18-19 May 2023, Workshop, Tokyo, “Towards high quality, low-carbon ventilation in airtight buildings”
18 - 19 May 2023 | Tokyo, Japan
Bellesalle Mita Garden
09:00 Europe/Brussels

NILIM and BRI of Japan, together with the Air Infiltration and Ventilation Centre (AIVC) organised a workshop entitled “Towards high quality, low-carbon ventilation in airtight buildings" held on 18-19 May 2023 in Tokyo, Japan.

The 2-day workshop provided the opportunity to Japanese researchers and engineers, as well as international experts visiting Japan, to present and discuss recent developments in relation to ventilation and airtightness. The workshop was organized in 5 thematic sessions.

In the opening session, a representative of the ministry in charge of Japanese policies toward zero carbon buildings in 2030 and 2050 described the latest concrete policy measures including energy efficiency. Latest evolutions in regulations and standards on energy performance and ventilation in Europe and the US were also presented.

In the session for IEA EBC Annexes (international collaborative R&D projects), which are relevant to ventilation, latest outputs from 1) technologies for gas-phase air cleaning (Annex 78), 2) side-by-side management methods of indoor air quality and energy efficiency (Annex 86) and 3) personalized environmental control system technologies (Annex 87) were presented.

An airtight building envelope is essential especially in order to avoid heat loss due to air leakages. In non-residential buildings, in addition to wind and stack effects, air pressure caused by HVAC systems may worsen the heat loss due to the air leakages. However, it seems that effective techniques for improving the airtightness in non-residential buildings have not yet been shared enough among Japanese building engineers and researchers. Some existing approaches in Europe, North America and Japan and future perspectives for standardisation were discussed in the airtightness session.

In the session on approaches to search for more energy efficient and reliable ventilation systems, the latest standards for testing heat recovery effectiveness in laboratories were reviewed with test examples, in which key characteristics of products influential on the actual effectiveness were demonstrated. Characteristics of the Japanese market of energy recovery ventilators and improvements in the latest products were analyzed. Performance assessment of other energy efficient ventilation strategies and smart ventilation were also discussed.

In the session on the role of ventilation in infection control, a Japanese government proposal in July 2022 on effective ventilation to avoid infections by large aerosol and small floating aerosol diffusion was reviewed with some actual infection case studies. Also, the characteristics of aerosol transmission route of respiratory pathogens and their mitigation strategies were discussed by building physics researchers, who have been collaborating with medical experts in the committee dedicated to the Japanese infection control strategies. Other presentations discussed new developments in ventilation standards and regulations, and advances in measurement techniques.


Day 1 – Thursday May 18th 2023   


Chairs: Takao Sawachi (BRI), Peter Wouters (INIVE) 

09:00Welcome on behalf of NILIMTakahiko Hasegawa (Deputy Director-General, NILIM, JP)  mp4
09:10Welcome on behalf of BRI and overview of IEA-EBCTakao Sawachi (EBC Executive Committee Chair, JP  mp4
09:20Overview of AIVC, TightVent, venticool & IEQ-GAArnold Janssens (AIVC Operating Agent/INIVE/UGent, BE) PPTmp4
09:30Japan’s Policy toward Carbon Neutrality in the Housing and Building SectorsTakashi Imamura (Housing Bureau-MLIT, JP)AbstractPPTmp4
09:55Context and policies for energy and ventilation in Europe, new evolutions in EPBDJaap Hogeling (EPB/REHVA/ISSO, NL)AbstractPPTmp4
10:20Ventilation standards in the USIain Walker (LBNL, USA)AbstractPPTmp4

IEA-EBC Annexes

Chairs: Hilde Breesch (KU Leuven), Kazuhide Ito (Kyushu University)

