How to Choose Vacuum Glass: Applications, Climate and Energy Savings

With its excellent thermal insulation performance, vacuum glass is increasingly used in residential windows, curtain walls and public buildings. However, different applications require different product configurations. How should vacuum glass be selected? Which climate conditions are suitable? And how much energy can it save?

The right configuration depends on the application, safety requirements, and the building's thermal performance needs. Also consider the project location and climate conditions to ensure the selected vacuum glass meets applicable building energy-efficiency requirements.

Q1: Which Type of Vacuum Glass Should I Choose?

A: The appropriate vacuum glass configuration should be selected according to the specific application:

Standard windows: Single vacuum glass or vacuum insulating glass can be selected according to the required thermal, acoustic and structural performance, as well as project cost considerations.

Curtain walls: Vacuum insulating glass or vacuum laminated glass can be used. In some system configurations, positioning the vacuum glass toward the interior side can help protect the vacuum glazing from external environmental conditions.

Skylights and overhead glazing: Vacuum laminated glass combines the thermal insulation performance of vacuum glass with the safety characteristics of laminated glass, helping reduce the risk associated with glass breakage and falling objects.

Floor-to-ceiling windows and doors: Laminated configurations can be used where additional safety is required, helping keep broken glass together and reduce the risk of falling glass.

Q2: Which Climate Zones Are Suitable for Vacuum Glass?

A: Vacuum glass can be used in a wide range of climate regions. In China, it can be applied to new construction, renovation and extension projects, provided that the thermal performance of the selected product complies with applicable building energy-efficiency standards.

Vacuum glass can provide thermal insulation benefits in severe cold, cold, hot-summer-and-cold-winter, and hot-summer-and-warm-winter regions. The appropriate glass configuration should be determined based on the local climate, building envelope design and applicable energy-efficiency requirements.

Q3: How Much Energy Can Vacuum Glass Save?

A: The energy-saving performance of vacuum glass depends on the specific project and glazing configuration. Key factors include:

Local climate and heating or cooling demand;

Building design, including window-to-wall ratio, orientation and solar shading;

Window frame material, such as aluminium, thermally broken aluminium or uPVC;

Vacuum glass configuration, including glass thickness and the use of Low-E coatings.

Compared with conventional insulating glass, vacuum glass can significantly reduce heat transfer through the glazing area when appropriately configured. Under suitable conditions, heat transfer through the window area can be reduced by more than 50%.

The actual energy savings of a building should be evaluated based on the complete window system and overall building energy model rather than the glass alone. In long-term operation, reduced heating and cooling demand may help offset the initial cost difference between vacuum glass and conventional glazing.