Diagnosis
Stuffy air and high CO2 point to too little fresh air. A demand-controlled system that measures CO2, or balanced ventilation with heat recovery, keeps air quality healthy without heat loss.
Take the ventilation check
Improving indoor air quality
Poor indoor air shows as stuffiness, loss of concentration, headaches and worse sleep. The main indicator is CO2: above 1200 ppm air feels stuffy, below 800 ppm it is healthy.
Fresh air structurally
A demand-controlled system C+ measures CO2 and humidity. A system D with heat recovery brings in fresh air continuously and recovers the heat.
Indoor air
What healthy indoor air means
Ventilation is about invisible air quality. Here is how to recognise healthy values.
CO2ppm
good: below 800attention: above 1200
High CO2 makes rooms stuffy and tiring, often in bedrooms.
Relative humidity%
good: 40 to 60
