What the lab researches

G-Value Lab

The g-value: how energy-permeable is glass?

In the G-Value Lab, we improve planning for new buildings and renovations.

Our scientific team measures energy transmittance, also known as the g-value or solar heat gain coefficient (SHGC). The g-value indicates what proportion of the radiated energy permeates through transparent components. We examine transparent and semi-transparent elements and those equipped with shading systems. By carefully measuring the g-value, we can evaluate the performance of single glazing, as well as complex and innovative building envelopes, thus improving the design of new buildings and renovations.

We measure the g-value of windows and other (semi-)transparent building elements.

The laboratory consists of a solar simulator, a climatic chamber for controlling the test conditions (temperature and relative humidity), a support structure where the test element is mounted and where the absorber is located – measuring the energy flow passing through the test specimen – and a hydraulic circuit for disposing of the dissipated energy. Our tests can be tailored to the customer’s needs at various levels of complexity. Aside from standard solar factor measurement tests, our researchers offer customised tests that can help improve prototypes and develop new solutions.
The g-value can be measured in different ways:
• by measuring the heat flux using a heat flux measuring plate
• by measuring the input and output temperature and the flow rate at the absorber
• by applying electrical resistance

Profit from what we offer: we put our know-how at the service of the economy

Through international research networks, the experts at Eurac Research have gained expertise in the fields of energy efficiency in buildings and natural lighting. Using this know-how and the flexibility of the laboratory, we support companies and planners in analysing and optimising the performance of individual building elements and developing innovative technical and architectural solutions.
What do you want to research? Choose which test of glass building elements will help meet your company’s goals:
• Testing of glass and shading elements
• Testing the energy performance of windows
• Solar simulator tests
• Testing/measurement of solar factors
• Measurement of energy transmittance (g-value)

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