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Huge technological progress has been made in the glass industry; and it’s contributing towards making the buildings that we live and work in more energy efficient and environmentally friendly.

When it comes to windows, doors and other glass fixtures, the type of glass that is used is of critical importance. Did you know that between 40 to 70% of energy loss occurs through windows and doors? And in the case of an installed window, the glass pane is responsible for up to 90% of the heat loss!

Greater energy efficiency can be achieved with Low-E coatings, reflective coatings, glass tints, double glazing, or various combinations of these. Depending on the combinations that are used, the glass will perform differently, some better than others.

But in terms of heat insulation Low-E glass out-performs all the other coatings and tints. It is an incredible technology and highly effective – on its own as a single glazed laminated glass, or in combination with the other tints, coatings and glazings.

What is Low-E Technology?

Low-E, is the common name for “low-emissivity” glass. This high performance glass is specifically designed to minimise the amount of infrared and ultraviolet light that passes through, without minimising the amount of light that enters through the building.

Low-E glass has a microscopically thin layer of transparent coating of silver or other low emissivity materials. This layer helps keep out UV and infrared waves (or heat). Low-E glass keeps heat in and not out which is why it is specified for more of the colder regions

So, how does it work?

Your windows and doors allow the transference of heat in the form of long-wave infrared energy depending on their emissivity and the temperature of their surfaces. Radiant energy is one of the main ways heat transfer takes place in windows and doors.

When interior heat tries to escape through your windows and doors into the colder atmosphere outside during the winter months, the Low-E coating reflects the heat back to the inside. Likewise, during summer it insulates the cool interior temperature by reflecting the outside heat, drastically reducing the heat that passes through the glass.

Performance measurements

There are several factors used to measure the effectiveness of glass with Low-E coating. Performance value and effectiveness standards have various measures:

  • Solar Heat Gain Coefficient (SHGC): This is the fraction of incident solar radiation that is admitted through the window. This can be either directly transmitted and absorbed or radiated inward.
  • U-Value: This is the rating that is given to a window based on how much heat loss it allows.
  • Visible Light Transmittance (VLT): The measure of how much visible light passes through the glass.
  • Light to Solar Gain: The ratio between the window’s visible light transmittance and its Solar Gain Coefficient rating.

So which Type of Low-E Glass is Best for You?

In order to decide which type of Low-E glass is best for you, you need to consider the predominant climate in your area.

  • If you live in an extremely cold climate, the hard-coated Low-E glass may be an option for you, because it allows some of the sun’s short-wave infrared energy to pass through the glass. This helps to heat your home in the winter and allows the glass to reflect the interior long-wave heat energy back inside.
  • However, if you live in a cold to hot climate, like most areas in South Africa, the soft-coat Low-E glass is best, since it offers better UV protection and has a better overall U-value. The soft-coat Low-E coating also reflects the warm and cool air back into your room instead of allowing it to leak outside.

Low-E glass is being used widely for shopfronts and facades. It is now being manufactured on a large scale to make commercial and residential properties more eco-friendly, cost-effective and comfortable. Whether you’re an architect or home-owner, you can now take full advantage of these incredible benefits when choosing Low-E technology! Low-E coatings play a pivotal role in the performance of your windows, can save you money on energy costs and can drastically reduce fading to furniture and décor by blocking UV rays.

Go with Low-E and Pro

At Pro Aluminium, we take care to specify the most suitable performance glass for each individual project. If you’re eco-conscious, and looking to reduce your electricity costs, speak to us about fitting your windows and doors with Low-E glass.

Keep in mind that our double glazing option is another great way to make your building more energy efficient. And if you want to double up the benefits, we can combine both technologies, which will increase your property’s green energy rating and save you thousands of rands in the long run.

Ready to lower your energy bills with Low-E windows and doors? Speak to our friendly sales staff today at 031 701 2001 (Durban) / 010 003 1889 (Johannesburg), or fill out a quote request form for your providence: KZN / Gauteng.

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