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

With its excellent thermal insulation performance, vacuum glass is increasingly being used in residential windows, curtain walls and public buildings. However, when choosing between different product configurations, many users still have questions: Where should vacuum glass be used? Is it suitable for my project? And is it worth the investment?

Where it is used determines the appropriate glass configuration. Standard windows, curtain walls, skylights and floor-to-ceiling doors have different requirements for safety and the position of the vacuum layer. Whether it is suitable depends on the climate zone of the project location and whether the thermal performance of the vacuum glass meets applicable energy-efficiency requirements. Whether it is worth the investment ultimately depends on whether the long-term savings in heating and cooling costs can offset the additional product cost.

Q1: Which type of vacuum glass should I choose?

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

Standard windows: Single vacuum glass or vacuum-insulating glass units can be selected to balance thermal insulation, sound insulation, cost and overall performance.

Curtain wall systems: Vacuum-insulating glass units or vacuum-laminated glass are generally suitable. The vacuum glass is preferably positioned on the interior side to help protect the vacuum layer from harsh outdoor environmental conditions.

Skylights and overhead glazing: Vacuum-laminated glass should be used to combine the thermal insulation performance of vacuum glass with the safety characteristics of laminated glass, helping reduce risks associated with falling objects or glass breakage.

Areas with high safety requirements, such as floor-to-ceiling windows and doors: Laminated configurations should be considered to help prevent broken glass from falling out of the frame.

Q2: Which climate zones are suitable for vacuum glass?

A: Vacuum glass can be used in most climate regions of China. It can be applied in new construction, extensions and renovation projects, provided that its thermal performance meets the requirements of applicable national building energy-efficiency standards.

Whether in severe cold, cold, hot-summer-and-cold-winter, or hot-summer-and-warm-winter regions, vacuum glass can provide effective thermal insulation and help buildings meet their energy-efficiency requirements.

Q3: How much energy can vacuum glass save?

A: The actual energy-saving performance of vacuum glass depends on several factors, including:

Local climate conditions and heating or cooling demand;

The building's overall thermal design, including window-to-wall ratio, orientation and solar shading;

Window frame materials, such as aluminium, thermally broken aluminium and uPVC;

The specific vacuum glass configuration, including glass thickness and whether a Low-E coating is used.

In general, compared with conventional insulating glass, vacuum glass can reduce heat transfer through the window area by more than 50% under appropriate configurations and conditions, significantly improving the thermal performance of the window system.

Over the long term, reduced heating and cooling costs may help offset the higher initial cost of vacuum glass, making it a potentially cost-effective solution for energy-efficient buildings.