Many Finns appear to know surprisingly little about how ventilation works in their homes, according to a nationwide survey commissioned by Finnish ventilation company Velco.
A total of 26 percent of respondents said they had no idea what type of ventilation system their home uses.
The lack of awareness was particularly common among people living in apartment buildings. Around one in three apartment residents said their home ventilation system was a complete mystery to them.
“Ventilation is basic home technology. People often only start paying attention to it when the air feels stuffy, there is an uncomfortable draught or the windows are open all year round,” Velco CEO Peter Schlauf said in a statement.
Finland had around 3.28 million dwellings in 2025, according to Statistics Finland.
The survey found that only 60 percent of respondents considered their indoor air quality good and their ventilation adequate.
Among apartment residents, the share was 53 percent, compared with 70 percent among people living in detached houses.
Satisfaction was also lower in older homes. According to the survey, around half of people living in homes more than 50 years old rated their ventilation as only moderate or poor.
This is a significant group in Finland, where nearly one-third of the housing stock was built during the 1960s and 1970s.
One in three report symptoms they link to indoor air
A total of 35 percent of respondents said they had at least occasionally experienced symptoms at home that they associated with poor indoor air.
Among apartment residents, the share rose to 44 percent.
Schlauf said symptoms associated by residents with poor indoor air can include headaches, fatigue and irritation of the eyes or respiratory tract.
He stressed that such symptoms should not simply be ignored, although the survey itself does not establish what caused them.
Many open windows to get fresh air
Opening windows appears to be a common response when indoor air feels inadequate.
Around 60 percent of respondents said they at least sometimes feel the need to open a window to get fresh air. Among apartment residents, the figure was 70 percent.
“Opening windows is not only a matter of habit. It may also indicate shortcomings in ventilation,” Schlauf said.
In homes with properly functioning natural ventilation or mechanical exhaust ventilation, fresh replacement air should enter through dedicated vents while used air exits through exhaust ducts.
The survey also found that apartment residents were more likely than people in detached houses to ventilate by opening windows during winter.
Some 59 percent of apartment residents said they did so at least occasionally to get fresh air, compared with 32 percent of detached-house residents.
Schlauf noted that opening windows during the heating season also allows heat to escape.
“Proper ventilation should continuously bring fresh air into the home without residents having to manage ventilation regularly by opening windows,” he said.
The nationwide survey was commissioned by Velco and carried out by research company Bilendi in August 2026. A total of 1,000 Finnish adults took part, with the sample quota-controlled by gender, age and region of residence.