Coronavirus pandemic: What to consider when using your ventilation system

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There are countless theories surrounding the coronavirus and its spread. Hoval’s fact check tells you what you should be taking into consideration when operating your ventilation system during the pandemic.

According to the latest information, the coronavirus is spread via droplets as well as direct contact. This includes contact between people and touching things like door handles or taps, as the virus can survive for several days even on smooth surfaces.

While it is not currently possible to eradicate the virus completely, the heavily publicised hygiene measures that have been introduced as a matter of necessity can help to contain the spread. Washing your hands regularly, coughing and sneezing into the crook of your elbow, and practicing social distancing – that is, avoiding human contact as far as possible – are among the most important steps we can take to flatten the curve of infections.

No insights into coronavirus transmission through the air yet

We do not yet have any evidence to prove that the coronavirus is transmitted through the air.


That means the advice to keep your distance from people who do not live in the same household as you applies whether you are inside or outside.

There are also no specific insights into whether the coronavirus is transmitted through particular types of fresh air. Since we do not yet know if this is the case, there is nothing differentiating types of ventilation – whether you usually ventilate your home several times a day by opening the windows, or use a ventilation system to ensure that filtered air is always running through your home.

Aside from this, one point to note is that the natural flow of air is stronger than the flow effect of a ventilation system. An interesting example can be used to illustrate this: for a seated person, 80 m3 of air flows upwards through body heat alone, whereas just 30 m3 of air flows from the ventilation outlet of a HomeVent® comfort ventilation system.

Regularly replace the filters in comfort ventilation systems


A residential ventilation system, also known as a comfort ventilation system, exchanges used air for fresh air quietly, efficiently and hygienically. Allergy sufferers in particular can benefit from this kind of system, as the filter removes pollen, pollutants, fine dust and fungal spores from the air.

Thanks to the heat recovery function, no heating energy is lost despite the air Exchange. The extract air from the room is discharged to the outside, while filtered fresh air is brought into the living room. According to current findings, there is no possibility of the coronavirus being transmitted through outdoor air or leaked air in the unit. Filter classes commonly used today (F7 or ISO ePM1 50%) offer enough protection to eliminate any residual risk, however minimal this might be.
When operating your comfort ventilation system, you do not need to use higher filter classes or replace your filters any more regularly than you did in the past and as required as part of your usual maintenance process. The filters in Hoval’s HomeVent® comfort ventilation systems cannot be cleaned – and using a vacuum cleaner on them can actually destroy the filter structure, preventing the systems from working effectively. This means that the filters have to be replaced every 12 months – an interval that still applies even during the coronavirus pandemic. Filters for your HomeVent® residential ventilation system can be ordered via your local area sales manager.

Keep an eye on air humidity for healthy airways

It is important to keep an eye on the air humidity levels in your living areas, as dried-out mucus membranes are not very effective at filtering out dirt and bacteria. Increased dust pollution in living areas increases the feeling of dryness – but this cycle can be broken, as dust pollution is also dependent on how high the air humidity is. Specifically, dust pollution increases when air humidity is low.


Many doctors see a correlation between respiratory diseases and the level of air humidity in our own homes. However, the exact amount of air humidity that people perceive as pleasant varies from person to person. As a general rule of thumb, the relative air humidity in your home should be kept between 40% and 50%. This will cover all bases by stopping mucus membranes from drying out, but also preventing mould from forming.

Stay healthy with expert tips for your comfort ventilation system

With a HomeVent®residential ventilation system from Hoval, you can easily control the level of air humidity, reduce dust pollution in your home and effectively keep respiratory diseases at bay. We have put together a few tips to help you stay healthy:


In the control system of your HomeVent® unit, reduce the quantity of air introduced as the basic ventilation quantity and increase the humidity setpoint to 45% relative humidity. This will result in less humidity being lost.

  • Take care not to overheat buildings or individual areas of them. If you use a tiled stove to heat your living room from 21° and 45% relative humidity to 26°, for example, the air humidity in this area will drop to 33%.
  • Avoid additional ventilation via open windows or doors, as the dry outdoor air will reduce the air humidity in areas where this happens.

Reducing the quantity of air: things to remember

When you are reducing the quantity of air, it is important to remember that this will cause an increase in CO2. A CO2 value of more than 1400 ppm (parts per million) is still the maximum for occupied spaces. The increase in CO2 simultaneously gives rise to an increase in the air humidity. In addition, an air humidity level of more than 60% in living areas increases the risk of mould formation, as condensation can form more easily on windows or doors.

Find out more

To find out more on our HomeVent system click here.

Alternatively, you can contact your local Area Sales Manager here. 
Ian Dagley

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