With heat waves becoming more frequent in recent years, it is crucial to understand the challenges of thermal comfort in order to enjoy comfortable buildings in all seasons. Whether in RE2020 construction or renovation, buildings with optimized thermal comfort consume less energy in winter and summer and are much more comfortable. So what are the six key parameters that define thermal comfort?
1. Ambient temperature:
Ambient temperature is probably the best-known parameter of thermal comfort. It refers to the measurement of the heat of the ambient air. To ensure comfort, the ambient temperature must be adapted to the needs of the building's occupants.
While ambient temperature plays a key role in thermal comfort, perceived temperature is also essential. This corresponds to the average of the interior temperatures of the walls (ceiling, walls, floor) and the air temperature.
Perceived temperature must be between 19°C and 24°C to ensure good thermal comfort.
2. Humidity:
Humidity also plays an essential role in thermal comfort. High humidity levels can cause discomfort and promote the growth of pathogens. Conversely, humidity levels that are too low can dry out the respiratory tract and skin. It is therefore recommended to maintain relative humidity between 40 and 60% for optimal comfort.
3. Air movements:
Air movement is an often overlooked factor, but it can have a significant impact on thermal comfort. Excessive air movement can cause uncomfortable drafts, while insufficient air movement can make a room feel stuffy. That's why it's important to adjust air circulation to avoid these problems.
4. Air quality:
Indoor air quality is essential for the comfort and health of occupants. High levels of pollutants such as volatile organic compounds (VOCs) or fine particles can cause respiratory problems and headaches. It is therefore necessary to have adequate ventilation and to control sources of pollution in order to maintain good indoor air quality.
5. Thermal radiation:
This concept refers to the exchange of heat between surfaces, particularly between human bodies and surrounding objects. The temperatures of surrounding surfaces can influence our perception of heat or cold (this is known as the perceived temperature). As a result, factors such as the thermal insulation of walls, windows, or the materials used can have a significant impact on thermal radiation.
6. Physiological comfort:
Finally, a subjective criterion also comes into play in the concept of summer comfort: the physiological factors of the building's users. Depending on their metabolism, age, clothing, and physical activity, for example, occupants will not all have the same perception of thermal comfort in the same building. Although this criterion varies from one individual to another, it must still be taken into consideration.
For building professionals, considering the six parameters of thermal comfort is essential to creating a pleasant environment in all seasons. Temperature, humidity, ventilation, air quality, thermal radiation, and physiological comfort are interdependent factors that must be taken into account to optimize occupant comfort in both winter and summer. While these factors are taken into account in RE2020 construction, they can sometimes be difficult to adjust in renovation projects.
These parameters may vary depending on the context and individual preferences. It is therefore important to choose solutions that are tailored to each project.
