English

The demand for duct cleaning has been increasing exponentially over the last few years and to determine objectively if the duct is dirty and has to be cleaned is necessary.All air-handling units from a school district (18 buildings) and representative portions of their associated ductwork were assessed. Results of dirt and contamination are compared to dirt criterias and commented.

Physico-chemical and microbiological measurements (temperature, humidity, CO2, CO, VOC, bacteria and fungi) were performed on indoor air of three schools near Paris (France). Results of measurements are given and analysed. Indoor air quality is better with mechanical ventilation than in operable windows classrooms. TVOC concentrations are much higher indoors than outdoors.

Indoor environmental measurements (temperature, CO2, formaldehyde, TVOC) were operated in 28 classrooms in Warsaw (Poland). The classrooms were equipped with natural ventilation systems. Air change rates were calculated from CO2 concentrations. Results are compared with Polish regulation and international requirements and standards. The natural ventilation systems applied in all schools do not ensure proper ventilation rate.

Four relocatable classrooms were designed, constructed and tested in Californian schools to demonstrate technologies that improve energy efficiency and indoor environmental quality. First results such as CO2 and particle concentrations are presented and discussed.

A Norwegian research project in under progress to develop a new concept for control of air movements in protection isolates, operating theatres and other risk areas in hospitals. The aim is to reduce airborne hospital infections through appropriate design of building, HVAC installation and control of air movements. A container solution was developped for isolates. Its HVAC system, and especially the ventilation system are described in details. The first container has been finished in June 2002 to be tested.

Practical application on two buildings (a movie theater and an office building) of the Indoor Air Quality Procedure described in ASHRAE Standard 62 is demonstrated. It shows in particular how air filtration can achieve acceptable indoor air quality and energy savings (by reducing outdoor air flowrate requirements).

An energy audit calculation procedure has been developed for existing buildings. It allows to estimate which measures have to be taken to improve the thermal performance of building envelope. An example of the application of this calculation procedure is presented.

Indoor aerosol particulate matter (PM) concentrations were measured gravimetrically in 36 carpeted bedrooms of asthmatic children. Particulate concentration was higher indoors than outdoors. High efficiency particule arresting (HEPA) filtration was shown dividing concentrations by about 2.

The filtration efficiency of residential furnaces air filters was measured in several houses in Canada. Even efficient filters have a minor influence on particulate levels in houses. The ways to reduce these levels were investigated. Results show for example how HEPA filters on supply air reduce indoor particle concentration.

Several previous calculations have shown that many of the measures taken to improve indoor air quality and climate are cost-effective when the potential savings are included into the calculations as benefits. However, general models on how to estimate the cost-effectiveness of various measures and strategies are still missing. This paper presents approach with which the ratio of savings in any of the costs of owning and operating a building can be compared with the real cost at risk which is reduced worker performance.