
In Finland, the problem is not a lack of knowledge, but that ventilation is underestimated. Although legislation and recommendations, such as the recent ventilation inspection, aim to improve the situation, the responsibility ultimately lies with the building owners and users. But what good is the inspection if the users don't even know what ventilation really means?
Mechanical ventilation is a system that literally keeps your house alive. It mechanically exchanges air and ensures that the indoor air remains fresh and healthy. This is not just a matter of comfort – it is a prerequisite for healthy living.
What the heck is mechanical ventilation ?
Mechanical ventilation and air conditioning are often confused, but they are different things. Mechanical ventilation means that the air in a house is exchanged mechanically. Various ventilation devices ensure that the indoor air remains fresh and healthy all year round.
Air conditioning, on the other hand, focuses on controlling the air temperature, such as cooling or heating, for example with an air source heat pump. For example, on hot summer days, air conditioning cools the room air, while mechanical ventilation keeps the air moving and ensures sufficient oxygen levels.
Mechanical ventilation can be divided into two types: supply-exhaust ventilation and exhaust ventilation. In supply-exhaust ventilation, both fresh air is brought in and old air is removed mechanically. This ensures better indoor air quality, as fresh air is constantly supplied. In exhaust ventilation, on the other hand, only old air is removed and replacement air comes in naturally, for example through window gaps. According to research, good ventilation reduces health problems and improves the well-being of residents.
Gravity vs. mechanical ventilation: Gravity ventilation is an older method where air circulates naturally inside a building without mechanical assistance. This is based on temperature differences and wind pressure. Mechanical ventilation, on the other hand, uses devices such as fans and ducts to move air in a controlled manner. It is more efficient and ensures better ventilation. You can read more about gravity ventilation in our article “ Mechanical vs. natural or gravity ventilation: which is better for controlling infectious diseases? ”
Mechanical exhaust ventilation: Many houses built in the 70s-90s have mechanical exhaust ventilation. This means that a roof fan removes used air from the apartment, and replacement air comes in through fresh air vents. It is important that there is enough replacement air, because otherwise air can be sucked in through the letterbox, drains or structures, which is not a good thing.
Supply and exhaust ventilation is king: Supply and exhaust ventilation is the most energy-efficient and comfortable ventilation method. It moves air into, out of and into a building in a controlled manner. This system is particularly good because it recovers 75-85% of the heat from the exhaust air. This is especially useful in winter when the outside air is cold. Studies have shown that mechanical ventilation improves indoor air quality compared to natural ventilation. Another study highlights how heat recovery saves energy and improves indoor air quality.
Supply-exhaust ventilation is like your own energy-saving guru! It utilizes heat recovery (HRE), which captures the heat from the exhaust air and uses it to heat the new, incoming air. This smart system reduces energy consumption and saves money on heating costs. HRE systems can recover up to 75-85% of the heat from the exhaust air (Seppänen & Fisk, 2002). Think of it, it's like your house getting extra heat for free in the winter when it's freezing outside!
In Finland, building regulations recommend heat recovery systems due to their efficiency. According to research (VTT, 2022), good ventilation improves indoor air quality and reduces respiratory symptoms. Heat recovery can save up to 50% on heating costs, so it is not only an environmentally friendly choice, but also a smart way to keep money in your piggy bank. So, if you want to be an energy efficiency superhero, a heat recovery system is definitely the right choice!
Challenges in apartment buildings
In apartment buildings, mechanical ventilation is a real lifesaver, as there are many people living on several floors, which makes natural ventilation quite difficult. Imagine how difficult it would be to get the air circulating properly without any aids! Mechanical ventilation ensures that the air in each apartment remains fresh and healthy. But herein lies the challenge: the ventilation system must be carefully designed and correctly sized so that it works efficiently and does not cause problems. You can read more about mechanical ventilation maintenance in our article “ Maintenance and use of mechanical ventilation: Responsibilities of the resident and the housing company ”
Challenges of mechanical exhaust ventilation
If the system is not in good condition, unpleasant problems can arise, such as the ventilation unit freezing in winter. According to building regulations, ventilation systems must meet the needs of the building. Poorly functioning ventilation can lead to indoor air problems and impair the health of residents. So, although mechanical ventilation is super important in apartment buildings, it also requires careful planning and regular maintenance to keep everything in order and the residents happy.

