The performance of a STRAD system was greatly affected by
the locations of diffusers. Kuo and Chung [6] studied the effects
of the inlet and outlet diffuser’s locations in the occupied region
on the thermal comfort. By comparing the simulation results from
different ventilation strategies, they claimed that the longer the
cold air throw in the occupied zone, the better the thermal comfort
that may be obtained. Wan and Chao [7] conducted experiments to
study the thermal performance of a floor return (FR) type under-
floor system under different heat load densities and supply air
temperatures. The results indicated that a comfortable environment
can be maintained by the FR type system under a dense
internal heat load conditions with a supply air temperature at
18 ◦C. Li et al. [8] investigated the relationship between the air
flow pattern and the distribution of air age in a test chamber.
They concluded that the location of return air inlet had influences
on the distribution of air age, but the effect was not great.
Holmberg and Chen [9] worked on the air flow and particle distribution
in a classroom with different ventilation system. They
intended to minimize the respirable airborne particle concentration
in the breathing zone. The numerical results indicated that the
exhaust inlet location in a DV system played an important role on
the particle concentration in breathing zone. With an additional
exhaust inlet below the breathing zone, the inhaled air quality can
be improved. The locations of diffusers not only greatly affected air
quality and thermal comfort, but also significantly influenced the