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How PIV Systems Improve Indoor Air Quality

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How PIV Systems Improve Indoor Air Quality

By Ruth MacEachern

Product Manager

Jun 30, 2023

Hay fever can affect people from March through until September and has multiple waves.  It is perhaps the most common type of allergy suffered in the UK with almost 50% of the population having some symptoms over the course of the season.

Over the course of the hay fever season different types of pollen are prevalent, and sufferers may experience reactions to some or all the different pollens over the course of the year. 

During the summer months, when allergies are at their worst, people with hay fever may struggle to get through the day without suffering, and even opening a window in their home to let fresh air in can trigger a reaction.  Poor ventilation in a home can worsen air quality, and in some cases cause a build up of other allergens as well as preventing pollen that has been brought into the property from escaping.

How good ventilation can help reduce allergies

In most cases, allergic reactions get worse with higher levels of a particular allergen.  At low concentrations of pollen or dust, people are less likely to encounter it, and as such a reaction is less probable.  This is why people with hay fever will often keep their windows closed during the summer to reduce pollen levels in their home.  Unfortunately, over time, this does not work.  Microscopic pollen grains can be brought into a property on clothing or through normal air gaps.  Levels can quickly build up, and with limited air movement in the property will start to concentrate in areas where people spend a lot of time.

Improving the airflow in a property helps to reduce the concentration of pollen in certain areas which is helpful for hay fever sufferers, but without regular transfer of air from outdoors into the home, levels will eventually build up.

Positive Input Ventilation (PIV) systems are an excellent solution for people with hay fever or other allergies.

How PIV systems can help hay fever sufferers

PIV systems draw fresh air from outside the property in through a central unit that is mounted in the loft and then distribute the fresh air throughout the building to displace stale or humid air.  Modern PIV systems such as EnviroVent ATMOS feature air filters to remove particles from the incoming air such as pollen grains to prevent them entering the home. 

The way PIV systems circulate air into a house increases the air pressure slightly, and this helps to reduce the amount of pollen or other allergens that can enter through other routes such as doors and windows. 

This combination of filtering incoming air and pushing outwards to prevent pollen from entering the home from other sources can make life more comfortable for hay fever sufferers.

PIV systems and indoor air quality

The major advantage of a whole house ventilation system is that it improves the airflow in every room of your home.  Aside from allergens such as pollen and mould spores, PIV systems reduce the concentration of chemicals released from cleaning products and other materials throughout your home.  Volatile Organic Compounds (VOCs) can build up in a poorly ventilated home and create issues for people with respiratory conditions such as asthma.  With a PIV system, as fresh air is brought into the building, it displaces the air containing VOCs and reduces their concentration, which helps to reduce their effect.

PIV systems and condensation

Condensation on walls, ceilings and windows is caused when the temperature of air falls and it can no longer hold as much water vapour.  Humid air coming into contact with cold surfaces forms droplets of water on the surface.  This is most noticeable in bathrooms and kitchens where a large amount of steam is released by bathing and cooking, however water vapour is also released into the air from respiration which is why we often see condensation on bedroom windows in the morning.

As condensation soaks into porous surfaces such as walls, it creates damp patches.  These provide the perfect environment for mould to grow and also allow dust mites to thrive.  Both mould and dust mite waste are highly allergenic.

While extractor fans in your bathroom and kitchen will reduce the humidity in those rooms, they will have less of an impact in the rest of your home.  A whole house PIV system gently replaces the humid air with fresh air from outside, which reduces the average humidity below the dew point (where condensation forms). 

As PIV Systems prevent condensation, throughout your property they also stop damp patches from forming, and this takes away the conditions required for mould which makes your home a healthier place.

PIV systems and radon

In some parts of the UK, radon gas can be a major health risk.  Radon is a colourless and odourless radioactive gas that is released by the decay of chemicals below the ground.  It seeps up through the earth and can build up in properties.

The presence of radon gas in your home increases your exposure to dangerous radiation and can increase your risk of some kinds of cancer.  People living in high risk areas should have a detector in their home to monitor radon concentration and ensure that it does not reach dangerous levels.

PIV Systems are highly recommended in properties located in high radon parts of the country.  They reduce the concentration of radon in the air, and this in turn will help to prevent the creation of “radon daughters” – dust particles that have been ionised by the radiation – which helps to improve the quality of air in your home and reduce your exposure.

Find out more

If hay fever symptoms are stopping you from enjoying your home this summer, we can help.  Our local ventilation experts can visit your home and provide advice about the best system for your needs.  Simply enter your postcode below to request a free home survey from a specialist in your area.

Need help with condensation, mould or damp problems?

One of our local experts will contact you to learn more about your problems, offer free expert advice and make recommendations for a permanent solution.

During the free survey we will

  • check Assess any condensation, damp or mould problems in your property
  • check Take readings of the relative humidity levels
  • check Identify any underlying problems and make recommendations for a permanent solution

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