The obsolescence of ceiling fans
Rooftop vacuums are like the lungs of your home, keeping the air moving, but they also age over time. As the bearings in your rooftop vacuums wear out, they start to make noise and their performance decreases. Imagine trying to run a marathon with old, creaky knees – not very efficient, right? Regular maintenance is key to keeping your rooftop vacuums running smoothly and efficiently.
Building regulations recommend regular inspection and maintenance of ventilation systems. A well-maintained ventilation system can improve indoor air quality and reduce noise pollution. If your roof extractors start to make strange noises or feel like they are losing power, it’s time to call in a professional. This will ensure that your home’s ventilation system is working smoothly and that your residents can breathe fresh air without disturbing noise.
Blockage of make-up air valves

Replacement air vents are like the nose of your house – they let air in. But just as your nose can become clogged with dust and dirt, so can your vents. When your vents become clogged, your house’s ventilation becomes compromised, and the air can become stuffy. That’s why it’s important to change your vent filters regularly. It’s like giving your house a “nasal spray” to keep the air flowing smoothly!
In winter, valves can face another problem: freezing. When cold outside air flows in, moisture can accumulate in the valve, which then freezes. According to building regulations, ventilation systems must be well maintained. Regular maintenance improves indoor air quality and prevents problems. So take care of your valves and make sure your house breathes freely all year round!
Lack of ventilation and door gaps
Imagine that the air in your home is like traffic, and the bottoms of your doors are highway tunnels. If these tunnels are too narrow or don’t exist at all, air can’t move properly from room to room. This can cause an imbalance in ventilation and lead to stuffy indoor air. So, if your rooms feel isolated or the air isn’t moving, it could be because your door gaps are too small or there are no air vents.
There should be enough space under the doors for air to circulate (about 15-20 mm). Studies show that good ventilation improves indoor air quality and prevents health problems. So, if you want the air in your home to move smoothly and stay fresh, make sure there is enough space under the doors or the air vents are in place. It's like giving your house an open road for fresh air!
Excessive negative pressure
In mechanical exhaust ventilation, if the roof fan pulls too hard, it can suck in all sorts of unpleasant things, such as unpleasant odors from drains or other dirty places. This can happen if there is not enough replacement air. In other words, if your house does not get enough fresh air, it may start to draw in odors that you really do not want to smell. You can read more about the importance of pressure ratios in our article “ What is negative pressure and positive pressure and how do they affect ventilation? ”
It is important to ensure that the ventilation is balanced and there is enough replacement air. Studies show that good ventilation not only improves indoor air quality, but also reduces the risk of unpleasant odors. So, if you want to avoid unpleasant surprises, make sure that your home is well ventilated and has enough replacement air.
Supply and exhaust ventilation challenges

Problems with supply and exhaust ventilation start when the system is not working properly. This can be due to many reasons: air volume adjustment has been forgotten, equipment is outdated, ducts are dirty or filters have not been replaced. When these things are not in order, the system does not work efficiently and can even make indoor air worse. Ventilation systems must be maintained and functional. A poorly functioning heat recovery (LTO) system can, at worst, cause health problems, such as respiratory symptoms.
Neglecting to regulate air volumes
When residents adjust ventilation valves themselves, the air flow balance can be disrupted. This can lead to air not circulating properly between rooms, which can make the indoor air stuffy. In addition, valves becoming clogged with dust or ducts becoming blocked can cause even more problems.
Ventilation systems should be adjusted by a professional. Balanced ventilation improves indoor air quality and prevents health problems. So, let professionals adjust the valves and make sure that the valves stay clean and the ducts are open. This way, you will ensure that the air in your home remains fresh and healthy!
Neglect of maintenance

Regular maintenance is super important to keep your ventilation system working properly. If fans get old or filters get clogged with dust, ventilation will be significantly reduced. This can lead to poor indoor air quality and even health problems.
Ventilation systems require regular inspection and cleaning. An old and worn fan can cause noise and reduce efficiency, and dirty filters prevent air movement.
Winter challenges
One common problem in winter is the freezing of air handling units. When it is cold outside, moisture can condense and freeze on the internal parts of the unit, especially the heat recovery (LTO) cell. This can reduce the efficiency of the ventilation and lead to expensive repairs. To prevent freezing, it is important that the units are designed and installed correctly, and that the air volumes are adjusted correctly.
Air handling units need to be maintained regularly to ensure they work efficiently even in the coldest winter weather. Regular maintenance helps ensure that the units stay clean and work properly. This not only keeps the ventilation system efficient, but also prevents freezing and other problems that can lead to high repair costs. So take care of your air handling units, and they will take care of your home!
Mechanical ventilation and symptoms
Although mechanical ventilation often improves indoor air quality, sometimes residents can still experience symptoms such as headaches, breathing difficulties and fatigue. This is usually because the ventilation system has not been cleaned or maintained properly. When dust and impurities accumulate in the system, it does not work effectively, and indoor air quality deteriorates.
Regular maintenance and filter replacement are really important for maintaining healthy indoor air. By maintaining your system regularly, you will ensure that the air remains fresh and clean, and at the same time prevent health problems. So take care of your ventilation system, and it will take care of you!
Mechanical ventilation and possible health hazards
While mechanical ventilation often improves indoor air quality, sometimes residents can experience symptoms such as headaches, breathing difficulties and fatigue. This is usually because the ventilation system has not been properly cleaned or maintained. When dust and impurities accumulate in the system, it does not work efficiently and indoor air quality deteriorates.
In order for ventilation to work at its best, the system needs regular maintenance and filter replacement. A clean and maintained ventilation system ensures that the air circulates properly and stays fresh. This helps maintain healthy indoor air and reduces potential health problems. By cleaning the ventilation system and changing the filters, you ensure that the air stays clean and fresh. So take care of your ventilation system, and it will take care of your home!
Air source heat pump and ventilation

