Indoor air and carbon dioxide

High levels of indoor carbon dioxide cause fatigue, headaches and difficulty concentrating. Stale air is often a sign of insufficient ventilation.

The smart TopAir ventilation solutions of Entos Oy measure indoor CO2 levels and ventilate the space as needed, ensuring fresh air 24 hours a day.

Most of indoor CO2 is emitted by humans through breathing. Other sources of CO2 in households are pets. In residential apartments, CO2 levels increase significantly in bedrooms during night time. In other types of premises, CO2 levels are linked to the occupancy rate of the room. In school classrooms, CO2 levels rise during lessons and in day care centres, the levels go up in nap rooms during naptime.

High CO2 levels have a significant effect on indoor air quality. The action level for CO2 is 1,150 ppm higher than the CO2 content of outdoor air, which is 400 ppm on average.

The following limits have been determined for indoor air (ppm = parts per million):

• under 800 ppm = Good indoor air quality
• 800–1,200 ppm = Air feels stuffy
• over 1,200 ppm = Poorer ability to concentrate, headaches, fatigue.

People react very differently to growing CO2 levels as the ability to tolerate high CO2 content varies. Most people sense the staleness of the air, feel fatigued and have headaches. In schools and workplaces, high indoor CO2 levels also affect concentration, efficiency and quality. A night of poor sleep might be caused by high indoor CO2 levels in the bedroom. When CO2 is absorbed in the bloodstream, it causes restlessness, sweating and waking up in the middle of the night.

CO2 level as an indicator of sufficient ventilation

There are many kinds of indoor air quality monitors available on the market. Indoor air quality monitoring can reveal elevated CO2 levels even in spaces where the indoor air quality is supposed to be good. High CO2 levels can be decreased with increased ventilation and fresh make-up air.

However, if the occupancy rate of the room changes unexpectedly, normal scheduled ventilation timers are not enough to keep the indoor air fresh and clean. Unexpected changes in the occupancy rate can be the result of teleworking, shift work and parties, for example. During this exceptional time, people have stayed at home more and as a result, the need for sufficient ventilation has increased as well.

Smart indoor air quality management

Smart ventilation reacts to the apartment’s CO2 levels: it boosts ventilation progressively when a certain CO2 limit is exceeded and reduces power when the levels start to go down. The system boosts ventilation when necessary, but does not cause draft in the apartment. Traditional ventilation fans can cause draft as they only have two power settings, 50% or 100% ventilation. When running at full power, this type of ventilation fan is very noisy. At night, continuously adjustable smart ventilation is a more pleasant option.

Smart ventilation sensors constantly keep track of the quality of indoor air to maintain low CO2 levels both at home and in the office, 24 hours a day. Fresh and clean indoor air improves the quality of sleep and helps you concentrate on your tasks.