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The perimeter space near windows usually has some problems with the thermal environment which is easily affected by heat transfer and radiation from windows. Compared to interior space of the room, the airflow in this area usually has different characteristics due to the effect of buoyancy, thus it may reduce thermal comfort of perimeter space. To improve the thermal environment in perimeters, breeze line diffusers are widely used in Japan as the terminal equipment of air conditioning and ventilation systems. This diffuser is the same as so-called ceiling slot diffuser.

Addressing the airtightness of the building envelope is key to achieve thermal comfort, good performance of ventilation systems and to avoid excessive energy consumption. Previous studies have estimated an energy impact on infiltration on the heating demand between 2 and 20 kWh/(m2·y) in regions with temperate climates. In Spain, this issue has not yet been addressed in depth. This study aims to assess the energy impact of uncontrolled air flows through the building envelope in residential buildings in Spain.

Between 2017 and 2018, the Centre for Studies and Expertise on Risks, the Environment, Mobility and Planning (Cerema) organized an airtightness measurement campaign in 117 multi-family collective and single-family French dwellings. These dwellings were built before 2005, that is, before the release in 2005 of the fifth French thermal regulation for new dwellings, that was the first to introduce specific requirements for airtightness.

The trend in European countries, such as Belgium, France and Germany is that the quality of the airtightness of the building envelope is getting better and better. This is true for small, airtight apartments, Passive houses and some large buildings with an excellent airtightness due to special requirements, e.g. oxygen reduction or fire protection.

Across different territories there are various normative models for assessing energy demand of domestic dwellings, which use simplified approaches to account for the heat loss due to the air infiltration of a building.  For instance, the United Kingdom uses a dwelling energy model, known as the Standard Assessment Procedure (SAP), and this utilises a process where the measured air permeability value (q50), is simply divided by 20 to provide an infiltration rate (subsequent modification factors are then used for factors such as sheltering etc.).

Buildings represent approximately 40% of global energy demand and heat loss induced by uncontrolled air leakage through the building fabric can represent up to one third of the heating load in a building. This leakage of air at ambient pressure levels, is known as air infiltration and can be measured by tracer gas means, however, the method is disruptive and invasive. Air infiltration models are a non-disruptive way to calculate predictive values for air infiltration in buildings.

This study used a mathematical model to explore the accuracy of extrapolating multi-point blower door test results down to lower pressures at which building infiltration usually occurs naturally.  The mathematical model was applied to leaks of five different widths.  The leakage of the five different widths was then combined in different distributions to simulate total building leakage.  The calculated total building leakage was then compared to an extrapolation from the test pressures using a power law curve fit.

The impinging jet ventilation system (hereinafter referred to as IJV) has been proposed as a new air conditioning ventilation system. Properties of indoor environment with this system using impinging jet are complicated. The present paper reports fundamental properties of indoor air with distributed interior heat generation load assuming an office. The experiment was conducted in the climate chamber of which floor area was 27.0 m2, and basic properties of temperature and CO2 distributions were investigated.

Ventilative cooling can be used as a passive cooling measure to reduce the cooling energy demand of buildings. It can be used during the day, directly removing excessive heat gains, or during the night (i.e. night flush), in which cold outdoor air flows through the building and cools down the indoor air volume and subsequently the thermal mass of the building. Night flushing reduces the indoor air temperatures at the beginning of the next day and the cooling demand over the day.

The outdoor climate is changing and the airtightness and insulation levels of residential buildings are improving. During the warmer season this can lead to overheating problems, especially when the house is situated in urban areas. In order to reduce overheating problems, ventilative cooling can be used to keep the indoor conditions at a comfortable level. Natural ventilation is not always a feasible solution, for the risk of burglary, and when the outdoor temperatures are not suitable for cooling the house, for instance in urban heat islands.