How to improve your home’s ventilation

Having good ventilation in your home is important because it:

• Improves air quality.
• Lowers the risk of condensation, damp and mould.
• Protects the building from structural problems caused by damp and rot.
• Lowers the amount of pollution in the air.
• Lowers the risk of respiratory problems such as asthma.

Ventilation is important in every home. And it’s even more important if your home has energy efficient upgrades such as:

• insulation
• sealed doors and windows
• draught proofing

These substances can be harmful depending on how much of them there are in your home:

These are some signs that your home needs better ventilation. But it’s worth remembering that many pollutants don’t give off any noticeable signs like colour or smell. So, just because you can’t see or smell a problem, doesn’t necessarily mean your home has good air quality.

Signs your home needs better ventilation include:

• Ongoing condensation problems.
• Problems with mould.
• Strong smells that take a long time to go away.
• High readings from moisture and air quality monitors.

Here are the main types of ventilation:

• Opening doors and windows to let air circulate naturally.
• Using trickle vents and wall vents to let in small, controlled amounts of air.
• Intermittent extract ventilation: Bathroom extractor fans and cooker hoods that you can switch on and off to extract air while bathing or cooking.
• Continuous extract ventilation: Mechanical ventilation systems that continuously extracts air from the home.
• Heat recovery ventilation: Continuous extraction systems that uses the heat of the extracted air to pre warm the fresh, incoming air.

You should also have gaps underneath your internal doors let air circulate around your home. The gap should be 10mm between the bottom of the door and the top of the carpet or flooring.

Here’s how you can manually improve your home’s ventilation:

• Keep your trickle vents open all the time.
• Use extractors when cooking or washing.
• Keep a window open when using a wood burner or open fire.
• Open windows to boost ventilation.

These recommendations might not apply if you already have a mechanical ventilation system in your home that supplies and extracts air continuously. Check the instructions for the system or speak to your installer.

Ventilation is just as important in winter as it is in summer. You should keep trickle vents open all year round, even during the colder months. If you close them to stop cold air coming in, make sure you open them up again as soon as you can.

You should also open windows at least two or three times a day for at least five minutes, even in cold weather. Aim to open a few windows at the same time on different sides of the building.

While it’s true that some warm air will escape outside while you do this, most of the heat is stored in the structure of the house itself. The air in your home should quickly warm up again once you’ve closed the windows, so don’t worry about losing too much heat.

To minimise losing heat, prioritise opening windows on the sunnier side of the house. This lets in air that might be warmer than the shady side.

Both home insulation and draught proofing are designed to make the house more ‘airtight’. This means that it’s harder for heat to escape the building, and stops unwanted air coming in.

Draughts may bring cold air through gaps and cracks in the walls, floors, around older doors and windows. But many homes are already fairly well draught proofed. In this case, trying to ‘plug every gap’ may actually lead to poor air quality where moisture and indoor pollutants could rise to harmful levels.

Draughts often make you feel cold because they often bring cold air in at floor level. Ventilation, however, is designed to avoid this by bringing in air at higher levels. This is why trickle vents are usually at the top of windows. Good ventilation will distribute fresh air around the house, improving air quality throughout and avoiding causing a cold draught around your feet.

So insulation or draught proofing improvements need to be accompanied with proper ventilation to make sure that fresh air can come into the house.

When installing any kind of insulation or draught proofing, speak to the installer about what ventilation measures they’re considering as part of the design.

You can improve your home’s air quality by:

• Reducing sources of pollution in the home.
• Getting an air quality monitor.
• Using a dehumidifier.
• Switching to an electric cooker.
• Using an air purifier.

It’s well known that plants absorb and release CO₂ as part of their natural processes. This can help improve your carbon footprint a small amount. But plants can also help lower indoor air pollution levels, particularly NO₂.

You’d need a lot of plants to make any noticeable difference in your home’s levels of CO₂. And, since plants can increase moisture in the air, it could lead to dampness in the home. But having some greenery in the home can still help boost your overall wellbeing.

If you’re renting your home, speak to your landlord in the first instance. This is especially important if you’re dealing with problems with damp or mould.

For mechanical ventilation systems, speak to a ventilation specialist. For extractors and cooking extractors, speak to an electrician.

Trickle vents must be fitted to new windows as part of Building Regulations, so speak to a window installer for more information.

Adding a trickle vent to an existing window risks damaging the window and frame. Instead, consider speaking to a ventilation specialist to install a wall vent.

For all installation work, we recommend getting quotes from at least three installers who are certified with TrustMark – a government-endorsed quality scheme.

If you’re having any energy saving improvements done to your home, ask the installer about what ventilation measures they plan on adding.

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