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

Jarek Kurnitski,Harry Van Weele,Thomas Carlsson,Olli Seppänen,Petra Vladykova Bednarova,Martin Thalfeldt,Macit Toksoy,S.I Tanabe,H Zhang,P Wargocki,I Nastase,L Mazzarela,C Inard,M.C Gameiro Da Silva,J Kurnitski,G Cao

doi:10.1051/e3sconf/201911101016

Abstract

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.

Highlights

Energy performance of buildings has been continuously and systematically improved in Europe with step of transition to nearly zero energy buildings (NZEB) in 2019-2021
While European standards are well detailed in these aspects for non-residential ventilation, there is very limited information available for residential ventilation systems
Still huge research need remains, experience of the use of advanced ventilation systems is needed for further development of components, system solutions, control and operation strategies as well as proper sizing

Summary

Introduction

Energy performance of buildings has been continuously and systematically improved in Europe with step of transition to nearly zero energy buildings (NZEB) in 2019-2021. In the recent review process of Energy Performance of Buildings Directive (EPBD), the assessment of the implementation status of the EPBD by the EU MS in terms of ventilation and indoor air quality criteria was conducted by European Commission Joint Research Center [2] This assessment confirmed that there still exist MS without binding ventilation requirements and many inadequate ventilation problems have been reported especially from renovations, where insulation, improvement of air tightness and replacement of windows has often stopped air change because adequate ventilation. The scientific literature review done by JRC [2] provided new evidence that mechanical heat recovery ventilation systems have led to an overall improvement of the IAQ and reduction of reported comfort and health related problems if properly designed and operated This reveals that highly performing and healthy buildings do exist in EU and have improved occupant comfort and satisfaction. Still huge research need remains, experience of the use of advanced ventilation systems is needed for further development of components, system solutions, control and operation strategies as well as proper sizing

Existing evidence on ventilation need in dwellings

Room-based air flow rates for design of ventilation

Ventilation system solutions for new low energy dwellings

Findings

Conclusions