Validation of a coupled BES-HAM model with experimental data

The room moisture balance of buildings typically consists from moisture production, convective moisture exchange by ventilation or infiltration, moisture gains or removals by HVAC systems and moisture absorption and desorption by interaction with hygroscopic surfaces. In typical building energy simulation (BES) programs e.g. TRNSYS the latter is generally simplified since the focus is mainly on predicting temperature and energy use. On the other hand, many building applications require an accurate prediction of the interior relative humidity from the design stage. This paper presents the validation of a recently developed BES-HAM model by experiments in a climatic chamber (6.12m(3)). In one of the walls of a well-insulated and vapour tight test chamber a calcium silicate test sample (0.20 x 0.20 x 0.10m(3)) was installed. Additionally large calcium silicate plates were introduced in the test chamber. In the experiments the response of a test chamber to variations of the supply air relative humidity was investigated: the relative humidity was 50% for two hours, after a step change to 70% was imposed for two hours. This cycle was repeated several times. The measured temperature and the relative humidity both in the test chamber as on different depths in the calcium silicate sample were compared with calculated data and gave satisfactory agreement. Furthermore, the possible influence of hysteresis on the simulation results was evaluated