COMPARISON BETWEEN MEASURED AND SIMULATED LONG TERM VARIATION OF VENTILATION IN AN EXTRACT VENTILATED HOUSE

Using a passive tracer gas technique, 1 and 2 week averages of local mean ages of air have beenestimated in an occupied detached single family house in mid-Sweden during one year. In this paperthe measurement result is compared with the result of transient simulation of ventilation using theCONTAM program. The simulation shows that the whole-house air change rate is dominated by theinfiltration due to mechanically created pressure difference as long as the outdoor temperaturedifference exceeds approx. 10 C. At lower outdoor temperature, the natural driving force becomesincreasingly more important increasing the local air change rate (local ACH) in the basement. However,the local ACH on the ground floor is almost independent of indoor-outdoor temperature difference andcompletely dominated by the mechanical extract. The result from the simulation can reproduce theresult of the measurement in satisfactory detail without using wind pressure data.