidance for users wanting to calculate other glass and frame combinations. A new term (RWindow) has been introduced to overcome confusion over the R-value for glass only (RCOG) and the total window R-values (RWindow).’
‘The major change for the window industry is the reduction of the limit on glazing area from 50% to 40% for the Calculation method. The Modelling method must be used for a glazing area over 40% of the total wall area. This will see more modelling of complex houses in the future, which GANZ believes is a positive move to stop over-heating and under-heating issues with modern house design.’
To order or download NZS 4218:2009, visit www.standards.co.nz and enter keyword 4218 in the search area, email email@example.com, or call customer services on 0800 782 632. Get the latest Standards news at www.standards.co.nz/touchstone.
Installation of Window Film (For Residential and Commercial Use)
Benefits of installing film correctly
- Professionally installed films look better longer and are usually more likely to perform to specifications for their warranted lives, or even longer, than those improperly installed.
- Professional dealer installers have experience and/or training which can help them to identify unique or unusual circumstances which might affect either the installation or performance of a particular product in a given situation and might not otherwise be noticed.
- The warranties offered on quality films installed by professional dealer installers usually cover costs of removal, costs of replacement film, and costs of re-installation. Film purchased elsewhere will likely only be covered for costs of replacement film in the event of a problem or product failure.
- Remember that the best film installed improperly or used in a situation where a professional dealer installer might not otherwise install that particular film will likely not live up to the customer’s expectations
To find the right film for your specific purpose and to ensure that the film is installed to the highest standards it is recommended to use one of the dealers below.