Cooling Performance of Air-Conditioning System with Ceiling Suspended Packaged Air Conditioning Unit over Divided-Type Membrane Ceilings in Large Classroom

The mainstream of air-conditioning system for medium and small sized buildings is conditionally air mixing ventilation with ceiling cassette unit of packaged air conditioner (PAC), however, it may bring a high cold-draught risk to occupants, due to the direct drop of the supply air jet. To solve this problem, the air mixing ventilation system can be improved into an air based radiant air-conditioning system by stretching the non-flammable membrane under the ceiling with PAC, thus the cold-draught of PAC could be substantially eliminated and the indoor environment could be improved easily.

Laboratory assessment of flexible thin-film membranes as a passive barrier to radon gas diffusion

This paper presents the experimental results of utilizing a flexible thin-film membrane as a passivebarrier to radon gas diffusion. Nine commercially available membranes of various compositions andthicknesses were evaluated as retardant to radon gas diffusion. The radon gas concentration ratiosacross the thin-film membranes alone and in combination with an adjacent concrete sample (effectivediffusion coefficient) were measured in a laboratory system with state-of-the-art instrumentation.