Ventilation reliability - an evaluation tool for domestic ventilation.

Pre-assessing the reliability of ventilation systems is a dificult task and no simple methodshave existed. This paper presents a tool for estimating the reliability of domestic ventilationsystems. In general, ventilation reliability means the probability that the chosen ventilationsystem performs in an acceptable way for a certain building, in a certain climate, betweenscheduled maintenance measures. The tool presented consists of two different sub-tools: onefor reliability as indicated by air flow rate stability as a function of situational factors andanother for reliability as indicated by performance over time i. e. systems and componentsreliability.Four different ventilation strategies have been analysed; natural window airing, passive stackventilation, mechanical exhaust ventilation and mechanical exhaust and supply ventilation.The use of the tool involves specifications of the dwelling, the occupancy, the ventilationsystem etc. and the tool presents the consequences of the choices made, in a qualitative wayon a five-grade scale from excellent to very bad reliability.