Air source heat pumps are becoming increasingly popular because they offer an effective way to regulate indoor air temperature, especially in summer. Air source heat pumps are also useful in winter, as they are 3-4 times more efficient at heating compared to direct electric heating. However, it is important to remember that an air source heat pump and an air exchange unit are different devices with different functions. An air exchange unit changes the air in a home, while an air source heat pump processes the air already inside. It does not bring in new air or remove used air.
However, today there are solutions that combine these two functions. For example, exhaust air heat pumps and high-tech LTO (heat recovery) units with a built-in air source heat pump can both heat and cool a property. This combination device can further improve energy efficiency and indoor air quality. Such multi-functional devices are becoming more common and offer a convenient way to keep your home comfortably warm and the air fresh all year round.
Mechanical ventilation and air-source heat pump in the same apartment
An air-source heat pump can support mechanical ventilation by improving indoor air temperature and energy efficiency.
Mechanical ventilation equipped with an air-source heat pump
If you have both an air handling unit and an air source heat pump at home, there’s no need to worry – they can even support each other, improving indoor temperature and energy efficiency. The air handling unit ensures that fresh air circulates in your home, while the air source heat pump regulates the indoor temperature. In winter, the heat recovery system recovers the heat produced by the air source heat pump, saving energy and keeping your home warm.
In the summer, the LTO system utilizes the cooled air, so the cooled air is not wasted. This helps to keep the indoor temperature comfortable without unnecessary energy consumption. Although these systems work independently, they effectively support each other. Together, they improve both ventilation and temperature regulation, making your home comfortable all year round.
Exhaust air heat pump
An exhaust air heat pump (PILP) is a smart device that reuses the heat from the air leaving the home. When ventilation removes warm air from the home, the PILP captures this heat and uses it efficiently. It transfers the heat back to the supply air, the water-circulated heating system and the domestic water. This significantly saves energy and improves living comfort. Exhaust air heat pumps are very efficient and can compress the temperature of the exhaust air to as low as -15 degrees.
PILP is ideal for both new and old buildings and works well in combination with electric heating. The best models can heat effectively down to -25 degrees Celsius, which is convenient in the cold Finnish conditions. However, it is important to keep the pump running continuously in severe frosts, as switching the device off and on again at temperatures below -25 degrees Celsius can cause damage. An exhaust air heat pump works best in low-temperature heating networks, such as underfloor heating, and requires an exhaust air duct or an intake-exhaust air duct. Many models also have a cooling function, which makes the summer heat more bearable.
The use of exhaust air heat pumps is becoming more and more common due to their energy efficiency. They offer an environmentally friendly solution for heating and cooling your home, and their efficiency is constantly improving with new technologies. By installing a PILP system, you can save on energy costs and reduce your carbon footprint at the same time. Regular maintenance and proper use will ensure that the device works for a long time and efficiently, while providing optimal indoor air quality and temperature all year round.
Supply and exhaust ventilation with heat recovery and cooling

