Traditionally air has been supplied from the ceiling to the occupants below opposing the buoyancy effects due to heat convected from people, lights and machines. There has also been concern that if air supply outlets are installed at low level near people the chances of draughts and noise are high. The development of swirl air diffusers in Sweden and Germany overcomes these problems and allows a wider consideration of air distribution systems when designing buildings. This also offers flexibility in planning the distribution of electrical systems and piped services.
The paper describes measuring results of the air movement from three different types of diffusers for displacement ventilation. Two of the diffusers are lowlevel wall mounted diffusers, one with a low and one with a high initial entrainment. The third diffuser is of the floor mounted type. The air flow close to the diffusers and in the rest of the room is analysed. Velocity decay in the flow from the low-level diffusers is given as a function of the Archimeaes number, and the paper suggests a general equation for this part of the flow.
An experimental study in reduced scale model for ventilation inside a sheep-fold has been studied. The ventilating system consist of two slots in opposite side walls and one in the roof, Two-dimensional jet are generated by the wind effect and temperature difference acting upon the sheep-fold.
Diffusion-type passive monitors were placed for a two-week period in each of 303 residences in the New Haven (Conn.) area during a 12 week sampling period January to April 1983. For each home NO2 levels were recorded outdoors, and in three ro
Discusses causes of condensation between the panes of a double window. Treats movement of water vapour by diffusion and by air leakage separately. Describes tests made to determine air flow and vapour diffusion through test windows finds that relative importance of the mechanisms depends largely on the inside to outside pressure difference so that the higher the pressure difference, the greater the importance of air leakage. Suggests venting of windows to overcome condensation.