Summer comfort

Due to global warming, severe problems of buildings overheating during summer in temperate and hot climates arise. Thus, there is an increasing use of air conditioning. However, alternative passive and soft cooling systems exist to address comfort and energy savings issues, such as natural ventilation or ceiling fans, that consume less energy. Although they are well-known today, their use remains under-enhanced.

Recent studies have shown that ventilative cooling reduces overheating, improves summer comfort and decreases cooling loads. Therefore, it is considered as one of the most efficient way to improve summer comfort. Although, HVAC designers still lack of guidelines to improve the energy and comfort efficiency of their installations.  

This article deals with summer comfort and room air distribution in low-energy housings. In such buildings, the efficient thermal insulation and air tightness make it crucial to efficiently dispose of the heat released by the internal gains. In this prospect, the comfort in a test room resulting from an integrated cooling and ventilation system is assessed both experimentally and numerically. The air is supplied into the room close to the ceiling through a wall-mounted diffuser of complex geometry composed of 12 lobed nozzles.

The objective of this study was to develop a method for hourly calculation of the operating temperature in order to evaluate summer comfort in dwellings to help improve building design.

In this study, an attempt is made to define building design variables for a medium-sized office building with individual office cells in order to provide sufficient summer comfort without active cooling in a moderate climate.
Firstly, an approach to take realistic window-opening behavior into account is proposed based on observational data in literature. A stochastic model is defined for an active and a passive user, representing the variability between individuals.

Several high schools in the south east of France are subject to a major work of renovation. These works need to take into account the problem of summer comfort for a better well-being and intellectual performance of students. One of it was chosen to carry a study on the specific constraints for achieving summer comfort. The study consists of surveys, monitoring and simulations. This enables to determine the major causes of the summer discomfort in field and to propose several passive solutions. These solutions were assessed by simulation using a dynamic simulation tool.