Temperature is one of the main factors of how we experience the indoor climate.
We often talk about the range of different temperatures when indoors, it can be either too hot, or too cold or maybe just right.
Dry temperature is what we usually talk about as temperature and which is measured with a standard thermometer. We can also describe the temperature as 'hot and muggy' or a hot heat - these decsriptions have a lot to do with the humidity as much as the temperature.
Humidity is one of the most important indoor parameters that affects our air quality as well as the well-being and health of people in indoor environments. Moisture, particularly in cold climates, is most often related to problems such as moisture damage with mold and bad smells. This is caused by poor ventilation that creates too high humidity.
Low humidity also creates problems especially for people such as dry eyes, dry skin, dry mucous membranes and some seasonal infection such as influenza.
For example, in Nordic climates, the indoor humidity is often as low as 5-20%, this is considered extremely dry and has a negative effect on our well-being and health. Science says that an optimal indoor climate should have a relative humidity (RH) between 30-60%.
There are many sources of pollution inside a building, and to ensure a healthy indoor climate, the pollutants need to be transported out with efficient ventilation and replaced with fresh air. The pollutants are added to the indoor air from things such as furniture, building materials and electronics - but we humans also pollute the air around us.
80% of the world's population lives in areas where the WHO reccommended values for air pollution are exceeded. By filtering the supply of air into the buidling, the amount of harmful particles is reduced thus improving the health of building occupants.
To measure is to know
Air quality is an area with many different aspects and it may seem difficult to grasp, but a good start is to measure and monitor the air quality, so the ventilation can be adapted accordingly.
A common metric is the CO2 content, which has the advantage that it is easy to measure, quantify and set limit values around. But if you measure CO2, you capture certain important aspects that mainly affect the level of performance, but you can miss other health aspects. Instead, measuring and ventilating based on VOC concentration captures a wider spectrum of potential problems.