Selected Problems of Heat Transfer Measuring by Hotbox Apparatus in Climate Chambers

Abstract

Hotbox measurements are used for obtaining U-values of homogenous or non-homogenous samples in climate chambers for some time. With constant increase of the thermal resistance and lowering the thermal loss arise the problem of these measurements. This is caused by the limited minimal wattage of the hotbox. This paper deals with the measurement in climate chamber, which purpose was to made calibration of the chamber and various measurements equipment. The calibration was made with usage of sample with high thermal resistance, extruded polystyrene. Described problems are chamber and hotbox limitation, sensors accuracy and high thermal resistance of the sample.