Evaluation of the effects of ventilation systems on temperature, humidity, air quality and energy consumption in multiple dwellings.

Recently well-insulated and well-airtightened houses are increasing in Japan. Those houses havesome problems of air quality because of formaldehyde from construction materials. Ventilationsystems have possibility to solve these problems. The authors have developed a simulation programfor designing building elements, equipment elements to keep balance among comfortabletemperature and humidity, good air quality and energy conservation. The effects of some ventilationsystems in multiple dwellings are revealed by the developed simdation program. The calculatedresults can be concluded as follows 1) In summer formaldehyde is at high concentrationbecause of high emission rate. 24-hour mechanical ventilation or natural ventilation with largeopening is necessary to keep the concentration low. 2) 24-hour mechanical ventilation systemsrequire 30% more energy consumption than natural ventilation in summer. 3) The program isuseful as a design tool by means of considering comprehensively various effects of factors suchas ventilation.