Supply and exhaust ventilation systems with heat recovery and cooling are very convenient. These systems can utilize an exhaust air heat pump (PILP) or use other solutions if the heat does not need to be used to heat domestic water or water-based heating. Many manufacturers of ventilation units have units with a built-in air heat pump. This pump takes care of both heating and cooling. In summer, these units can cool the indoor air up to 12 degrees below the outdoor temperature.
This type of cooling system does not require a separate outdoor unit, so installation costs remain low. This is especially convenient in places where outdoor units are not allowed due to facade regulations. Installation and commissioning usually go smoothly without special cold installation rights. However, it is important to ensure that the supply air ducts are insulated. Otherwise, they can collect moisture and cause moisture damage. In older buildings where the ducts run inside the structures, making such an upgrade can be almost impossible.
Maintenance and cleaning of mechanical ventilation
In apartment buildings, the housing company usually takes care of the maintenance and cleaning of the ventilation system, but it is important for residents to know what needs to be done. In the supply and exhaust ventilation system, the filters must be changed at least twice a year. Many systems also have winter and summer settings that must be adjusted manually, usually when changing the filters. The ducts must be cleaned according to current regulations, and it is the residents' responsibility to monitor the situation and report if cleaning is necessary. You can read more about the maintenance of mechanical ventilation in our article " Maintenance and use of mechanical ventilation: Responsibilities of the resident and the housing company "
In mechanical ventilation, replacing the filters in the replacement air valves may be the responsibility of the resident, and they should also be replaced at least once a year. If the filters become clogged or the settings are not correct, the ventilation will not work effectively, which can reduce indoor air quality. So take care of your ventilation system, and it will take care of you and your home. Neglecting maintenance can lead to poorer indoor air quality and possible health problems, so regular maintenance is important!
Maintenance of the ventilation system: Regular maintenance of the ventilation system is important to ensure that it works efficiently and lasts a long time. This means changing the filters at least twice a year and checking that the settings are correct for summer and winter. If the filters become clogged, the system will not work properly and the indoor air can deteriorate.
Cleaning the ventilation valve in an apartment building: In apartment buildings, ventilation valves must be cleaned regularly to prevent them from becoming clogged. Residents are responsible for replacing the valve filters at least once a year. It is also important to monitor the condition of the ducts and notify the housing company if they need cleaning. The housing company is usually responsible for cleaning the ventilation ducts, but residents should be aware of the need for maintenance.
Home air conditioning maintenance: Air source heat pumps require regular maintenance at least twice a year. This includes cleaning the filters and a general check of the unit. Air source heat pumps collect a lot of moisture, and after the cooling season, microbes can start to grow on their internal parts. Therefore, it is very important to clean and disinfect the unit regularly to prevent it from spreading mold spores throughout the home.
Cleaning of ventilation ducts in housing associations: In housing associations, ventilation ducts should be cleaned regularly to ensure that the system works properly. Unclean ducts can collect dust and dirt, which impairs ventilation and can cause health problems. Regular maintenance ensures that air circulates well and residents breathe clean air.
Ventilation interruptions
Ventilation outages can cause poor indoor air quality, so it's a good idea to keep this in mind. Ventilation should never be turned off completely for a long time. If the system is off for too long, the indoor air can become stuffy and unhealthy. During power outages, ventilation may stop, but don't worry! You can keep your indoor air quality good by manually ventilating. Open the windows and let fresh outside air flow in. This will help remove indoor pollutants and keep your home comfortable. However, remember that in winter, you should be careful not to let your home get too cold. If you know that a power outage is coming, you can prepare in advance and think about how to ventilate the premises in the best possible way. Keep ventilation in mind even when power outages are possible, and make sure that the air in your home remains fresh and healthy!
IVAeris Oy offers expert solutions

IVAeris Oy specializes in the design, maintenance and improvement of mechanical ventilation systems to ensure they operate efficiently and as intended. Our team of experts is dedicated to helping you achieve a healthy indoor environment.
How can IVAeris Oy help you?
Assessment and Diagnosis: Our professionals will assess your current ventilation system, identify potential problems, and provide a detailed diagnosis.
Customized solutions: Based on our assessment, we recommend customized solutions to improve your ventilation system, whether it's adding valves, improving existing ones, or integrating mechanical elements to improve performance.
Maintenance Services: Regular maintenance is key to keeping your system in top condition. We offer cleaning, inspection and repair services to ensure continuous and efficient operation.
Upgrade and Installation: If your system needs significant improvements or a complete upgrade, we offer installation services for new ventilation systems designed to meet the latest standards and your specific needs.
Why choose IVAeris Oy?
With our extensive experience in mechanical ventilation systems, our team has the knowledge and skills to solve any ventilation challenge. We prioritize your health and comfort, ensuring that all the solutions we provide are of the highest quality. Our commitment to excellence means we work closely with you to understand your needs and deliver solutions that exceed your expectations.
Act now
Don't wait until ventilation problems affect your health and comfort. If you suspect that your ventilation system is not working as it should or if you have concerns about indoor air quality, contact IVAeris Oy today.
By addressing your ventilation needs quickly and efficiently, you can ensure a healthier and more comfortable living environment for yourself and your family. Proper ventilation is not just a feature of your home; it is an essential part of maintaining a safe and comfortable place to live. Contact IVAeris Oy for expert advice and solutions that will keep your home's air quality at its best.
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IVAeris Oy
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