SERIS’ Calorimeter laboratory enables high-precision measurements of the thermal performance of building façade assemblies and fenestration systems, including building-integrated PV systems (BIPV).
Calorimeters are used to accurately measure the solar heat gain coefficient (SHGC or G-value) of complex façade or fenestration systems (including shading devices) and the overall thermal transmittance (U-value). Both values are direct indicators of the energy efficiency of building façades. A low solar heat gain coefficient is preferred in the tropics in order to minimise solar radiation heat gain through fenestration systems. High solar heat gains increase the temperature in the building and thus the air conditioning costs. In the tropics, moderately insulated building elements (U-value) are already sufficient to reduce the transmission of absorbed solar heat and ambient heat through the building envelope to acceptable levels.
SERIS’ calorimetric hot box is a combined solar heat gain coefficient (SHGC) and U-value measurement system with the following features:
SERIS’ calorimeter is superior to the more commonly used calorimetric hot-plate systems, which are limited to flat samples (as they need to be sandwiched between two plates). It is also superior to the optical determination and calculation of the SHGC with spectrophotometers, which is limited to small, flat and homogeneous samples (and which furthermore requires detailed information on the thermal properties of all components/layers of the sample). SERIS’ calorimetric hot box can measure samples ranging from 0.3 m x 0.3 m up to 1.5 m x 1.5 m.
The calorimetric hot box at SERIS is designed in compliance with the international standards ASTM C1363 (Test method for thermal performance of building materials and envelope assemblies by means of a hot box apparatus) and ISO 8990 (Thermal insulation - determination of steady-state thermal transmission properties - calibrated and guarded hot box).
The large integrating sphere (diameter 1.25 m) system at SERIS was built in compliance to DIN 5036-3 (Radiometric and photometric properties of materials: Methods of measurement for photometric and spectral radiometric characteristics). The system can accurately measure the optical transmittance and reflectance of materials in the visible wavelength range.
For commercially available spectrophotometers, the diameter of the integrating sphere is typically in the range of 6 to 15 cm. SERIS’ integrating sphere is much larger and thus the system has many advantages over standard spectrophotometers. First, it is able to measure large, inhomogeneous and non-specular samples (for example frosted or patterned glass panes, or fabric shading materials). Second, it is able to measure the transmittance and reflectance of samples as a function of the angle of incidence of the visible light. The SERIS system is also able to determine the diffuse and specular components of the optical transmittance and reflectance.
For further information, please contact:
Dr. Veronika SHABUNKO