Airbase publication

Nowadays, due to climate change, heatwaves become stronger in terms of frequency and intensity. This phenomenon can have serious impact on the indoor environments, indoor thermal comfort and on public health. These situations of high indoor thermal conditions can expose the occupants to health risks such as hyperthermia, dehydration, and heat strokes. Then, the estimation of these risks is crucial. The currently used indices to estimate health risks such as WBGT, HSI and PHS are generally dedicated to outdoor environments and for subjects exerting heavy activities.

Building ventilation demand increased during the “new normal” following the Covid-19 pandemic. Rather than completely renovating existing HVAC equipment, it is more practical and cost-effective to maximize their existing ventilation performance. This study focuses on slot line diffusers, which are widely used for handling perimeter heat loads. Its long throw distance and wide coverage effectively block cold drafts and heat flow from the exterior window glass.

In recent years, earth-to-air heat exchanger (EAHE) systems, which is a method of pre-cooling and pre-heating outdoor air with earth-to-air heat, have been attracting attention as one of the technologies to achieve ZEB. However, at the operational phase, in order to achieve both energy saving and suppression of dew condensation control, EAHE control methods such as the timing or amount of outdoor air introduction have not been established.

The accurate estimation of the local wind pressure coefficient is crucial in the numerical modeling of natural or mixed ventilation in buildings subjected to wind. Building ventilation modeling typically relies on average wind pressure coefficient values specific to the building façade and wind direction. While the literature provides some correlations and standards for building wall-average pressure coefficients, these values are only useful in the absence of additional information or a database, as they can vary significantly based on urban forms.

The progressive increase in the global average outdoor air temperature has caused an increase in the cooling demand in buildings in recent years. Given this climate change scenario, there is a need to develop efficient air-cooling systems that improve the energy efficiency of traditional direct expansion units. In this sense, ventilative cooling technologies should be tested under the climate change world scenario.

This study investigates the impact of lowering temperature setpoints on occupants' thermal comfort in office buildings, prompted by government initiatives in Europe, including the Netherlands, to reduce energy consumption. The research methodology involved a case study conducted in three office buildings in The Netherlands. Data on occupants' perception, motivation, clothing thermal insulation, activity level, discomfort, and thermal control options were collected through interviews conducted for thermal comfort surveys and building surveys.

Sea Water Air Conditioning (SWAC) is a highly efficient alternative to conventional air conditioning that uses deep seawater as a cooling source (Free Cooling). There are three SWAC installations in the world dedicated to cooling production in real-operating conditions, all located in French Polynesia due to its suitable bathymetry for SWAC installations and the high cooling needs of tropical climate. These installations provide cooling for two hotel complexes and a hospital center respectively in Bora Bora, Tetiaroa, and Tahiti.

Elderly people residing in nursing homes spend a vast majority of their times indoors and often in common recreation areas, to allow for socialization and interaction. Elderly people are a vulnerable age group. Hence, it is essential to provide them with good breathable air quality during these common activities and reduce cross contamination through ventilation. Prolonged exposures of elderly to contaminants may adversely affect their health, quality of life and increase medical expenditures due to frequent hospitalizations.

In office buildings, an air-conditioning system with natural ventilation can reduce cooling loads and create a comfortable indoor environment. However, it is difficult to predict the performance of such systems and there is concern that the natural ventilation will create an uneven indoor thermal environment. In this paper, we propose a method for evaluating the performance of a natural-ventilation air-conditioning system by coupling a building energy simulation tool and computational fluid dynamics.

Since the spread of covid-19 in 2019, it is necessary to realize an indoor environment that takes measures against viral infections such as covid-19 and influenza virus. One method for realizing such an indoor environment is to control indoor humidity. In a high-humidity environment, mold grows, indoor air quality deteriorates, and physical fatigue increases. On the other hand, in a low-humidity environment, viruses easily suspend and the immune system gets weaker. Therefore, controlling indoor humidity is necessary for human health.