Air conditioning or ventilation?

Air conditioning or ventilation?

Air conditioning and ventilation have different operating principles. This article explains the difference between the two.

Air conditioning or ventilation?

Healthy and fresh indoor air is key to a good quality of life. It is much nicer to work when the quality of the air is good without a constant need to open the windows, and to go home to fresh air. Both air conditioning and ventilation help improve the quality of indoor air. Although easily confused in everyday language, the two affect the air in different ways. How do they differ and what should be taken into account regarding them?

Air conditioning and ventilation

Ventilation simply means that the used and “dirty” indoor air is removed and replaced with new, fresh, and oxygen-rich air. Ventilation makes it easier for us residents to be and to breathe. Ventilation also keeps the structures of the apartment in good condition. Air conditioning with a separate unit, on the other hand, means that indoor air is recycled and its qualities are changed e.g. by cooling it or removing moisture. Air conditioning does not bring new air into the apartment.

If your bed is soaked in sweat on summer mornings, an air cooler or the cooling function of an air-to-air heat pump can make you feel more comfortable. An air-to-air heat pump also helps heat the building in colder months. Ventilation, on the other hand, keeps the air fresh and easy to breath at all times- regardless of the season. Its cooling capacity is, however, limited. Technically ventilation and air conditioning can be implemented either by means of one or completely separate units.

Air conditioning implemented by means of an air-to-air heat pump does not bring new air into the indoor premises.

Air conditioning can be implemented e.g. by means of an air-to-air heat pump mounted on the wall, a portable air conditioning unit, a fan convector, or a cooling beam. These devices recycle indoor air and modify its qualities by cooling and removing moisture, but they do not replace the air. Therefore, the processed air is always the same, only the qualities change. When cooling, units condensate water from the recycled indoor air, therefore removing moisture from the air. This is even more important for the comfort of living than cooling, because humidity feels uncomfortable on the skin - very much like sweating. No one wants to sweat all the time.

Because air conditioning units recycle the air, they do not remove smells relating to everyday life from it. These smells are caused e.g. by cooking, breathing, and the washing of clothes. While an air-to-air heat pump helps heat the building in cooler months, it cannot reduce the humidity load caused by showering and sauna - even when used for heating.

Air conditioning can be implemented by means of a separate unit or it can be integrated with the ventilation system of the building. A duct radiator installed in the supply air channel of the ventilation system cools the air flowing in into the apartment and removes humidity from it, making it easier to cope in a hot and humid weather. For example the cold geothermal heat collection circuit fluid can be used as a coolant.

Ventilation replaces indoor air with outdoor air

Ventilation  comes from the Latin ventilationem meaning “an exposing to the air”. Used indoor air is removed and replaced with new and fresh air. A mechanical ventilation system is usually designed and implemented when the house is built or in connection to renovations. Ventilation pipes are installed in the structures and the ventilation unit in a technical space, bathroom, or some other suitable location.

Ventilation removes impurities from the indoor air that are caused by everyday living, such as cooking smells and moisture caused by bathing and the washing of clothes. Emissions caused by building and interior decoration materials are removed at the same time. In addition to being necessary for the wellbeing of the residents and for preserving the structures of the building, ventilation adds to the comfort of living.

Modern mechanical ventilation recovers the heat of the extracted air and uses it to heat the fresh air that is blown into the apartment. This is smart in terms of energy efficiency. Heating the supply air prevents unpleasant drafts. The standard equipment of Vallox MV models include a humidity sensor that measures the relative humidity of indoor air. When the sensor detects excessive humidity, the unit removes it. A carbon dioxide sensor that detects carbon dioxide generated by breathing is available as an accessory. When the level increases too high, the sensor boosts the ventilation.  Usually the ventilation efficiency needs to be boosted after a sauna and showering or when there is a large number of people present in the building. The ventilation efficiency can be reduced when the home is unoccupied.


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