Methodology for assessing the air-exchange performance of residential ventilation systems

Residential ventilation standards, especially in Europe are slowly but substantially moving away from their usual prescriptive approach towards performance based specifications. While academics and policy makers argue about the relevant IAQ indicators, housing developers and end users need to make a choice between the different ventilation system options they are faced with in the market. Although several IAQ rating systems have emerged, a comprehensive assessment method to rate the inherent qualities of the ventilation system itself is not available [6]. In this paper, we propose a methodology for such a rating system based on the ability of the system to deliver the requested amount of air at the right place and time, issued from a project commissioned by the European Ventilation Industry Association (EVIA). The proposed method makes a distinction between the performance in habitable and wet spaces in dwellings and includes technical aspects such as mechanical support of the airflow, automatic control and (where applicable) filtration. The label proposed to communicate the results of the assessment specifies the design flow rate, the performance in each of the space types and a filtration rating separately, allowing end users to objectively compare products that are suited for their particular needs rather than lumping these aspects together in a rating for the ‘average’ dwelling. This paper is intended as a solicitation of comments from the broader field of ventilation stakeholders on the fundamental structure of the rating system.