Word on Health

Word on Ventilation for Health

We are grateful to Professor Peter Howarth, Professor of Allergy and Respiratory Medicine at Southampton University for his input to our radio report which you can hear again further down this page anf to the UK government and NHS Direct for the use of the support information below.

According to the UK Government, ventilation is the process of introducing fresh air into indoor spaces while removing stale air. Letting fresh air into indoor spaces can help remove air that contains virus particles and prevent the spread of coronavirus (COVID-19).

When someone with COVID-19 breathes, speaks, coughs or sneezes, they release particles (droplets and aerosols) containing the virus that causes COVID-19. While larger droplets fall quickly to the ground, aerosols containing the virus can remain suspended in the air. If someone breathes in virus particles that are suspended in the air, they can become infected with COVID-19. This is known as airborne transmission.

In poorly ventilated rooms the amount of virus in the air can build up, increasing the risk of spreading COVID-19, especially if there are lots of infected people in the room. The virus can also remain in the air after an infected person has left.

Bringing fresh air into a room and removing older stale air that contains virus particles reduces the chance of spreading COVID-19. The more fresh air that is brought inside, the quicker any airborne virus will be removed from the room.

Ventilation is most important if someone in your household has COVID-19 or if you are indoors with people you do not live with. You can pass COVID-19 on to others if you only have mild symptoms or even no symptoms at all.

Good ventilation has also been linked to health benefits such as better sleep and fewer sick days off from work or school.

Ventilation does not prevent COVID-19 from spreading through close contact and is only one of the actions you can take to stay safe and help prevent the spread of COVID-19.

Minimise the amount of time you spend indoors with people you do not live with

To reduce the risk of catching COVID-19, or passing it on, minimise the amount of time you spend indoors with people you do not live with. Meet outside if possible. If you do meet indoors, make sure the space is well ventilated. Avoid spending time with people you do not live with in spaces with a limited flow of fresh air, such as rooms without ventilation or windows that are never opened. The risk is greater in small rooms as the concentration of virus in the air can build up more quickly than in larger areas.

What you can do to improve ventilation

How you maintain or improve ventilation will depend on the building. Buildings are ventilated by natural systems such as vents, windows and chimneys, or by mechanical systems such as extractor fans or air conditioning, or a combination of both.

Ventilate your home

Opening windows and doors at home is the simplest way of improving ventilation for most people.

If windows have openings at both the top and the bottom (such as sash windows), using just the top opening will help incoming fresh air warm up as it mixes with room air, reducing cold draughts. In warmer weather, use both the top and bottom openings as this will help provide even more airflow.

Opening windows and doors at opposite sides of your room or home will also provide a good flow of fresh air (this is known as cross ventilation).

Make sure trickle vents (small vents usually on the top of a window) or grilles are open and not blocked. Air which flows in from these vents will mix with warm room air as it enters, which helps keep the room a comfortable temperature.

If possible, maintain openings throughout the day to allow a constant flow of fresh air into the home. The weather can affect the amount of air that flows through openings and so these should be adjusted to balance warmth with the amount of ventilation, where possible.

If someone is self-isolating

If someone is self-isolating, keep a window slightly open in their room and keep the door closed to reduce the spread of contaminated air to other parts of the household. If the person that is self-isolating needs to use any shared space in the home, such as the kitchen or other living areas while others are present, keep these spaces well ventilated, for example by opening windows fully during their use and for a short period after they have left.

If someone is working in or visiting your home

If you have people working in or visiting your home, let as much fresh air into your home as possible without getting uncomfortably cold while they are there, and for a short period before they arrive and after they have left.

Keep warm

Ventilating your home does not mean that it has to be cold. You should keep the temperature in the room you are in to at least 18ºC as temperatures below this can affect your health, especially if you are 65 or older, or if you have a long-term health condition.

In colder weather, where it is not comfortable to leave windows open fully, opening the windows slightly can also provide ventilation and reduce cold drafts.

There is advice available about how to keep warm and well. If you are having difficulty heating your home, you may be able to claim financial and practical help even if you don’t own the property. Visit the Simple Energy Advice website for information about the help that is available or call their helpline on 0800 444 202. Ofgem has further advice on what to do if you are struggling to pay your energy bills.

