In recent times various energy efficient products have been developed to satisfy the requirements of governments and local councils throughout Australia to minimise harmful effects on the environment. Improved energy efficient building materials including glass, have reduced the demand on natural resources required for artificial heating and cooling of domestic and commercial properties. By taking advantage of northerly elevations and using improved shading techniques, contemporary architecture has made better use of natural solar heating whilst preventing unwanted heat. Modern design trends have seen a merging of the outside and inside of homes by introducing large areas of glass, which in some situations require high performance glass to achieve higher energy efficient results. The challenge for today’s architects is to find a balance between enhanced design and the use of energy efficient products to create a cost effective solution to building.
The infiltration of UV radiation through glazed windows and doors is the main cause of deterioration and fading of furnishings and other items within buildings.
Solar Energy Transmission
While natural light and solar energy plays an important part in architectural design, excessive sunlight can be undesirable and cause uncomfortable conditions for occupants. Controlling solar energy transmission is the most important factor in determining the internal climate of homes and commercial buildings.
Glass types – Single glazed
Annealed clear glass has minimal energy efficient properties, therefore requiring other means of shading or protection for the elements. The PVB interlayer in clear laminated glass, blocks most damaging UV radiation but does not aid in reducing solar energy transmission.
Body tinted glass
Body tinted glass absorbs heat generated by the sun and can provide considerably more protection from the elements than normal clear glass. Selection of thickness can influence performance because the thicker the glass the darker the tint, therefore absorbing more heat.
Performance reflective glass
The innovative solar control benefits of performance coated glass significantly reduces solar transmission while simultaneously offering high levels of light transmission. In most cases a reflective coating is fused into the surface of either annealed or laminated glass to provide a durable product. The coated surface must be positioned on the internal surface of the glass as it is more suseptable to damage when located on the external surface.
The key feature of Low-E glass is its ability to reduce the amount of heat transferred through glass whilst allowing beneficial wavelengths to enter. In some circumstances Low-E may not be the most practical energy efficient glass product to use, therefore a case by case approach should be utilised to guarantee an appropriate product is used.
Insulated Glass Units / Double glazing
Double glazing or otherwise known as insulated glass units (IGU), consist of a combination of any two types of glass sealed together but separated by an airspace creating a vacuum. A specially designed aluminium spacer containing drying agents ensures no moisture is present within this area. Although IGU’s are the most expensive form of energy efficient glass products, the benefits in terms of decreased winter heat loss, and solar, UV and noise reduction makes this type of glazing a superior alternative.