Outline of ventilation standard for acceptable indoor air quality, SHASE Japan.

The Ventilation Standard HASS-102 of The Society of Heating, Air-conditioning andSanitary Engineere of Japan (SHASE Japan) was revised in November, 1997. The title of therevised standard is Ventilation Standard for Acceptable Indoor Air Quality. So far, the oldVentilation Standard, which was issued in 1939, had been used for a long time. The task forrevision was undertaken by the Sub-committee on Ventilation Effectiveness and Standard(chaired by Murakami) of SHASE Japan. This paper focuses on the frame work of theStandard, design criteria for acceptable concentration of indoor air pollutants, calculationmethod for ventilation requirement, technical principles for construction of ventilationequipment and so on.Main points for revision are as follows;1) The amount of ventilation requirement is obtained by the emission rate and the designcriteria for acceptable concentration of indoor air pollutants. In other words, the amount ofventilation requirement is calculated in consideration of the situation of space usage andthe conditions of air pollutant generation.2) The kinds of indoor air pollutant prescribed for in this standard are CO2, CO, suspendedparticulate, NOz, SO2, HCHO, radon, asbestos and TVOC.3) Design criteria for acceptable concentration of CO2 is provided by a general indoor qualityindex (1000ppm) as well as one of pollutant8 influencing occupant's health (3600ppm). Itdescribes how to properly use these two indexes for each pollutant source.4) When pollutants are not perfectly mixed with the room air, ventilation effectiveness istaken into account for calculation of the amount of ventilation requirement.5) Also prescribed are technical principles for construction of ventilation equipment and testmethods of ventilation performance after the construction.