literature review

The offer of air cleaners has increased significantly since the SARS-CoV-2 pandemic. However, it is not clear to what extent they can contribute to indoor air quality. There are multiple standards that describe test methods for air cleaners, but no consensus can be found on how to determine the performance of the air cleaners.

The main task of every ventilation system is to dilute and extract pollutants from indoor air, most importantly in occupied space. This is usually achieved by exchanging polluted indoor air with less polluted outdoor air. In the case of a mechanical ventilation system, this process requires a fan power to be provided which is approximately proportional to the power of three to the resulting airflow. Because of this, reducing the necessary airflow to be provided by the ventilation unit e.g., by 10% would lead to a reduced power supply of about 27%.

This work is part of two French research projects “Durabilit'air1” (2016-2019) and “Durabilit'air2” (2021-2024), that aim at improving our knowledge on the variation of buildings envelope airtightness through onsite measurement and accelerated ageing in laboratory-controlled conditions.   
During a past AIVC conference, a publication of the Durabilit’air1 project has presented and discussed an experimental protocol for characterizing assembly of products for buildings’ airtightness in laboratory controlled conditions.   

The content presented comes from the Technical Note (TN) 71 “Durability of building airtightness” published on Airbase, the AIVC bibliographic database.

The content presented comes from the Technical Note (TN) 71 “Durability of building airtightness” published on Airbase, the AIVC bibliographic database.

The content presented comes from the Technical Note (TN) 71 “Durability of building airtightness” published on Airbase, the AIVC bibliographic database.

Mandatory building airtightness testing has come gradually into force in European countries mostly because of the increasing weight of building leakage energy impact on the overall energy performance of low-energy buildings. Therefore, airtightness level of new buildings has significantly improved in the last decade.
However, until now, low expertise is available about the durability of building airtightness at mid- and long-term scales.

The paper at hand collects research findings on the impact of air flow on the thermal performance of pitched roof assemblies. Air flows in these components are typically a mixture of: 1) in/exfiltration, 2) natural convection and 3) wind-washing. In the current building practice the necessity of an air barrier to guarantee the thermal and hygric performance of roofs is well established. Yet the need for a continuous wind barrier to avoid wind-washing of the insulation layer is still often underestimated in practice.

A working group for natural ventilation and cross-ventilation at the Architectural Institute of Japan (AIJ) was established in 2005 by researchers and designers with an interest in this topic. One of the tasks of the working group is to review and classify related research papers. This paper introduces the activities of the working group and presents some results of the review work.

A multidisciplinary panel of experts in the EUROVEN collaboration evaluated scientific literature on the effects of ventilation on health, comfort and productivity in non-industrial indoor environments. Fourteen papers of the 105 reviewed were judged to provide background information relevant to the objective, and thirty papers were judged conclusive. The group drew their conclusions based on these thirty papers. They agreed that ventilation is strongly associated with comfort and health, and that an association between ventilation and productivity is possible.