Annual characteristics of ventilation and indoor air quality in detached houses using a simulation method with Japanese daily schedule model.

In order to explain the effect of ventilation systems, the article presents the results of investigations made on a simulation program to calculate the temperature, heat loads, ventilation rates and indoor air quality. The study considered the Japanese daily schedule and the residents behaviour in regard to maintaining comfort. The indicators of indoor air quality were taken to be carbon dioxide, carbon monoxide and formaldehyde concentrations. Three systems were analysed: basic passive ventilation system, a passive stack ventilation system and a mechanical ventilation system. Weather data from three cities in Japan were used for the simulation. The results clearly showed the seasonal variation. For the passive ventilation system, spring and autumn show high risk of indoor air pollution, and the first floor differs from the second floor. Discusses the performance of the ventilation systems and the solution methods.