An urban heat island (UHI) is an increase in air and surface temperatures in city centers compared to neighboring rural or forested areas, particularly at night.
Causes
This phenomenon is due to the way cities are constructed (asphalt, dark roofs, lack of vegetation, dense human activity), which reduces air circulation and causes high heat absorption during the day, which is then released at night. The temperature can reach up to ten degrees higher than in surrounding areas, especially during periods of intense heat.
An example of the UHI rate in the 9th arrondissement of Paris:
Source: https://www.construction21.org/france/articles/h/paris-icu.html
The consequences
These heat domes covering urban areas can cause thermal discomfort and have a significant impact on human health and energy consumption in urban areas. This phenomenon is getting worse over time. To remedy this, it is necessary to increase the albedo of surfaces and increase the greening of buildings and urban spaces.
Our expertise:
THEMACS Ingénierie offers rapid characterization of the albedo of your materials and surface coatings in order to reduce surrounding heat islands. To do this, we measure spectral emissivity and characterize the albedo on different surfaces using our portable albedo measurement device, which we have developed ourselves.