indoor air quality

To reduce the carbon footprint of the built environment, a significant overhaul of the existing housing stock is essential. This entails not only ensuring proper insulation and airtightness in residences but also optimizing their ventilation systems. To precisely gauge the impact of an advanced ventilation system, the use of a pressure node model, such as multizone ventilation models like COMIS or TNO's AirMAPs model, is indispensable. However, when dealing with existing dwellings, numerous unknown variables, including interior door usage, can introduce substantial variations in results.

Achieving energy-efficient dwellings has become a vital part of the global climate action plan to reduce energy usage and carbon emissions. Deep energy retrofits (DER) can help reduce residential energy use significantly. However, evidence on how DER impacts on indoor air quality (IAQ), and consequently, occupant health, is scarce. More in-depth analysis of IAQ data before and after energy retrofits is essential to understand the indoor environmental challenges of adopting energy efficiency measures.

Indoor air pollution can pose a serious threat to human health and can increase the risk of early mortality. Studies have shown that human exposure to indoor pollution is more common than to outdoor pollution, especially where people spend the majority of their time indoors at home. Heating, ventilating, and air conditioning (HVAC) systems are used in buildings to regulate internal climate to improve the comfort level for occupants. In addition, ventilation rates are often increased to maintain appropriate Indoor Air Quality (IAQ).

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 COVID-19 pandemic increased the awareness and importance of infectious pathogens as contaminant in the indoor air, especially for non-residential buildings with a high occupational density like schools. During the COVID-19 pandemic air cleaning is often proposed as mitigation strategy for infectious risk in these types of buildings. However, indoor air quality (IAQ) in general comprises of a large range of possible contaminants and factors that can equally impact the health, comfort and well-being of occupants.

Personalized Environmental Control Systems (PECS) have advantages of controlling the localized environment at occupants’ workstation by their preference instead of conditioning an entire room. A new IEA EBC Annex (Annex 87 - Energy and Indoor Environmental Quality Performance of Personalised Environmental Control Systems) has recently started to establish design criteria and operation guidelines for PECS and to quantify their benefits. This topical session will provide an introduction to the objective/scope, activities, and intended outputs of the annex.

The scientific community has been aware of the importance of indoor air quality (IAQ) for many decades, but the COVID-19 pandemic has brought a significantly higher level of attention from the general public and governmental entities to this theme. However, IAQ comprises hundreds of other parameters besides infectious pathogens, many of which can equally impact the health, comfort and well-being of occupants.

Most New Zealand schools are designed to be naturally ventilated, using openable windows (Ministry of Education Design Quality Standard Guidelines). Furthermore, they must meet the New Zealand Building Code Clause G4 - Ventilation. Clause G4 requires the “net openable area of windows in a classroom to be no less than 5% of the combined habitable floor area to achieve sufficient ventilation”. Although they are designed to code, there is no end-user operational or systems requirement for them to be opened.

Smart ventilation which provides air renewal thanks to its variable airflows adjusted on the needs can improve both indoor air quality (IAQ) and energy performance of buildings. However, such performance gains should be quantified with performance-based approaches. In this paper, we propose to extend the performance-based approach with a robust methodology to rank the ventilation systems performance. Such a methodology could be used in a decision-making tool at the design stage of buildings.

Metal Oxide Semiconductor (MOS) sensors measuring Volatile Organic Compounds (VOC) seem to be an obvious step towards broadly available Demand Controlled Ventilation (DCV). The previous research shows that MOS VOC sensors can detect high pollution events such as cleaning, painting, or high occupation density. These abilities seem to make MOS VOC sensors suitable to complement ventilation control systems, especially concerning residential ventilation.