Noise Radiated by Circular Ventilation Ducts

Noise remains a major concern for building occupants, both in their home and workplace. Ventilation system is one of the noise sources in buildings. Usually, the main issue is the resulting noise level in the room. It is generated by the fan and the ductwork components, travels inside ducts, and is then radiated into the room by air diffusers, air inlets, and air outlets. But ducts also go through other indoor spaces. Airborne noise will pass through the duct wall and radiate in the surrounding space. This can be an issue for occupants. 

Natural ventilation of heat-intensive factories. Preliminary instructions. Naturliche luftung von warmeintensiven betrieben. Vorlaufige richtlinie.

Outlines the foundations for calculating and designing natural ventilation: conditions for the building unit: technological prerequisites: components: sound insulation: calculation methods: fields of application: combination of mechanical and natural ventilation: and models for optimization of new buildings and for reconstructing factories.

Indoor air pollution and ventilation in sound insulated dining kitchens.

Presents new data acquired by experiments on the ventilation rates and the indoor air pollution caused by combustion in the dining-kitchens of sound-insulated houses. Ventilation rates were measured by means of tracer gas decay, using CO2 and CO as the tracer gases. Indoor air pollution was estimated from the elevation of CO and CO2 levels, and the effect of supply or exhaust fan systems on the control of ventilation was deduced from the level of air pollution and ventilation rates.

Air tightness and infiltration rates in houses.

Reports the results of investigations by researchers at the University of Osaka into the air tightness and infiltration rates in houses built with high levels of noise-reducing insulation.