Indoor parameters - What to know?

From: Velichkova, R., Stankov, P., Angelova, R. A., Simova, I., & Markov, D. (2019, September). Influence Of Indoor Pollution And Parameters On Human Health. In CBU International Conference Proceedings (Vol. 7, pp. 1015-1019).

The internal balance of the human body, including the thermophysiological balance, is largely dependent on external conditions. The microclimate of the room in which a person is located for a long time plays a significant role in the formation of immunity, efficiency, the ability to relax and unwind comfortably. The state of the internal environment of the building can not only fruitfully affect human health but also have a negative impact. Thus, the longer people stay in a non-ventilated room, the more the room affects the proper work of the body.

The microclimate of any premises is characterised by air temperature, relative humidity and air velocity.

1. The temperature of the room is the most important indicator of comfort. The relative humidity also depends on the temperature. Low temperatures provoke the release of heat by the human body, which requires thermophysiological reactions, many of them related to discomfort, detention of reaction, sleepiness, and increment of the mistakes. If a low-quality heating equipment is installed in the room, then people will constantly suffer from cold related discomfort and diseases (cold, cough, proclivity to infections).

High temperatures (over 27 °C) in the indoor environment also provoke problems, related to the thermophysiological reaction of the body. The release of the excessive heat is accompanied by removing salt from the body. The joint effect of the thermophysiological responses and the changes in the water-salt balance leads to a different impediment of many systems in the human body. The result is thermal discomfort, decreased attention and an increase in mistakes.

2. Relative humidity of indoor air is a factor that depends, to a large extent, on temperature. If there are no installed humidifiers in the room, then the higher the temperature, the drier the air will be. A healthy person, once in a room with dry air, will feel discomfort in 10-15 minutes. If a person has a cold, he will cough. Moderately moist air (40-60%) will create comfortable conditions for work and rest. In winter, it helps to strengthen the immune system, as it does not allow the mucous to dry out and become vulnerable to viruses. In the summer, with comfortable humidity, it is easier to tolerate heat, maintain healthy skin, etc.

3. The velocity of the air is a factor of the microclimate that affects the body in different ways. For example, at temperatures up to 33-35 °C, the air velocity of 0.15 m/s is accepted as comfortable, since the air has a refreshing effect. In a temperature environment of above 35 °C, however, an opposite effect of discomfort appears for the same value of the air velocity