indoor air quality

The association between indoor air quality (IAQ) and sleep quality was investigated in this study. A total of 27 participants (14 males and 13 females, 20-33 yrs.) without any sleep disorders and chronic diseases were recruited and divided into two groups: a polysomnography (PSG) group and a non-PSG group. The IAQ was changed by opening or closing windows. There were two phases for the experiment and two nights in each phase including one adaptive night and one test night, and around one-week washout period between two phases.

More than 20 years of one’s life is spent in the bedroom when sleeping. Sleep quality is essential for our health, well-being and next-day performance. However, there is very little information on how bedroom air quality affects the quality of sleep. One of the reason could be that the accurate measurements of the quality of sleep have been the domain of sleep research groups and sleep laboratories using polysomnography. In the recent years, however, many low-cost sleep monitors and actigraphs made their way into the market.

Within the ventilation principle of buildings, the outdoor air is considered as a source of fresh, "clean" air. Outdoor air quality monitoring by environmental agencies, academic research projects and a broad range of citizen science projects show that this is not always the case. Although the outdoor air quality in our cities already improved, the concentrations of certain pollutants, especially particulate matter and peak pollutions of ozone (and its precursors nitrogen oxides and volatile organic compounds), remain problematic.

Combustion appliances are used in many buildings to provide space heating and domestic hot water. These appliances emit smoke that contains pollutants that must be kept away from the ventilation air supply of the building, to limit their impact on the indoor air quality (IAQ). An efficient way to prevent those pollutants from entering the ventilation circuit is to place the chimney terminal above the top of the roof, as far as possible from the air supply openings.

Indoor carbon dioxide (CO2) concentrations have been used for decades to evaluate indoor air quality (IAQ) and ventilation. However, many of these applications reflect a lack of understanding of the connection between indoor CO2, ventilation rates and IAQ. In particular, a concentration of 1800 mg/m3 (1000 ppmv) has been used as a metric of IAQ and ventilation without an appreciation of its basis or application.

Cooking is one of the most substantial sources of indoor air pollution in most residences.  This is mitigated most often by exhaust devices located near cooking surfaces.  In this study, we measured the efficacy of one type of kitchen ventilation device: an island overhead kitchen exhaust.  Laboratory tests using tracer gas capture were performed on a full-scale mock-up of a kitchen with a cooktop in an island. The results show that the Capture Efficiency (CE) varies greatly from about 10% to nearly 100%.

This article proposes to study the impact of envelope and internal partition walls airleakage distributions, on the indoor air quality (IAQ) performance. It is based on a preliminary performance-based approach using formaldehyde with three emission levels (low, medium, high). This multizone modelling (CONTAM) approach uses as performance indicators, the average concentration per room as well as the percentage of time of exceeding the limit value (ELV) of 9 µg.m-3.

Ventilation is critical in interpreting indoor air quality (IAQ), yet few IAQ assessments report ventilation rates; even when they do, the measurement method is often not fully described. Most ventilation assessments use a tracer gas test (TGT) to measure total air change rate. In a TGT, the indoor air is marked with an easily identifiable gas (tracer) so that the air exchange rate can be inferred by monitoring the tracer’s injection rate and concentration.

Occupants in non-industrial indoor environments should decide whether the indoor air quality is acceptable or not. This paper describes the method by which the assessments of acceptability of air quality can be used for measuring short-term sensory effects on humans caused by indoor exposures. It also describes how this method can be applied to estimate the perceived indoor air quality used as a design criteria for the ventilation of buildings.

The proposed Annex should bring researchers and industry together to investigate the possible energy benefits by using gas phase air cleaners (partial substitute for ventilation) and establish procedures for improving indoor air quality or reduced amount of ventilation by gas phase air cleaning. The project shall also establish a test method for air cleaners that considers the influence on the perceived air quality and substances in the indoor air.