Stratum ventilation – A potential solution to elevated indoor temperatures

There is worldwide plea to reduce carbon dioxide emission. In response to such a call, several governments in East Asia recently have required to adopt higher room temperatures in summer. To promote such an idea, 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 is introduced to demonstrate its feasibility in coping for the unconventional warm condition. A case study, a typical office in Hong Kong under local thermal and boundary conditions, is used to illustrate the performance of this new ventilation mode. Computational results show that under the warm condition, with properly designed supplied air velocity and volume, locations of supply and exhaust, the proposed system has the potential to maintain better 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. Much further work is needed to determine if the benefits are significant.