Error estimation of measurement methods by computer simulation

Computer  simulation  Of  measurement  methods  can give in-depth information on the possible effect of a wide variety of parameters on measurement results. Examples for computer simulation of simple U-value measurements of building components for  the appraisal of retrofit measures and more complex examples of building airtightness measurements with the blower door method are given. The simulation models used are described in detail and results for example cases are given. For simple U-value measurements the simulated measurement accuracy is compared for different measurement strategies and building construction types. The impact of transient thermal behavior of different constructions on measurement accuracy is considered for different load functions. The computer simulations show, that simple methods for U-value measurement usually lead to very poor results. The accuracy heavily depends on transient behavior of the building construction. The uncertainty in measurement results of building airtightness measurement with the standard blower door method and derived methods is simulated. For the standard blower door method the uncertainty due to changes in pressure distribution across the building envelope because of wind force and temperature difference is discussed. The wide range of leakage distributions, wind directions and velocities considered