Stratum Ventilation for a Retrofitted Classroom

摘要

There is worldwide plea to reduce carbon emission. Several governments in East Asia recently have responded by setting higher indoor temperatures in summer. But the public need to be convinced that such practice would not sacrifice indoor environmental quality, especially thermal comfort of the occupants. To implement such a measure, suitable ventilation system(s) to work under the unconventional conditions should be identified. Stratum ventilation, a new mode, is proposed for the elevated indoor temperature. The purpose of the research was to find out whether the new ventilation mode is feasible for the warm condition. A stratum ventilation system is installed for an experimental classroom. Experimental investigation and/or computational fluid dynamics simulation are used for the study of airflow and pollutant transport in the room. Various factors including percentage dissatisfied (PD/DR) and mean air age are calculated to determine the performance of the ventilation system. Results show that for the classroom, the system is able to provide air of young age without the penalty of over-cooling lower part of a room, to maintain thermal comfort with a smaller temperature difference between the head and foot level, lower energy consumption, and better indoor air quality (IAQ) in the breathing zone.