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Summer and your MVHR ventilation unit

25 April 2025 | HRV

Do you want a Comfortable Sneeze-Free Summer?

Summer By Pass and Pollen Filters at the ready. 

Your MVHR system works 365 days a year to contribute to your comfort! As it works, it helps reduce humidity and pollution from your home and bring in fresh filtered air. 

In the Winter, your system recovers the heat from the extracted air and passes it to replacement air, helping you reduce that thermostat and your energy bills, but what about the summer? 

You definitely dont need the heat recovery and you've also got pollen to deal with as well!

What role does your MVHR system play in the summer?

Your MVHR heat recovery unit is keeping your home as comfortable as possible -  the continuous flow of moving air helps creates a cooling effect in the warmer months. Dont turn it off - you will feel warmer than ever!

We all typically reach for the window to help in the summer but you often need two windows or doors directly opposite each other for the air to move around effectively - and then you are just allowing more outside pollution and particles to enter your indoor environment.  Your MVHR system means you dont have to open the windows and it's also crucially filtering the air coming inside the property as well.  

The 'Summer Bypass' Mode?

The one thing you dont need in the summer is heat recovery. Throughout the year, your MVHR unit recovers and reuses heat to put back into your home to reduce the heating bills (about £300 per year in a new build) - great in the winter, but not so much in the summer. The Summer By Pass mode automatically activates based on outside termperature levels and stops recovering and resuing heat. Instead the MVHR system continues to work, providing fresh, filtered air to your home continuously. You will see a bypass arrow on the unit display or controller which will indicate that the summer by pass mode has been activated. 

What about summer filter options?

Pollen peaks in May and can linger until late August – reaching highs of over 150 grains per cubic meter of air - up to 5 times higher than a normal day. Leading to itchy eyes and runny noses, effecting both your sleep and day to day. 

We recommend the Summer Sneezer  (M5 Grade) that are designed to filter out much finer particles that may irritate you such as dust and most importantly, pollen. These thicker grade  filters captures the pollen and particles and are ideal for those suffering with allergies. (The Summer Sneezer filter comes with the yellow tab and is only required for the SUPPLY air side)

Our partners at The Air Shop 15% off all Summer Sneezer filters in May, just use code SSFILTER15OFF at checkout!

What is the role of filters in the the MVHR System?

Filters play an important part in your MVHR heat recovery ventilaton system protecting the motors from dust, debris and grease and helping remove outside air particles to improve your indoor air quality.  

The filter you choose can be tailored to your indoor air quality needs as well as the seasons, You can tackle issues such as allergies, dust, hayfever, pollution, pet hair allergies and more! Choose from The Basic Barrier, The Dust Destroyer, The Summer Sneezer or The Propper Stopper!

Filters should be checked and replaced minimum every 6 months - but an annual service is also recommended.

We always recommend changing your filters every 6 months (or less if you live in a highly polluted area or have more specific air quality needs) your filters are capturing so much dirt and pollution and over time become clogged up (when you change your filters and you see the dirt covered layer, that is what your looking at!) so in order to have comfortable, fresh air in your home, it's important you have clean filters at least every 6 months.

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