We want you to understand the options available to you so you can make the right choice for your home.
Clear float.
Clear float is the most commonly used glass type in New Zealand homes today. It has a slightly green hue due to the iron content found in the glass but this is not highly noticeable when viewing through your windows.
The green hue is only noticeable when there is a white (or similar) background or if it is placed next to a low iron glass which has a reduced green hue.
All thicknesses over 4mm can be toughened to produce Grade A Safety Glass to meet NZ Safety Standard NZS 4223: Part 3: 2016
Clear float of 4mm and over can be used in double glazing.
Obscure glass.
Obscure Glass is a great way to provide privacy for areas such as sidelights next to wooden doors, bathroom and toilet windows or any other space where you don’t want the outside to easily identify what’s inside.
Obscure Glass is usually made using the same process as clear float, with the glass moving through an additional patterned roller before the cooling process. Etchlite differs as it has acid applied to one surface to achieve the etched appearance.
Patterns provide privacy and design whilst still allowing heat and light to pass through the window.
All of our obscure options can be toughened to produce Grade A Safety Glass to meet NZ Safety Standard NZS 4223: Part 3: 2016 and can be used in double glazing.
Tinted float.
Tinted float was traditionally used to reduce the amount of heat and/or light entering a home through window glazing. It is produced using the same process as clear float with metals such as cobalt, boron or iron being added at the beginning of the process, giving the glass its tint. Grey and green tint are most commonly used.
With the introduction of high performing Low E double glazing such as SuperTherm™ Low E double glazing, tinted glass is no longer the best option for insulation performance though it is often selected to provide privacy inside.
Consideration to thermal stress should be considered when selecting tinted glass. We recommend toughening tinted glass when adding to double glazing to improve its thermal strengths, reducing the risk of thermal cracks or breakage.
Be aware when matching tints: tinted float does not exactly match tinted laminate. This is because the laminate tint is provided by the coloured interlayer, not the glass tint.
Tinted float over 4mm thick can be toughened to produce Grade A Safety Glass to meet NZ Safety Standard NZS 4223: Part 3: 2016 and used in double glazing units.
Toughened grade A safety glass.
Toughened glass is used where improved thermal and operational strength is required. Toughened (or tempered) glass is annealed glass that processed to become four to five times stronger than annealed glass of the same thickness and can withstand substantially higher point loading than annealed. Additionally toughened glass responds with a larger temperature change (of around 250°C) than annealed glass, giving greater thermal strength.
To toughen glass, first the edges of the glass are arrissed or polished to remove the sharp 90° edges. Any other processing required is carried out prior to the glass reaching the furnace. Next the glass is moved into a special heated furnace where it is heated to around 650°C where it is heated to a plastic state.
It is then moved into an area called the quench, where it is snap cooled. This rapid cooling puts the surface of the glass into a state of compression. The inner core of the glass remains in a state of tension. This combination of tensions provide the increased strength of toughened glass.
In addition when toughened glass is broken, the stored up energy is released and the glass breaks into small pebbles around the same diameter as the glass thickness keeping you safer than annealed that can break in a large sheet.
Grade A Safety Glass so it can be used in situations where human impact risks are high and human impact standards are required to be met.
Low-E - SuperTherm™ glass.
Low-E glass (or ‘low emissivity glass’) contains a coating of fine silver particles on its surface that changes the response of the glass to a portion of the light spectrum. It is specifically “tuned” to “select in” the energy that is required to pass through the glass and “select out” the energy that should not pass through the glass.
– Clear glass has high emissivity – it transmits a high proportion of thermal energy in the light spectrum.
– Low-E glass has low emissivity – it reflects a high proportion of long-wave infrared back in the direction it came from.
There are different types of Low-E in the market, all with different appearances and differing levels of performance. Some respond to light such that they can appear “hazy” in direct sunlight, while others maintain a high degree of clarity.
Low-E glass can be categorised into two types, based on its response to light:
– Solar control Low-E glasses – which are designed to transmit high amounts of visible light and reflect infrared light
– Passive solar Low-E glasses – which are designed to transmit high levels of both infrared and visible light.
Selecting the right Low-E glass for the right area of your home can make a significant difference in the resulting comfort levels year-round.
The SuperTherm™ double glazing range contains an exceptional set of solutions designed to meet the requirements for creating a comfortable environment in the respective areas of your home.
High-performance SuperTherm™ Low-E glass is superior in four areas:
– High clarity. The product has no haze
– High neutrality. The glass looks natural
– High transmission of visible light
– Thermal insulation effectiveness. The glass has a U Value that is 1.1W.m2 °C or lower
SuperTherm Warm™ high-performance Low-E has been specifically designed and selected to capture, and keep in, maximised thermal energy from the sun. SuperTherm Cool™ high-performance Low-E has been specifically designed and selected to allow a balanced level of radiant heat from the sun without compromising thermal insulation.