Thermal properties of building materials evaluated by a dynamic simulation of a test cell

Abstract

A method for the measurement of thermal properties of building components under controllable conditions is presented. It is based on the use of a test cell designed to enable calculation of thermal properties solely from temperature readings, without the need for power measurements. The test cell’s low thermal inertia allows short testing times (about 3 h). Using an appropriate thermal network to simulate the dynamic behavior of the test cell, predicted results were found to have a 0.6°C maximum temperature deviation with measured test cell responses. The thermal transmittance (U-value) of an insulating block, a single glass sheet and a double glazing have been measured with an accuracy of about 5%. A simulation of a scaled-up test cell with dimensions 6.0 m×6.0 m×4.5 m has revealed that the test cell’s response to temperature changes depends strongly on the amount of wall insulation. The scaled-up test cell exhibits a relatively fast response to temperature changes (9 to 18 h) due to its low thermal mass.