The air quality in a subway-train was studied to suggest optimal design criteria and operationconditions based on the ventilation demand by passengers. The C02 emitted from thepassengers was the tracer for this study. The C02 bioeffluent from a human body was firstlyquantified and used for the data analysis. Then the C02 concentration was monitored in asubway-train being operated.
The ventilation engineer's plan at the design stage could be influenced by many factors. It may also be different from the requirements for the final users of the spaces. In case of open-space design, which is getting popular due to its flexibility. It is more difficult to provide adequate ventilation to control the indoor air quality. Specially, when partitioning of the space is employed.
Few detailed comparisons of modeled ad measured pollutant concentrations in multizonebuildings have been published. The COMIS air flow and contaminant transport modelpermits simulation of the effects of building and HVAC operation, as well as the influence ofthe local meteorology, on air flows within the building. We have recently used this model tosimulate the release of a gas-phase tracer in a three-story, multi-room building located atDugway Proving Ground, Utah, USA.
The ventilation system of a 60 seats conference room was retrofitted to improve indoor air quality. The old, mixing type installation was replaced by a displacement ventilation system. However, the building layout did not allow an optimum location of air inlets and outlets. It was therefore interesting to measure the actual performance of the new system. Using tracer gas techniques, the age of air was mapped within the room, and the ventilation effectiveness was measured in various configurations. The actual air flow rates were also measured in the ventilation system.
Air change rates, indoor radon and carbon dioxide levels were monitored in a lecture theatre in the Hong Kong University of Science and Technology. Two preliminary measurements (Cases 1 and 2) and one series of demand control ventilation simulation (Case 3) were made to investigate the indoor air quality of the lecture theatre. Radon and carbon dioxide levels were found to be relatively high in Case 1 and later improved at the expense of operating the system catering for maximum occupancy in Case 2.
The air flow in a doorway is governed by density difference caused by temperature difference and pressure difference caused by mechanical ventilation. Tests have been carried out in a unique indoor test house where the room to room to temperature difference could be controlled very accurately with a new control system. In addition to these tests some tests were carried out in a scale model with water as the operating fluid. Two main criteria of unidirectional flow in a doorway have been explored:
A data acquisition system which uses a computer provides a more useful analysis system. Since the processing speed of computer is continuously increasing, the information than it is possible using conventional data acquisition systems. However, the raw measurements also include the signal noise which may lead to difficulty when the signal is analyzed. This work assesses an algorithm for removing possible signal noise, usually with high-frequency, from the measurement of tracer gas concentration.
Login