Improving Heat Flux Measurement Accuracy: Effects of Sensor Screening and Temperature Inputs

Paper in proceeding, 2026

Accurate heat flux measurements are essential for evaluating the thermal performance of building components. However, surrounding radiation can significantly distort readings from surface-mounted heat flux sensors. ISO 9869-1 recommends using protective screening and surface temperature measurements to mitigate these effects. This study investigates the influence of six cover types and the inclusion of surface temperature measurements compared to air temperature alone. Experiments were conducted in a controlled climate chamber using a test rig with two heat flux sensors mounted on opposite sides of a specimen, one exposed to a heat source. Each cover type (A–F) was tested in three configurations: covering only the exposed side, both sides, or only the unexposed side. Without surface temperature measurements, deviations from theoretical heat flux ranged from 0.05 to 16.33. Incorporating surface temperature reduced this range to 0.03–1.09, demonstrating a substantial improvement in accuracy. The results also indicate a tendency for increased heat flux when covering only the unexposed side. While the findings confirm the benefit of surface temperature measurements, further research is needed to identify the optimal cover type for highest accuracy.