English

A cross-sectional study was carried out to investigate the occurrence of the sick building syndrome (SBS) among office workers in Mauritius. A walk-through inspection and a questionnaire survey were carried out in 21 office building complexes to evaluate the prevalence of risk indicators for SBS symptoms among 302 office workers. Indoor climatic variables monitored were: carbon dioxide, carbon monoxide, nitrogen dioxide, air temperature, relative humidity, air movement, noise and light. All data collected were analysed using the EPl-info software.

Nosocomial infectior1s are a major problem in many hospital buildings, with ,approximately 10% of patients acquiring such an infection during a hospital stay. Airborne transmission is one of the important routes for a number of nosocomial pathogens. To combat this proq,lem there are a number of engineering control strategies, such as the use of ultraviolet germicidal irradiation and advanced ventilation techniques, which can be used. This paper outlines the 'state of the art' in air disinfection, and reviews recent research work in this field.

Control of indoor pollution sources and ventilation are both means of improving indoor air quality. Three independent experiments have recently documented that removing a pollution source or increasing the ventilation rate will improve perceived air quality, reduce the intensity of several Sick Building Syndrome (SBS) symptoms and improve the productivity of office workers.

The impact of unintentional air flows on the performance of ventilation units with heat recovery is discussed on the basis of single room ventilation units. Assuming an external short circuit (outdoor) and internal (inside the ventilation unit) air leakages, which lead to internal short circuits, a model is developed and characteristic numbers for ventilation efficiency, efficiency of heating load reduction and effectiveness of electrical energy use are derived.

More than three-fifths of the households in the U.S. heat or cool their homes with ducted forced air systems, so chances are good that air ducts are lurking within your walls, floors, or ceilings. These air ducts move conditioned air to warm and cool your family. They can be a great source of comfort-but more likely they are wasting energy and costing you money. Typical duct systems lose 25 to 40 percent of the heating or cooling energy put out by the central furnace, heat pump, or air conditioner.

Good indoor air quality (IAQ) enhances occupant health, comfort and workplace productivity. This issue has become more critical in a country like Singapore that has no other natural resources except manpower. In addition, Singapore is located in the tropical region with a hot and humid climate and a large number of the buildings are served by air-conditioning and mechanical ventilation (ACMV) systems to maintain a thermally comfortable indoor environment. The provision of a thermally comfortable indoor environment for the occupants is only one aspect in achieving better indoor air quality.

Much publicity has been given to the potential health risks posed by buildings, particularly those with mechanical ventilation or air conditioning. There have been concerns over the possible effects of the vocs given off by the furnishings and finishes, of fungal spores shed from dirty ducting, of legionella distributed by wet cooling towers, of insufficient ventilation air, etc., etc. The list of concerns is a long one. But what about the effects on the building occupants of the air brought in from outside, the so-called 'fresh air'?

We analyzed 1994 sick leave for 3,720 hourly employees of a large Massachusetts manufacturer, in 40 buildings with 115 independently ventilated work areas. Corporate records identified building characteristics and IEQ complaints.