Window Energy Efficiency

Altair® Louvre Windows are an energy efficient way to control natural light and fresh air into your home or office environment.

Energy Efficient Altair Louvre Windows

Reduce your energy bill with Breezway

At Breezway, we believe buildings should be designed to work with nature, rather than sealing up and fighting against it. Breezway Louvre Windows allow air conditioning and artificial lights to be turned off so you can live naturally. View the energy video below to learn more.

Altair Louvre Windows offer the following benefits including:

  • Increased energy efficiency, health and productivity of building occupants.
  • Reduced need for air conditioning to keep the room at a comfortable temperature, saving electricity and the running costs of a building.
  • Low U-values required for energy efficiency compliance/excellence.

To learn more about the benefits of natural ventilation, Breezway has produced a number of Technical Bulletins to assist with your building designs. These include:

Fixed WindowFixed Window

0% Fresh air

Awning WindowAwning Window

12% to 30% Fresh air depending on wind direction

Sliding WindowSliding Window

40% Maximum fresh air

Breezway Altair Louvre WindowBreezway Louvre Windows

90% Fresh air regardless of wind direction

Cross Flow Ventilation

The importance of window placement.

Good Ventilation with Breezway Louvre WindowsGood
Better Ventilation with Breezway Louvre WindowsBetter
Best ventilation with Breezway Louvre WindowsBest
Excellent ventilation with Breezway Louvre WindowsExcellent

Internal Ventilation

Ventilation openings are often needed in internal walls. Ventilation openings in internal walls are great for internal ventilation The drawing above illustrates how a ventilation louvre between rooms is more efficient than just having external louvre windows alone.

Thermal Chimney Effect

Installing windows up high. Installing windows up high create a Thermal Chimney Effect Another good way to naturally cool a room is to place some Altair Powerlouvre Windows up high. This is effective because rising hot air is able to escape the room through the high up louvres, helping to keep the room cool.

Solar Control

Tinted glass

Controlling solar heat gain is important so you can keep out sunlight in warmer months but let sunlight in during cooler months to keep the home a comfortable temperature without the need for artificial cooling or heating. Clear glass blades give a high solar heat gain however all windows can use tinted glass to reduce the solar heat gained (SHGC) through windows. A low SHGC indicates that less solar heat is gained through a window, and this is desirable in hot climates and on western orientations. A high SHGC indicates that more solar heat is gained through a window and is desirable in colder climates and on northern orientations.


Altair Louvre Windows can:

  • Achieve a low a Solar Heat Gain Coefficient when using glass blades (E.g. Tinted glass blades help reduce solar heat gain).
  • Achieve very little Solar Heat gain by using timber or aluminium louvre blades to completely block out the sunlight while still allowing maximum ventilation through the window.
  • Prevent Solar Heat Gain by angling blades while still allowing ventilation.
  • Reduce Solar Heat Gain when using metal mesh screens

breezway solar control


Seal tight window

The last thing that you want is windows that don’t seal tight and let in rain or draughts. Altair Louvre Windows provide tight sealing due to:


  • The living hinge design that resists water and air penetration between the clips and the channels.
  • An over centre locking mechanism which applies strong locking pressure to blades when fully closed.

Breezway tight sealing windows


U-value ratings

U-values are the measure of the thermal conductivity of the window. That is, if there is a temperature difference between the air on either side of a window, it measures how quickly heat will pass through the window.


Low U-values allow heat to be transferred through the window slowly, and a high U-value indicates that heat is transferred quickly. The greater the difference between the desired indoor temperature and the outdoor temperature, the more important U-values are. In temperate climates where the outdoor temperatures are seldom extremely hot or extremely cold, the U-value is relatively unimportant.

Altair Louvre Windows can achieve rather low U-values when using tinted glass blades.

Breezway Louvre Windows in the bedroom