This study was based upon a laboratory comparison of two air duct cleaning methods, mechanical brushing and compressed air cleaning. These methods were compared in three types of round air ducts: a metal duct without oil residual, a metal duct with oil residual, and a plastic duct. The level of cleanliness was estimated both by using the vacuum test method and visually, and the time each method took was recorded. Two rotating speeds of the brush and various brush materials were used.

Several problems can occur if the design, installation and maintenance of HVAC systems fail to follow appropriate standards. These include excessive installation and maintenance costs as well as hygiene problems produced by dust deposition and accumulation. There is no proper set of standards for biological risk assessments to prevent ventilation system pollution. All there is are a few guidelines on limit values of bacterial and fungal air concentration.

Many occupants of a Swedish office building reported symptoms typical of sick building syndrome (SBS). Tests showed that the supply airflows were inadequate, but there was poor air movement in the rooms. Much of the supply air never reached the occupants but went direct to the exhaust system. Reducing the temperature of the supply air improved its dispersion. Instead of rising, the air sank towards the floor and then circulated through the entire room.

Many occupants of a Swedish office building reported symptoms typical of sick building syndrome (SBS). A questionnaire was constructed to rate occupants'

The importance of IAQ to Finland's society and economy has led to the realisation that nationally planned and coordinated activities are necessary to achieve reliable results. For 20 years the Finnish government has had a national policy to coordinate different governmental, local and private policies to improve IAQ in homes, schools, offices, public places etc. This program has been very successful although there are still many buildings with damp, mould and other similar problems and the quality of construction falls below that required.

During extreme weather conditions, the poor quality of windows and doors in several dwellings led to a high number of air changes. This created physical and psychical discomfort for the occupants. Recently better quality windows and doors were installed which led to the infiltration air exchange rate decreasing and heating costs falling. Unfortunately mildew formed in many apartments.

This paper is based upon the results of measuring and simulating the air change in the single apartment of 5-storey multi-family dwelling. The technique of tracer gas concentration decay was applied to be able to assess the rate of air change. The building was used as normal by occupants so the results should be very accurate. The main aim of the research was to validate simulation methods used to predict infiltration. Multiven -the authors own program - was used to achieve this aim.

This study discusses the results of site measurement and surveying for IEQ in several of Shanghai's multi-storey buildings. It shows that there is no connection between data from objective measurements and surveys of office workers in questionnaires. Indeed in some cases the results were completely contradictory.

This study investigates the viability and cost effectiveness of natural ventilation in Istanbul. A typical high-rise office building was used for the investigation together with detailed local weather data including average temperature, wind speed and wind directions for each month of an average year. Data and methods provided by ASHRAE is used to calculate the air pressure at a particular window taking into account wind speed and direction, outside temperature, height and the building's location. The study uses a simple computer program to do this.

The effectiveness of personalized ventilation based on air movement around a room's occupant largely depends on the supply air terminal device or ATD. Five different ATDs were tried and compared. A normal office workplace with a desk and mounted ATDs was simulated in a climate chamber. An office worker was simulated by a breathing thermal manikin. Tests were performed at various air temperatures of 26C and 20C and personalized air temperatures of 20, 23 and 26C provided by the ATD. The flow of personalized air was increased from less than 5 L/s up to 23 L/s.