Mechanical ventilation in the home

If your home has a mechanical ventilation system, make sure this is working and maintained in line with manufacturers’ instructions. Set ventilation systems to bring fresh air in and not recirculate indoor air. Devices that only recirculate indoor air will not remove airborne virus from the home. You can use the boost mode (if available) to increase ventilation if someone in your household is self-isolating due to COVID-19 or if you meet people you do not live with indoors.

Ventilation can also be increased by leaving extractor fans in bathrooms, toilets and kitchen areas running for longer than usual, with the door closed, after someone has been in the room.

Ventilation in vehicles

Like buildings, enclosed vehicles including cars, vans, and buses can also be high-risk for spreading COVID-19. It is important that vehicles are well ventilated to help reduce the risk of spreading COVID-19.

Follow guidance on safer travel for passengers if you need to travel. Where you need to travel, consider walking or cycling if you can.

When operating or travelling in vehicles:

 

  • switch ventilation systems on while people are in the vehicle – set to drawing fresh air in, not recirculating air
  • to improve ventilation, windows can also be opened (partially if it’s cold) – heating can be left on to keep the vehicle warm
  • for vehicles that carry different passengers, such as taxis, clear the air between different passengers or at the journey end so the vehicle is aired before anyone else gets in
  • opening doors where it is safe to do so will help to change the air quickly – opening windows fully can also help to clear the air in the vehicle

Keep warm

Ventilating your home does not mean that it has to be cold. You should keep the temperature in the room you are in to at least 18ºC as temperatures below this can affect your health, especially if you are 65 or older, or if you have a long-term health condition.

In colder weather, where it is not comfortable to leave windows open fully, opening the windows slightly can also provide ventilation and reduce cold drafts.

There is advice available about how to keep warm and well. If you are having difficulty heating your home, you may be able to claim financial and practical help even if you don’t own the property. Visit the Simple Energy Advice website for information about the help that is available or call their helpline on 0800 444 202. Ofgem has further advice on what to do if you are struggling to pay your energy bills.

Please note: The guidance above is of a general nature and should be treated as a guide. In the event of conflict between any applicable legislation (including the health and safety legislation) and this guidance, the applicable legislation shall prevail.

Added benefits of ventilation. Pre-pandemic research into Home Indoor Air Qualityhome study suggested UK households were at risk of experiencing aggravated health problems due to poor air quality inside the home. 

The independent study tested the air quality in British homes; analysing the level of Volatile Organic Compounds (VOCs) present in the air. Out of the 122 homes tested in the UK, only 9% were considered in the normal category of recommended level of pollutant concentration, with the remaining 91% of homes above the recommended level (2) 

It's claimed that at the normal level, non-chemically sensitive individuals should not experience health issues from VOCs. As the TVOC level increases into the moderate, elevated or severe levels, individuals may experience aggravated health problems, and therefore, the need to address VOC issues becomes more critical.

Mould is one of the key factors of poor indoor air quality and health risk.  With winter upon us, condensation and mould become more prominent as we close windows and make our homes more airtight. Moulds release allergens, irritants and toxic substances. Other pollutants released by items around the home – such as fireplaces, candles, air fresheners, textiles, furniture, cleaning products paint and detergents - add to this, creating  a potent ‘pollutant soup’ in the home. 

Professor Peter Howarth told us, “There is a lot of noise about how outdoor air pollution affects your health, but we should look closer to home as this is where we spend most of our time. Indoor air can be more hazardous than outdoor air, particularly in young children and the elderly and where air quality is poorest. ‘Toxic home syndrome’ occurs when families are exposed to a potent mix of airborne pollutants arising from poor home ventilation, causing respiratory and skin diseases to occur more frequently.”  

If you have damp and mould, NHS Choices tell us that you're more likely to have respiratory problems, respiratory infections, allergies or asthma. Damp and mould can also affect the immune system.

Who's affected? Some people are more sensitive than others, including:

  • babies and children 
  • elderly people 
  • those with existing skin problems, such as eczema 
  • those with respiratory problems, such as allergies and asthma
  • those with a weakened immune system 
  • These people should stay away from damp and mould. 

