18-19 May 2023, Workshop, Tokyo, “Towards high quality, low-carbon ventilation in airtight buildings”

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.

Programme

Organisers

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).

Venue

The workshop took place at Bellesalle Mita Garden.