Can Indoor Air Quality Become Worse in Summer?

It is a common misconception that by opening your windows during summer, you are improving your indoor air quality. But this is often not the case, by opening your windows you may be letting pollen and other allergens to enter you home which can be potentially harmful.

It is important to ventilate your home at all times of the year. The need for ventilation doesn’t not change with temperature or humidity. To ensure your indoor air quality is always at optimum levels, it is important to ventilation all day, all week and all year.

Installing a mechanical ventilation heat recovery (MVHR) system is the best way to continuously ventilate your home. A MVHR system will extract any moisture, pollutants and allergens from your home, while also supplying fresh, filtered air.

How your Indoor Air Quality Can Become Worse in Summer:

Mould – more humid climates mean that mould is more likely to grow

Dust Mites – warmer atmospheres bring out dust mites due to the increased temperature in warmer months. Dust mites thrive in warm and humid conditions

Time Spent Indoors – between work and home we spend at least 90% of our time indoors, spending long periods of time in an improperly ventilated property can be detrimental on your health, concentration and alertness

Carbon Monoxide – a odourless and colourless gas that can cause significant health issues – carbon monoxide poisoning can increase during warmer months as it is a by product of burning gas without sufficient air supply.

How to Combat Poor Indoor Air Quality in Summer (and all year!)

Ensure your home is properly ventilated – you can do this by installing a mechanical ventilation system. Our top recommendation is a Mechanical Ventilation Heat Recovery (MVHR) system, other options include Mechanical Extract Ventilation (MEV) systems and Positive Input Ventilation (PIV) systems.

There are many ways that you can help to improve your indoor air quality such as:

Humidity control – controlling humidity levels in your home will limit condensation and mould growth in your home

Cleaning your home often - by vacuuming, washing and general cleaning will reduce dust mites and general uncleanliness in your home. Have you considered installing a central vacuum system? – check out more info here.

Replace your filters – checking and replacing your filters regularly are important to ensure that your system is supplying the best quality air that it can.

Air Sealing – ensuring that your air ducts are properly sealed will ensure your ventilation system will work properly and efficiency, meaning that you will have the best indoor air quality through your home. Air ducts should be sealed properly during the time of installation, but we recommended checking ducts to ensure there are no air leaks.

Allergens in Summer 

Although allergies are caused by the pollen from many different plants and grasses that are outside, these pollutants can very easily enter the home. Allergens are higher in levels throughout the warmer spring and summer months. Pollutants can enter the home via open doors, open windows, trickle vents and gaps. By properly ventilating your home, you can reduce the risk of allergens.

Summer is the one of the most important times of the year to ensure that your home is properly ventilated. Although across the UK and Ireland, we may not consider ourselves to have great summers, it does get warmer, more humid and along with that, there is an increase of pollen and with extra heat, there can be rise of excess condensation, damp and mould build up in your home.

Heat recovery system differ from conventional air conditioning systems as an air condition system will recirculate the air, but a heat recovery system will provide new, fresh and clean air.

Tips for Better Home Air Quality


We have large number of replacement filters for specific units from a range of leading manufacturers including Vent-Axia, Airflow, Mitsubishi and more!

See all filter options. Some units have the option to upgrade to F7 grade pollen filters, these are available for units such as the Vent Axia M5 BH/E/V, Highflow/Plus B, Airflow BV400 and Airflow Adroit Units.


We recommend that filters are checked every 3-6 months. Filters must be changed at least once a year to ensure the best indoor air quality.

Can Ventilation Help my Hay Fever?

Hay Fever is caused by an allergy to pollen and affects around 1 in 5 people in the UK.

Hay fever season can typically run from May through to September. In 2019 there has been high pollen risk announcements made, so we recommend if you haven’t changed your filters already this year to change your filters now! If you have not already, we recommended upgrading to pollen filters, especially during the summer/higher pollen months.

There is no cure or treatment for pollen allergies but having a ventilation system can massively help. It can help by reducing the amount of dust mites, pollen, pet fur and irritants from building up within the home. It will also provide fresh filtered air into your home while reducing the risk of condensation and humidity. By eliminated condensation, this will reduce amount of mould and damp build up, making your home a healthier, allergy living environment.

Let us Help You

Are you interested in improving your indoor air quality? It is never the wrong time or season to begin ventilating your home! Send us your plans today and our estimators will send you a quote based on your house plans and you will be one step further to having the best indoor air quality!