Evidence based residential ventilation: sizing procedure and system solutions addressed by REHVA Residential Ventilation Task Force

Wider application of heat recovery ventilation in residential buildings brings attention to knowledge and regulatory gaps which call for research and other actions. In many technical questions there is no consensus in national regulations of EU Member States (MS). This applies for instance for air flow rates, i.e. how much ventilation is needed, restrictions of the use of some heat exchangers types, connection of cooker hoods to ventilation system and placement of exhaust air devices. While European standards are well detailed in these aspects for non-residential ventilation, there is very limited information available for residential ventilation systems. Recent European Guidebook REHVA GB No 25 has made an attempt to collect evidence based best practice technical solutions and design principles for residential ventilation. In this paper a recent evidence and common assumptions behind REHVA airflow rate selection procedure is discussed. Best practice solutions and open research questions related to cooker hood connection to heat recovery and compensation to enable balanced operation of ventilation in an airtight building are analyzed. The paper summarizes existing evidence in these questions and defines open research questions for future residential ventilation research agenda.