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National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluation Reports (lllIER) involving schools provide a perspective on the building-related factors associated with indoor air quality complaints. Generally, the school lffiERs reflected multiple building factors associated with the complaints.

This paper describes radon diagnostics and mitigation in a school the U.S. Environmental Protection Agency (EPA) classified "difficult to mitigate." The school had subslab utility tunnels that served as the outside air and return air mixing chamber for the heating and ventilation system. The heating and ventilation system depressurized the tunnel, sucked radon from the soil, and distributed it to school rooms. Extensive diagnostics were conducted to test mitigation options and to provide mitigation design parameters.

In a room with a raised floor HV AC system (RF system), the vertical temperature gradient became an important factor in relation to the ventilation requ1rement to maintain a vertical temperature difference within a comfort standard such as ASHRAE Standard 55-1992. A series of detailed laboratory experiments were carried out to obtain the design ventilation requirements with various conditions of ventilation rates, cooling loads, and types of floor outlets. The main results are shown as follows.

In some ventilation and dust removing system of workshop, a great deal of energy is wasted due to heated and cooled indoor air being exhausted directly. So if the dust in the indoor air is removed and then recirculate, the objective of energy saving can be reached. In this paper, the calculation equation of dust concentration, relative humidity in indoor and recirculate air and heater capacity are given along with the control measures to them.

The results from the Norwegian project "Indoor Environment in Schools" show a reduction from about 80 % to 55 % in complaints of poor indoor air quality just after renovation, and to 10 % after another year. There was clear accordance between the renovation enterprise with the measured indoor climate and the pupils own opinion of the working environment. Norwegian authority has set a limit of CO2-concentration to 1000 ppm, and our results indicate that the amount of outside air has to be 9 Vs per person to be sure of getting under this limit.

The purpose of the study was to assess actual ventilation, indoor air quality and also the quality of repairing process in the Finnish schools. The measurements that included ventilation rate, co2 and particle concentrations, and temperature and humidity in the classrooms were carried out in 20 schools. Repairing of schools were studied on the basis of 32 schools. The typical needs for repairing HY AC-systems and building structures and also typical repairing measures and faults were reported. The most common problem was the classrooms' old-fashioned or even missing ventilation devices.

In a university building in Boston, IAQ complaints prompted an increase in outdoor air ventilation, causing a large increase in energy use. C02 readings were then taken in an auditorium, cafeteria, offices, and classrooms. The readings were used to calculate occupancy estimates and to simulate operation of a demand-controlled ventilation (DCV) system. The differential equations were solved in a spreadsheet program using a Runge-Kutta macro. A PID control system was also simulated. Ventilation adjustments were input to DOE-2 to estimate energy savings. A two year payback was estimated.

The CO2, H2O and CO content of the indoor and outdoor air in the four libraries of the University of La Coruiia (Spain) was monitored for 48 hours. For this a multipoint monitoring system was used, based on the infra-red photo-acoustic spectroscopy technique. This allowed us to identify the conditions of air renovation of indoor air with natural ventilation. Although good outdoors air quality was observed, the indoor air quality, on the other hand, was seem to deteriorate considerable during the periods of occupation.

This paper involves assessing radon concentrations at the heating, ventilating and air conditioning (HV AC) environment of Hong Kong University of Science of Technology (HKUST). Ninety rooms with various configurations were selected at random and evaluated in detail. A time-integrated active sampling instrument as well as a passive activated charcoal canister radon detection system were used for the study. With the central HV AC system in the normal operating mode, data on location characteristics, as well as average and peak radon concentrations were collected and analysed.

This paper describes the management of radon concentrations at the Hong Kong University of Science and Technology (HKUST). Applying our derived specific modification factor in the radon concentration predictive mathematical models, we were able to accurately estimate radon concentrations under different conditions of Heating, Ventilating and Air conditioning (HV AC) operations. Various combinations of HV AC operating schemes were tested mathematically. Many possible combinations demonstrate optimal effects.