FAQ: FAQ

FREQUENTLY ASKED QUESTIONS

WHAT ARE DOUBLE GLAZED WINDOWS?

Double glazed windows use insulated glass units (IGU). The IGU has two glass panes in the one window system. These are generally double glazed, that is, with two panes of glass.

A still layer of gas or air and a spacer separate the glass panes in these systems. The spacer is made of a metal or polymer strip, usually with a drying agent to dry out any moisture in the space. It is then all placed in a window frame, made wider to fit the extra pane.

WHY ARE ML WINDOWS BETTER QUALITY THAN MOST YOU’LL FIND IN AUSTRALIA?

We’ve completed extensive research and selected manufacturers that specialise in high quality windows using high quality components. We’ve visited the factories to ensure they can deliver what they say they can. We aren’t the lowest cost supplier of double glazed windows but our prices are competitive for the quality that we offer. We aim for the balance of quality, sustainability and affordability.

ML windows are commercial premium quality. They are European style and have been exported to Europe and North America as well as to Australia. All our windows are made with high quality aluminium frames with multiple thermal breaks, gas filled air gaps, multiple locking points to make them very secure. They also come with stainless steel flyscreen for additional security and perfect for bush fire zones.

WHY DO WE NEED DOUBLE GLAZED WINDOWS?

Double glazed windows are significantly more energy efficient than single glazed windows.

They help keep the cold outside in winter and keep the heat out in summer. Double glazed windows are also excellent at reducing external noise. It's ideal if you live on a busy road.

Double glazed windows can significantly reduce or even eliminate condensation in winter.

ARE TRIPLE GLAZED WINDOWS NECESSARY IN AUSTRALIA?

The answer I’m afraid is complicated. It comes down to what is important to you. If you want a home with a 9 or 10 star energy report or you are building a passive house or you are really trying to reduce your energy bills to as low as possible, or you live in the high countries or near the coastline, then triple glazing is certainly worth considering.

WHAT DOES LOW E COATING ON GLASS MEAN?

Low E means ‘Low Emissivity’ – emissivity is defined as the amount of radiation emitted or absorbed from a surface.

The main difference between a Low E glass and an ordinary glass is that Low E glass has a very thin coating applied to one side of the glass. This enables a reduction in the transport of heat or cold through the glass. Think of it as an invisible insulation barrier for your windows.

Just as wall and ceiling insulation provides protection to those areas, Low E glass does the same for glass. Coated glass helps provide a more comfortable temperature in a room, more window area can be used as an added bonus, and heating and cooling costs are reduced. Combining better insulated products into our homes makes sense and contributes to reducing greenhouse emissions.

WHAT ARE THE DIFFERENCES IN WINDOW FRAMES?

In general, there are three different types of frames that double glazing and fit into.

uPVC - Usually, the lowest cost material to make frames out of, they have been used in the northern hemisphere for over 40 years. However, uPVC frames have to be made with an additive here in Australia to combat high UV. uPVC frames are thermally efficient. However, they usually require an internal aluminium or steel frame for added strength. uPVC frames are effectively plastic and don’t perform well in bushfire zones.

Timber - Possibly the most expensive material to use, but very thermally efficient. They also have the highest ongoing maintenance due timber rotting if it’s not maintained well.
Aluminium - Aluminium frames are possibly the strongest and most robust of all the different frames available, but they have the major disadvantage of conducting heat or cold straight through the frame. Aluminium frames with a thermal break are basically two frames that have been joined by an inert joint that effectively stops all heat transfer across the frame. For this reason they are slightly more expensive than normal aluminium frames, but the advantages of strength and thermal efficiency greatly out way the disadvantages. ML Windows only used Aluminium with thermal break as we consider this the best of all the options.

WHAT DOES THE U VALUE MEAN?

In its most simple form, the U value is a measure of how energy efficient a window and frame are.

The heat transfer through a window (or any part of a building) is measured using a “U value.” (measured in Watts / square metre Kelvin), The lower the U value is, the lower the rate of heat transfer.

Double glazing typically has a much lower level of heat transfer than a single glazed window. A typical single glazed window has a U value of 5 or 6. While a decent U value for double glazing is around 2, figures of 1.5 are more than achievable.

In general, the lower the U value, the more expensive the window will be.

WHAT ARE THE ADVANTAGES OF DOUBLE GLAZING?

Energy efficiency

Approximately 20% of heat is lost through single glazed windows. Double glazed windows absolutely come out on top when it comes to energy efficiency. The sealed air or gas gap between panes of glass acts as thermal insulation. They lock in the cool air from your air conditioner in summer, leaving the unwanted heat outside.

In winter, they stop heat escaping from your home. By reducing heat transfer through your windows means you can use your heater and cooler less.

This adds up to enormous savings on energy, especially since our energy bills keep rising, which is six times the average pay increase. With no long-term solution to every increasing power prices, consumers need to look for ways to offset household energy costs. One way to do this is to install double glazed windows which in turn means dramatically reducing your power bill.

Noise reduction

Double glazing dramatically reduces noise from busy streets

Safety and security

Double-glazing of windows improves both safety and security. They are harder to break than normal windows, ML Windows only uses toughened glass. That means they are safer around children and also make breaking in harder. All our opening windows utilise multi locking pints, depending on the size of the windows from two to four different locking points around the frame. Our windows can only be replaced from the inside so they can’t be taken out by criminals from outside the property.

Reduction in condensation

Double glazing almost completely eliminated condensation, thus reducing mould.

WHAT ARE THE DISADVANTAGES OF DOUBLE GLAZING?

Cost

The main disadvantage of a double glazed window is the added expense. There is no denying that they cost more than single glazing, which is why builders prefer single glazing as it keeps their outlay lower. The price difference between single and double glazed windows is perhaps 20-30% higher.

Upfront and retrofitting

If you consider the cost of replacing single glazed windows with double at a later date, the cost becomes almost double what the original cost would be.

WHAT IS SHGC?

Solar Heat Gain Coefficient or SHGC is a measure of how much solar radiation passes through the window. In a cool climate, windows which have a high SHGC allow a greater amount of solar radiation to pass through, offering free solar heating for the home. Glass selection as well as Low E coatings have a considerable effect on the SHGC of a window or door.

SHGC is measured between 0 and 1. With 0 meaning no transmission of solar heat and 1 meaning all the solar heat is transmitted through the glass.

So what is a good number and what is a bad number? Unfortunately, there is no correct answer to that. You need to determine how much heat do you want to gain from the sun and how much heat do you want to block?

In a cool climate a higher SHGC will allow more solar heat to pass through the window and help to heat the home, whereas in a warmer climate a lower SHGC will allow less solar heat to pass helping to keep the home cooler.

Glass tints and low-e coatings are some of the options to consider to get the best result for your home.

Things to consider when choosing your windows are:

The climate of your build or renovation location.
What are the building materials that interact with the windows? E.g., insulation, cladding or other building materials.
The design of the building. E.g., orientation, layout window position and size, roofing or shading.
Double or triple glazing, thickness of the glass, types of glass and coatings also play critical role in manipulating SHGC.

WHAT IS THE ML WINDOWS PRODUCT WARRANTY?

We are confident and proud of our product quality. We offer 8 year warranty for manufacturer defects. We will fix them for free. It includes any functional issues, handles and parts, rubber seals. It doesn’t include general wear and tear or any accidental damage that is not caused by us or our manufacturers.