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Window Energy Efficiency

Natural ventilation

Altair® Louver Windows provide energy-efficient control of natural light and fresh air in a building. Increasing natural ventilation can improve the health and productivity of building occupants whilst reducing the reliance on air conditioning.

By adjusting the angle of the Breezway Louver Blades, inhabitants can regulate the amount of air that enters their living space, while simultaneously maximising their views of the surrounding landscape. View project.

Maximum Ventilation

Altair Louvers are considered to be the most energy-efficient window on the market, due to their unique ability to provide close to 100% ventilation, which sets them apart from other window systems.

Altair Louvre Window

Altair Louver Window

Awning Window
Awning Window
Sliding Window
Sliding Window
Fixed Window
Fixed Window
Breezway tinted green louvre blades

Solar Control

Controlling the amount of heat entering a home from the sun is important for comfort and energy efficiency. Clear windows let in a lot of heat, but tinted windows can reduce this heat gain. In hot climates and on western-facing windows, a low solar heat gain coefficient (SHGC) is desirable. In colder climates and on northern-facing windows, a higher SHGC is desirable.

Altair Louver Windows:

  • Achieve a low Solar Heat Gain Coefficient (SHGC) when using glass blades and tinted low-e glass.
  • Block out sunlight and allow ventilation with wood or aluminum louver blades.
  • Prevent Solar Heat Gain by angling blades while maintaining ventilation.
  • Reduce Solar Heat Gain with metal mesh screens.
Breezway Living Hinge


Altair Louver Windows provide tight sealing significantly better than the standard required for residential windows due to:

  • A living hinge design that prevents water and air penetration.
  • An over-center locking mechanism for strong closure.
Hawaii Insulation


U-values measure a window’s thermal conductivity, or how quickly heat transfers through it. Lower U-values mean slow heat transfer and higher U-values indicate fast transfer. The importance of U-values depends on the outdoor temperature difference.

Altair Louver Windows have low U-values and can outperform some double-glazed windows when using low e coatings.

Cross Flow Ventilation

The importance of window placement.









Internal Ventilation

Ventilation openings are often needed in internal walls.

Internal ventilation

The drawing above illustrates how a ventilation adjustable louver window between rooms is more efficient than just having external louver windows alone.

Thermal Chimney Effect

Installing windows up high.

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

Energy Efficiency

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

The video explains the benefits of Altair Louver Windows that maximise natural ventilation as well as sealing tightly.

Ventilation Rates & Energy Efficiency

Ventilation is essential to create a naturally comfortable home. This short video compares the ventilation rates of different window types.

Natural Ventilation in Offices Case Study

The Breezway Head Office displays a spectacular showcase of Breezway Altair Louver Windows, in particular the Altair Powerlouver Window that has been integrated into a building management system to achieve a cost efficient, environmentally sustainable commercial building design.


Benefits of energy efficiency

To learn more about the benefits of energy efficiency, Breezway has produced a number of Technical Bulletins to assist with your building designs.