Development of air supplied ceiling radiant air conditioning system using the Coanda effect

Air-supplied ceiling radiant air conditioning is expected to become more popular in Japan in the future because there is no leakage from pipes and no condensation on the surfaces of radiant panels. Coanda air conditioning, a type of air-supplied ceiling radiant air conditioning, uses the Coanda effect, which is the tendency a fluid passing near a wall to maintain contact with it. As used commonly, Coanda air conditioning cools the ceiling surface by blowing airflow horizontally along it from the top of the wall surface and cooling by radiation1).

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.