11:15A general overview of IEA-EBC Annex 78: Supplementing ventilation with gas-phase air cleaning, implementation and energy implicationsPawel Wargocki (DTU, DK)AbstractPPTmp4
11:30International standardization of testing perceived air quality and the supporting information from in silico model for transport efficiency of acetone from indoor to olfactory epithelium cellsKazuhide Ito (Kyushu University, JP)AbstractPPTmp4
11:55An update on IEA-EBC Annex 86: Energy efficient smart IAQ management in residential buildingsJelle Laverge (UGent, BE)AbstractPPTmp4
12:10Dallying with DALYs: a harm-based approach to IAQ acceptabilityBenjamin Jones (Nottingham University, UK)AbstractPPTmp4
12:35Lunch Break   
13:35IEA-EBC Annex 87: Energy and indoor environmental quality Performance of Personalised Environmental Control Systems (PECS)Bjarne Olesen (DTU, DK)AbstractPPTmp4
13:50Personal environment comfort system (PECS) for improving thermal comfort and IAQ in a zero energy buildingShin-ichi Tanabe (Waseda University, JP)AbstractPPTmp4

Quality assurance of ventilation and heat recovery systems

Chairs: Alireza Afshari (Aalborg University), Masaki Tajima (Toyohashi University of Technology)

14:35Actual effectiveness of energy/heat recovery ventilators in buildings: how is it influenced by key design factors and testing results (airflow, airflow ratio, unit exhaust air transfer ratio)?Tetsutoshi Kan (Better Living, JP)AbstractPPTmp4
15:00Latest trends and technologies of energy recovery ventilators in JapanJunichi Takahashi (Mitsubishi Electric co, JP)AbstractPPTmp4
15:55Performance assessment framework for smart ventilation systemsHilde Breesch (KULeuven, BE)AbstractPPTmp4
16:20Effect of indoor temperature differences and zoning on the performance of energy efficient ventilation strategies for domestic buildingsJelle Laverge (UGent, BE)AbstractPPTmp4
17:05End of Day 1   
Day 2 – Friday May 19th 2023   


Chairs: Yu Wang (Branz), Hiroshi Yoshino (Tohoku University)

09:00Proposal to promote airtightness in non-residential buildings in JapanKiyoshi Hiwatashi (Taisei Corporation, JP)AbstractPPTmp4
09:25Trends in building and ductwork airtightness in different countriesValérie Leprince (Cerema, FR)AbstractPPTmp4
09:50Airtightness testing of large buildingsIain Walker (LBNL, USA)AbstractPPTmp4
10:15Measurement for exterior wall airtightness of high-rise buildings using stack effect/individual air conditioning and outdoor air entering through entrance doorsYuichi Takemasa (Kajima Technical Research Institute, JP)AbstractPPTmp4
11:10Airtightness of large buildings in Japan: current situation and a proposal for the futureTakashi Hasegawa (Eikan-Shoji, JP)AbstractPPTmp4
11:35ISO 9972: An overview of difficulties with the current standardBenedikt Koelsch (Cerema, FR)AbstractPPTmp4
12:00Durability of building airtightnessValérie Leprince (Cerema, FR)AbstractPPTmp4
12:45Lunch Break   

Role of ventilation in infection control

Chairs: Valérie Leprince (Cerema), U Yanagi (Kogakuin University)

13:45Aerosol transmission route of respiratory pathogens and their mitigation strategiesU. Yanagi (Kogakuin University, JP)AbstractPPTmp4
14:10Countermeasures against indoor aerosol infection in JapanMotoya Hayashi (Hokkaido University, JP)AbstractPPTmp4
14:35Using pathogen-free air to reduce infection risks in buildings (pre-recorded presentation)Chris Iddon, (UCL, UK)AbstractPPTmp4
15:00Revision of ISO17772-1 and EN16798-1 Standards dealing with indoor environmental qualityBjarne Olesen (DTU, DK)AbstractPPTmp4
15:55Role of air cleaning in infection controlPawel Wargocki (DTU, DK)AbstractPPTmp4
16:20Developing regulations to improve IAQ and ventilation in Belgian buildingsPeter Wouters (INIVE, BE) and Arnold Janssens (UGent, BE)AbstractPPTmp4
16:45Airtightness and internal air flows in multifamily buildingsIain Walker (LBNL, USA)AbstractPPTmp4
17:10Discussion  mp4
17:45End of Day 2   


The workshop was organized by NILIM and BRI together with the Air Infiltration and Ventilation Centre (AIVC) and facilitated by INIVE (International Network for Information on Ventilation and Energy Performance).


The workshop took place at Bellesalle Mita Garden.