Validation of a Zonal Model to Capture the Detailed Indoor Thermal Environment of a Room Heated by a Stove

Abstract

Using wood stoves is a common space-heating strategy in the Nordic countries. Currently, the lowest available nominal power of wood stoves is significantly oversized compared to the design space-heating load of highly-insulated houses. This oversizing might deteriorate the indoor thermal environment by causing overheating and a large vertical temperature stratification. Modelling the indoor thermal environment of rooms heated with a wood stove with acceptable computational time and accuracy, however, is a complex task. The purpose of this study is to analyze the accuracy of a new IDA-ICE zonal model currently under development and to calibrate it against measurements. For this, several experiments were conducted in a test cell, which was heated by an electric stove mimicking a wood stove with a nominal power of 4 kW. Room air temperatures in various positions were measured, while the stove that was placed in the middle of the room was run in cycles with different durations and surface temperature profiles, leading to a thermal stratification of 0.5–2.2 K/m. The zonal model could reproduce the temperatures at the bottom and top layers of the room with good accuracy. However, the model still needs further development and validation to reach good agreement with measurements in the middle layers of the zone. Nevertheless, already at this stage, the model could be used to roughly assess thermal stratification in rooms heated by wood stoves.