Media release / 18.5.2026
Stuffy or dusty indoor air, window condensation and slow-drying bathroom surfaces can be signs of poor ventilation. Ville Kilpi, Director of Property Management at Lumo, explains what you can do to improve indoor air quality.
Lumo Homes has over 50 years of experience and more than 40,000 homes’ worth of knowledge on factors affecting indoor air and ventilation performance. A few small but important details are often overlooked in everyday life.
Director of Property Management Ville Kilpi explains how to ensure that indoor air remains as fresh as possible.
1. Ensure ventilation valves are functioning properly
Keep supply air valves and exhaust air valves clean, as dust buildup reduces airflow. Wipe the valves with a damp cloth at least once a year, preferably more often.
You can test the function of an exhaust air valve by placing a sheet of household paper against it. If the paper stays in place, ventilation is working correctly.
“There is no need to remove the valve for cleaning. When cleaning, it is also important not to change the valve settings, as the ventilation system is balanced for the entire building and any adjustments affect the system more broadly,” Kilpi notes.
Do not close or block fresh air valves, also known as supply air vents. Blocking fresh air valves prevents fresh air from entering the apartment.
“There have been cases where residents have taped over a valve to avoid draught. Taping is never the correct solution for ventilation,” Kilpi reminds.
How to recognise different valve types
“Devices differ in appearance, so it is easier to identify them by location,” Kilpi summarises:
- Supply air valve: located in living spaces such as the living room
- Exhaust air valve: located in kitchens and bathrooms, and may also be found in walk-in wardrobes
- Fresh air valve: installed in the external wall of the apartment or in the window frame
“If you are unsure what type of ventilation valves your home has or how they should be cleaned, you should contact maintenance or the property manager. In Lumo homes, this can be done conveniently via the My Lumo service,” Kilpi advises.
2. Keep the cooker hood or extractor fan clean
The grease filter in the cooker hood or extractor fan should be cleaned at least a couple of times a year, and even monthly depending on how much cooking is done.
A clogged cooker hood does not extract properly, which allows cooking odours and steam to linger in the home, potentially causing not only a stuffy indoor air environment but also moisture damage.
Remove the grease filter from underneath the cooker hood and wash it with hot water, a dish brush and a grease-dissolving washing-up liquid, or place it directly in the dishwasher.
“If you are unable to remove or clean the filter yourself, you should contact maintenance for assistance. This is something we all easily forget as everyday life takes over,” Kilpi notes.
3. Ventilate effectively
Ventilation can be temporarily improved by airing out the home. Intensive ventilation for 5–15 minutes is sufficient. Windows or balcony doors should not be left open longer than this.
“Many people make the mistake of leaving a window open all day. Heat escapes, street dust, pollen and insects enter the home, and in case of rain there is even a risk of water damage,” Kilpi explains.
Cross-ventilation is always the best option if possible. However, the front door leading to the stairwell should not be used for this purpose.
Early morning or late evening are the best times, when traffic-related dust and construction activity have subsided.
“If you suspect that your home’s ventilation is not working properly, you should contact maintenance or the property manager,” Kilpi advises.
The same advice is repeated for good reason. It is in both the resident’s and the landlord’s interest that ventilation works properly — for comfort, health, and the long-term condition of the property.
For more information: Ville Kilpi, Director of Property Management, Lumo Homes plc, tel. +358 20 508 3407, ville.kilpi@lumo.fi