How to improve air quality at home

Good indoor air is air that’s free from pollutants, damp and mould. The National Institute for Health and Care Excellence (NICE) ¹ recommends that homeowners and renters should keep their homes well-ventilated to reduce damp and condensation and prevent mould; limit their use of gas appliances and solid fuel fires; follow instructions when using candles, paints, glues and solvents, to minimise exposure to pollutants; and choose low emission products where possible.  

According to a study conducted by Professor Jan Sundell in Denmark in 2004², indoor air quality influences humans in several ways:

• Comfort: You can sense the quality of the air the moment you enter a building - if it’s poor, the room quickly becomes uncomfortable to stay in.
• Health: Breathing poor quality indoor air can have negative effects on health.
• Performance: High-quality indoor air can improve mental performance and overall wellbeing.
• Other factors: Clean air flowing indoors feels inviting, reminding us of our connection to nature.

The quality of the air inside your home is influenced by several factors, including ventilation rates, sources of air pollution and environmental conditions.³

An analysis published by Navigant Ecofys in the Healthy Homes Barometer (VELUX, 2017) shows that one in six Europeans live in unhealthy buildings, i.e. damp, overheated buildings with a lack of natural light or inadequate heating.

This analysis also shows that 1.7 times more Europeans say they are in poor health when living in damp homes. Living in a house with a lack of daylight or in adequate heating also leads to 1.5 times more reports of poor health. 

Many of the products we use in our homes can pollute our air. A study conducted by Professor Philomena Bluyssen in 2009⁴, found many compounds in indoor air that can affect health and wellbeing.

These include, volatile organic compounds (VOCs), found in some paints and decorating products; mould and pollen; and chemicals from tobacco smoke, cleaning and personal care products. In most cases, a healthier more natural alternative can be found for these.

To maintain a healthy and comfortable indoor environment, it is important to:

• Minimise the concentration of indoor air pollutants (favour building materials and furniture with low chemical emissions, use low-emission cleaning products and manage humidity)
• Monitor levels of CO₂, humidity, VOCs and other indoor air pollutants.  

Carbon dioxide (CO₂) levels in your home are a good indicator of how well it’s ventilated.

As CO₂ is emitted by respiration and by some household appliances, an accumulation can indicate poor ventilation. This can, in turn, exacerbate the effects of other pollutants in the air.

High concentrations of CO₂ could lead to symptoms such as drowsiness, headaches and decreased productivity.

Natural ventilation is an effective way to reduce CO₂ levels in an indoor space. Accumulated carbon dioxide can be diluted and reduced by exchanging air with the outdoors.

Carbon monoxide (CO) is a colourless, odourless and toxic gas that poses a significant risk to indoor air quality and human health. It is primarily produced by the incomplete combustion of fuels in gas appliances. Exposure to elevated levels of carbon monoxide can cause symptoms such as headaches, dizziness, nausea and, in extreme cases, death. 

Poor indoor air quality and indoor air pollution resulting from carbon monoxide is often linked to inadequate ventilation or malfunctioning appliances. It is essential to ensure proper ventilation, regularly check gas appliances and to fit carbon monoxide detectors in your home.

Natural ventilation helps maintain healthy indoor air. Strategically placing windows in a building can maximise the effectiveness of natural ventilation.

Installing roof windows, in addition to vertical windows, creates upward air currents through rooms. This improves air renewal and the removal of indoor pollutants, such as volatile organic compounds (VOCs), fine particles and other pollutants generated indoors.

This cross-ventilation approach is particularly effective in rooms with high indoor air pollution levels or in areas of high humidity, such as kitchens and bathrooms.

To combat the immediate effects of poor air quality and minimise long-term risks, take these five steps:

Natural ventilation is one of the most direct and effective ways to improve the indoor air quality of your home.

Open windows, especially roof windows, regularly to introduce fresh outdoor air and dilute the concentration of indoor air pollutants.

Using extractor fans in places like the kitchen and bathroom is an easy way to clear out cooking odours and excess moisture while bringing in fresh air.

Air purifiers, such as HEPA (High Efficiency Particulate Air) filters remove particles and microorganisms from indoor air.

These systems remove particles like pollen, pet dander, and smoke, helping you breathe cleaner, healthier air at home.

Choose building materials that give off little to no harmful chemicals. Keep your gas boiler and other fuel-burning appliances well maintained to avoid dangerous leaks.

Try to keep your home’s humidity between 40% and 60% - this helps stop mould and dust mites from spreading.

Keeping your home clean with frequent vacuuming and cleaning of surfaces can also help improve the quality of the air in your home.

And it’s important to use less toxic or non-toxic decorating and cleaning products to reduce the presence of dangerous chemicals in your indoor air.

A healthier home doesn’t have to be complicated - it starts with clean, fresh air. Breathe well, live well, and let your home truly support your wellbeing.