News & Events

Indoor Air Quality Research Centre of New Zealand calls for government prioritisation on ventilation this World Ventil8 Day

As the world faces the challenge of maintaining healthy indoor environments in an era of pandemics and climate change, World Ventil8 Day 2024 is set to spotlight the critical role of ventilation in enhancing health and wellbeing. This year’s theme “Enabling Action” emphasises the need for proactive measures to improve building ventilation to ensure healthier indoor environments for everyone.

Good ventilation is not just about being comfortable; it is essential for healthy living. Opening windows and doors brings in fresh air when the outdoor conditions are clean, while using bathroom extraction fans and kitchen range hoods is important for removing potential pollutants. Studies have shown that effective ventilation can significantly reduce the risk of respiratory infections, improve sleep quality, and enhance overall productivity. Despite these benefits, millions of people worldwide continue to suffer from the effects of inadequate ventilation and household air pollution, leading globally to over three million premature deaths each year¹.

Importance of home ventilation for healthy living

A BRANZ study², published in 2023, undertaken in partnership with Stats NZ and the Ministry of Business, Innovation and Employment highlighted the importance of healthy housing behaviours. This included using mechanical ventilation, opening windows in the bathroom or kitchen while cooking, and using heating in living areas and bedrooms during winter. The study surveyed over 830 households, consisting of approximately 500 owner-occupied and 330 non-owner-occupied houses. It found that the household group most likely to report airing out bedrooms, bathrooms, and kitchens every time they were used had the least presence of moderate or worse visible mould in living areas and bedrooms, compared to households overall (30% compared to 40%).

A University of Otago study³, published in 2024 and funded by the Building Research Levy, explored previously collected data from 450 Wellington households, to examine mould levels, temperature and relative humidity in relation to ventilation behaviour patterns. Opening windows daily during summer was common, while ventilating bedrooms during winter was much less frequent. A daily pattern of opening bedroom windows in winter was associated with a reduced amount of visible mould compared to rarely or never opening the windows. Interestingly, frequency of bathroom ventilation was not associated with mould levels in bedrooms, highlighting the importance of ventilating all areas of a home.

BRANZ research⁴ recommends aiming for a moderate level of airtightness in combination with mechanical ventilation for new builds as a means to achieve reliable indoor air quality. Incorporating the same measures as existing stock is renewed or replaced will have a significant impact in reducing mould and moisture complaints.

Improving ventilation in Aotearoa’s public buildings

Inadequate ventilation has also been noted in public buildings. A 2024 Ministry of Health’s note⁵ to the Minister “Options to improve ventilation”, underscores the importance of improving ventilation in New Zealand buildings. It highlights that many public buildings in New Zealand are not well-ventilated, which increases the risk of transmission of airborne pathogens. Improving ventilation can reduce the risk of transmission of diseases such as COVID-19, measles, and influenza, improve cognitive function and reduce exposure to pollutants associated with chronic respiratory conditions. There are simple measures that can often improve ventilation without significant additional costs. For example, opening windows and doors can significantly reduce CO₂ levels and improve air quality in schools and early childhood education centres. Additionally, using mechanical ventilation and air purifiers can further enhance indoor air quality, especially in buildings where natural ventilation is not feasible.

A recently released report⁶, “Time to clear the air,” commissioned by the Facilities Management Association of New Zealand (FMANZ), estimates that improving ventilation in New Zealand’s offices and schools could deliver economic benefits between $776 million and $1.15 billion over a 10-year period. This includes reducing sickness and improving productivity, with potential annual benefits of up to $80.1 million from reduced sickness in offices alone. The report also highlights that poor indoor air quality is a hidden cost to people and businesses, contributing to the transmission of illnesses and reduced productivity. By raising ventilation standards and ensuring compliance, significant health and economic benefits can be achieved, justifying the investment in better ventilation systems.

A call to action on ventilation research and behaviour change for improved wellbeing

In New Zealand, we have a series of environmental reports⁷ produced by the Ministry for the Environment and Stats NZ highlights the significant impact air quality has on the health of New Zealanders. However, we lack data to quantify the economic and health benefits of increasing effective ventilation and improving indoor air quality in residential households. While we are continually learning more about how inadequate ventilation and poor air quality affect our health and the economy, we still need to put in more effort to raise awareness about their impact.

On World Ventil8 Day, we call on the government to establish research priorities in ventilation, indoor air quality and indoor environmental quality for residential dwellings. We recommend new residential buildings achieve a moderate level of airtightness and include mechanical ventilation. We also encourage individuals to adopt healthy home behaviours, such as opening windows and doors to bring in fresh air when outdoor conditions are clean and using bathroom extraction fans and kitchen range hoods to remove potential pollutants. By prioritising ventilation, we can create healthier indoor environments and protect the wellbeing of our communities.

References

1. WHO (2024) Household air pollution
2. BRANZ (2023) SR482 Housing condition and occupant wellbeing: Findings from the Pilot Housing Survey and General Social Survey 2018/19
3. BRANZ (2024) ER90 Natural ventilation in damp homes – a qualitative exploration of behaviours and interventions for change
4. BRANZ (2020) SR455 Airtightness of selected apartments in New Zealand
5. Ministry of Health (2024) Health Report to the Minister: Options to improve ventilation
6. Facilities Management Association of New Zealand (2024) Time to clear the air: The economic benefits of improving New Zealand’s indoor air quality
7. Ministry for the Environment & Stats NZ (2024) New Zealand’s Environmental Reporting Series: Our air 2024 | Tō tātou hau takiwā

About the IAQRC

The Indoor Air Quality Research Centre of New Zealand (IAQRC) brings together expertise from leading research organisations and includes experts in building science, public health and air quality. The IAQRC is currently made up of members from BRANZ, GNS Science, Massey University, the Air Quality Collective, University of Canterbury, University of Otago and Victoria University of Wellington. The IAQRC aims to increase awareness of indoor pollutants, and related health outcomes, and to advocate for improved indoor air quality. More at https://iaq.org.nz/

About World Ventil8 Day 2024

Taking place every year on 8 November, World Ventil8 Day aims to raise awareness of the importance of ventilation as a crucial part of enabling health and wellbeing of people. It also seeks to recognise and celebrate the ventilation and indoor air quality community. More at https://www.worldventil8day.com/.