English

Ventilation is essential for the maintenance of good indoor air quality, although there is evidence to suggest that energy loss through uncontrolled or unnecessary air infiltration is excessive. In this study; estimates are presented for air change (ventilation and infiltration) energy use in non-industrial buildings for 13 countries. Various methods are used for the estimates, but they are mainly based on calculating the total annual enthalpy change needed for the conditioning of air. The potential for reduced energy use by improved ventilation control is also briefly reviewed.

Buildings located in noisy areas require a high degree of sound insulation. This will usually involve making the building envelope virtually airtight, and as a result losing the possibility of utilising natural ventilation. The solution is to employ a mechanical ventilation system, but such systems can themselves constitute a source of intrusive noise. Discontinuities in ducts result in the generation of flow noise and a loss of static pressure. The greater the discontinuity, the greater is the loss in static pressure and the greater is the sound power generated.

Perceived air quality, symptoms, and perception of the environment were studied in a naturally ventilated office building in which a felt carpet was substituted by linoleum on the first floor and by polyolefine floor tiles, known from previous studies to be a low-polluting floor material on the second floor, while the felt carpet remained unchanged on the ground floor. A panel of 36 untrained subjects occupied the offices on each storey for a period of one hour in a balanced design on a day when normal occupants were absent.

Perceived air quality, Sick Building Syndrome (SBS) symptoms and productivity were studied in a normally furnished office space (108 m3) ventilated with an outdoor airflow of 3, 10 or 30 L/s per person, corresponding to an air change rate of 0.6, 2 or 6 h-1. The temperature of 22°C, the relative humidity of 40% and all other environmental parameters remained unchanged. Five groups of six female subjects were each exposed to the three ventilation rates, one group and one ventilation rate at a time. Each exposure lasted 4.6 h and took place in the afternoon.