There are up to one million homes in Finland without proper ventilation, writes Tekniikka & Talous. Helsingin Sanomat also recently wrote about the prevalence of inadequate ventilation, especially in terraced and detached houses built in the 1970s and 1980s.
There has been some concern about indoor air quality in recent times, but despite this, not many people in private homes take much interest in the functioning of ventilation. You also get used to poor indoor air quickly, making it easy to forget. However, poor ventilation can harm both the quality of life and the structure of a house. This is why it is important to know the basics of ventilation as a homeowner. In this blog, we will discuss how different ventilation mechanisms differ and why ventilation systems in domestic homes are often in need of renovation.
Finland’s most popular ventilation method performs poorly by current standards
Before the 1960s, almost all homes were equipped with gravity ventilation and , according to the Finnish Respiratory Federation, it is still the most common ventilation method in homes in Finland. However, this ventilation technology offers a poor outcome by today’s standards. Pressure ventilation is based on pressure differences between indoor and outdoor air. As a result, the efficiency of ventilation varies with the weather and often does not provide enough ventilation throughout the house. When the air is not properly exchanged, its carbon dioxide levels can easily become too high, causing chronic headaches and fatigue, for example. Odour and dust nuisances are also common for compressed air ventilation.
Exhaust fan causes harmful negative pressure
After the 1960s, mechanical ventilation began to compete with gravity ventilation. Mechanical exhaust ventilation is not much dependent on weather conditions, but it has its weaknesses. It has been common practice not to install replacement vents at all, or to install too few of them compared to the exhaust vents. This means that air is blown out of the house mechanically, but replacement air is not blown into the house at the same rate. The result is a negative pressure that “sucks” pollutants from the building’s structures into the air you breathe. Indoor air can thus be mixed with gases such as asbestos particles and radon, which can even pose a cancer risk.
Ventilation in exhaust ventilation systems is often inadequate and unecological due to its high energy consumption; when warm air is blown out without recovering heat energy, it is completely wasted. In addition, when the incoming air is not heated, the air currents create a sense of draught.
Mechanical ventilation and exhaust ventilation is a modern solution
Today, most new private homes rely on a mechanical ventilation system, where air is both blown in and extracted mechanically. In modern systems, the heat in the exhaust air can be captured and converted into electrical energy. These types of systems are energy efficient and often also effectively filter the supply air. This protects indoor air from outside pollutants such as street and pollen. Because the units blow both in and out at the same speed, no negative pressure is created, so no particles from the building structure or radon gas are drawn into the breathing air.
Poor ventilation in a detached house leads to damage to the house and health problems
As we mentioned earlier, poorly functioning ventilation can pose a health risk. Poor indoor air quality can lead to a wide range of symptoms, such as concentration problems, allergic symptoms and headaches. In addition, poor ventilation means that moisture from washing, showering, washing up and other normal living activities cannot escape effectively. Moisture in the air condenses on surfaces and can cause damage to paint and wallpaper. There is also a risk of moisture damage and mould growth.
Do you suspect your home has poor ventilation?
Poor indoor air quality is not worth suffering from. If your private house has pressurised ventilation or just a single exhaust vent, you should take advantage of a free indoor air survey. This way you will know the level of the air you breathe in your home and, if necessary, you will receive a quotation for an indoor air renovation.
You should be aware of the level of air quality in your home at the latest when you put your house up for sale. In a transaction between private individuals, the seller is liable for defects for five years after the transaction. The Health Protection Act (Section 26) stipulates that the cleanliness and ventilation of the dwelling or other indoor air must be such that they do not cause any health hazards.