How does it affect your health?  Moulds produce allergens (substances that can cause an allergic reaction), irritants and, sometimes, toxic substances. Inhaling or touching mould spores may cause an allergic reaction, such as sneezing, a runny nose, red eyes and skin rash. Moulds can also cause asthma attacks. 

Causes of damp and mould  Mould and damp are caused by excess moisture. Moisture in buildings can be caused by leaking pipes, rising damp in basements or ground floors, or rain seeping in because of damage to the roof or around window frames.

A newly-built home may be damp if the water used when building it is still drying out – for example, in the plaster on the walls. Excess moisture indoors can also be caused by condensation. 

If you have mould or damp it's important to find out why you have excess moisture in your home. When you know what's causing the damp, you can make sure your home is repaired or take steps to limit the moisture in the air. You may need to get a professional to remove mould for you, but if it's only a small amount you may be able to remove it yourself. 

Condensation Excess moisture indoors can also be caused by condensation. Condensation forms when the air indoors can't hold any more moisture. Cooking, showering, drying clothes indoors and breathing without adequate ventilation can all cause excess moisture. Droplets can form on indoor surfaces such as mirrors, windowsills and on walls, particularly when they're cold.

You can help prevent the build-up of condensation by:

  • putting lids on saucepans, drying washing outside and avoiding using paraffin or bottled gas heaters 
  • opening the bedroom window for 15 minutes each morning 
  • making sure your home is well insulated 
  • heating your home a little more 
  • ventilating rooms regularly and leaving doors open to allow air to circulate, unless you're cooking or showering 
  • if you're cooking, showering or bathing – opening the window, putting the fan on and closing the door of the room you're in 

Repairs may be needed to get rid of any leaks or to improve ventilation. Once your home has been repaired, or if your home is damp because it's newly built, it may take weeks of heating and ventilating it to dry it out.

How to remove mould  Once you've identified and fixed the source of moisture in your home you can get rid of any mould. You may be able to remove mould yourself, or you may need to get a professional to remove it. 

Only remove mould yourself if it's caused by condensation and covers an area less than one metre squared (1x1 metre or 3x3 feet). Don’t try to remove the mould yourself if it’s caused by sewage or other contaminated water. 

Protect yourself from mould spores by wearing goggles, long rubber gloves and a mask that covers your nose and mouth. Open the windows but keep doors closed to prevent spores spreading to other areas of the house.

Have a plastic bag ready to take away any soft furnishings, clothes and soft toys that are mouldy. Soft furnishings should be shampooed and clothes professionally dry cleaned. 

Fill a bucket with water and some mild detergent, such as washing up liquid or a soap used for hand-washing clothes. 

Use a rag dipped in the soapy water to carefully wipe the mould off the wall. Be careful not to brush it, as this can release mould spores. 

When you've finished, use a dry rag to remove the moisture from the wall. 

Afterwards, put the rags in a plastic bag and throw them away. 

All the surfaces in the room should be thoroughly cleaned by either wet wiping or vacuuming to remove any spores. 

Top tips for a healthy home

  1. Look into different ventilation options such as household mechanical ventilation systems which provide clean air or extractor fans. The bathroom is the most common place in the home where condensation builds up so it is essential that it is properly ventilated to reduce the risk of mould spores growing.
  2. Use eco friendly cleaning products - some everyday cleaning products contain chemicals known as volatile organic compounds (VOCs) which can be dangerous for your respiratory health.
  3. Consider wood flooring - carpets can harbour dust, dirt, dander, bacteria and cleaning products which can be hard to get out and release potentially harmful substances into the air, worsening your indoor air quality.
  4. Dry your washing outside otherwise make sure your windows are open if you have to dry it inside to reduce VOC levels indoors.
  5. Take your shoes off at the door so pollen, dirt, soil etc from outdoors is not spread around your home.

All material on this website is provided for your information only and may not be construed as medical advice or instruction. No action or inaction should be taken based solely on the contents of this information; instead, readers should consult appropriate health professionals on any matter relating to their health and well-being.