October 16, 2009
Hot Dry/Mixed Dry


The software CONTAM was used to create a calibrated multi-zone model to replicate in-field tracer gas decay measurements of a new two story, 2600 ft2 (240 m2), single-family house in Sacramento, CA under different whole-house dilution ventilation scenarios. The model incorporated measured values of ventilation system airflow rate, building enclosure leakage, fan-forced mixing between floor levels, indoor and outdoor temperature, and wind speed and direction. The enclosure leakage distribution was adjusted to tune the model to the measured tracer gas concentration data. The calibrated model was then used to compare different ventilation systems under identical outdoor conditions over a one-day period. Zones that received more ventilation air had faster concentration decay rates compared to zones that received less ventilation air. Results showed that ventilation systems that delivered air to all zones, either by a dedicated duct system or by incorporation of the central forced-air space conditioning system, had more uniform ventilation air distribution.