Clean up indoor air pollution for your health

◄ Back to all articles

We spend more than 80% of our time indoors, and take 15,000-20,000 breaths per day. But did you know, the pollution inside your house, office and children’s school could be up to 100 times worse than the outside??? 

The air in our homes, offices and schools has a huge impact on our health. If you do not have proper ventilation, all the harmful substances such as dust mites settle in yours and your family lungs. 

Buildings today and in the past

“Building more tightly-sealed houses over the last two decades has made it much easier for moisture and dust to collect in homes,” Harvard professor Dr. Douglas Dockery notes.1

In the past, the poor insulation and finish of homes allowed for plenty of natural ventilation. Gaps between floorboards, thin, single-glazed windows and simplistic building techniques all contributed to the constant flow of fresh air into homes. Nowadays Thermal insulation is becoming increasingly effective in modern buildings. On the one hand, this saves energy. But on the other hand, good insulation prevents the exchange of air that once took place through the permeable building envelope and windows of older buildings.

Health – our biggest treasure

An adult man daily takes around 22 thousand breaths, absorbing from 15 to 20 thousand litres of air. With each breath we inhale between 40 to 75 thousand dust particles. One gram of dust contains 700 million different molecules that may pose a huge threat to your health. The same applies to our children, if we do not ensure a good quality of air in our home, we expose them to allergies and even asthma.


Tiny particles and germs circulating through your home’s air can trigger allergy symptoms or cause other discomforts, such as headaches. If your children have allergies or asthma, the ventilation is crucial. 

Pure ventilation can lead to condensation, too much humidity and high levels of CO2 in your home. What does it mean?

The air will accumulate various pollutants - mainly exhaled carbon dioxide by us, omnipresent dust and mites, and even mold spores. If there are smokers in the house – the poisonous substances that settle into the furniture in your home can be released any time.

House dust mites: 


The air exhaled by people and the imperceptible process of sweating causes an increase in air humidity. The water vapor is deposited on the cold surfaces, eg. On the windows and the corners of rooms. Moist surfaces are nutrients for dust mites which can be a cause of allergy. Mold spores attack food, and destroy the wall on which it is formed.

Extended time spent in rooms that are poorly ventilated can be very harmful. It can cause drowsiness, headaches, dizziness, poor attention, weakness, nausea and general fatigue, and even depression. Sometimes the body can also react to irritation to the eyes and respiratory tract, and even cardiac arrhythmia. You also can not underestimate the effect of carcinogenic mildew ...

Ventilation should also remove moisture from the house, which is produced from breathing, ironing, cooking, drying laundry, and smells that continually arise in closed residential spaces.

How much fresh air do we need?

The general rule is that within an hour, the air in the living room needs to be replaced:

As much air as is its cubic capacity or 30 m3 of air for every person in the room (if these two numbers are different – choose the larger number)

As an Example: A living room with an area of 20 m2 requires 50 m3 of air per hour, but when it is a bedroom for two people - up to 60 m3 / h.

Slightly different to this is the quantity of fresh air which should be brought to the premises of "dirty" rooms such as kitchens and bathrooms which call for intensive ventilation during use. And yes:

In a Bathroom we need a minimum of 50 m3 / h,

A kitchen with an electric stove must escort of 50 m3 / h, and if the stove is gas - 70 m3 / h.

Separate requirements apply to the living room with fireplace, boiler room, laundry and drying room - must be consider with planner.

Home-check whether the ventilation is sufficient to measure the humidity of indoor air in winter. If it amounts to a maximum of 50-60%, this means that the ventilation functions properly.

Schools and ability to learn

Often class rooms are not properly ventilated to meet the demands of the children and to ensure a good air quality. Class rooms are characterized by many students per square metre; this often leads to a high CO2 level and a poor indoor air quality.

That may cause students to suffer headaches, lack of concentration ability, and unnatural tiredness. Also, problems of draught may occur if the room is primarily ventilated via open windows.


Studies by the Danish Technological University  document a clear connection between air quality and air temperature and the performance of the students. Tests performed at Danish schools show that by establishing mechanical ventilation room temperatures can be reduced from approx. 25° to 20°C which improved student performances by up to 10%.

Another study of, Dr. Richard Shaughnessy, of the University of Tulsa, believes it's possible to predict student performance in the classroom. That's because he's found a connection between cool, fresh air and better test scores.

“Improving ventilation, bringing in more outdoor air and lowering temperatures in the classroom dramatically improves students’ ability to achieve,” Shaughnessy said.2

Is office air quality ruining your productivity?

Another Harvard study found the indoor environment had significant impact on work. Participants were tested on anything from basic tasks to crisis response. If we have not enough fresh air our attention, creativity and productivity dramatically decreased.


What is the solution?

The best is to have the smart system ventilation, where you don’t need to open and close the windows and your air is always in good condition, no matter the season or outdoor temperature.

The ventilation unit recommended is HomeVent®, which regains heat from the extract air, but it also recovers humidity– something that few conventional systems are capable of doing.

Hoval HomeVent®


An insect filter removes larger particles from the fresh air that is drawn in. An additional high-performance fine filter cleans the air of pollen, pollutants, fine dust and fungal spores. When the air reaches the interior of the building, it is clean. Stale indoor air and undesirable particles and odors are removed from the building with the extract air. Because you no longer need to open the windows to obtain fresh air, noise stays outside, too.

Saves investment costs

The heat and humidity recovery technology makes the HomeVent® exceptionally economical.

By way of comparison, good conventional systems reach a heat recovery efficiency of up to around 90%. HomeVent®, on the other hand, achieves up to 130% with its patented operating concept. The result is a pleasant indoor climate.

The HomeVent® system significantly improves the energy balance in your building. The system saves considerably more energy than it consumes for operation. The air quantity is continuously variable and is specified using the operator terminal. Two low-energy EC fans work fully automatically to draw in fresh air that is free of pollen and dust from the outside in the required quantity and transport used air from the interior to the outdoors.

If healthy indoor climate catch your eye, please share!

Patrik Woerz
Segment Manager Domestic Ventilation