PR2019

To date, the vast majority of indoor air quality studies have relied on repeated visits to dwellings to obtain data derived from short-term monitoring exercises, a time-consuming process that places considerable constraints on personnel, equipment and costs. These studies have focussed on the use of research-grade instrumentation; however, recent developments in the field of consumer-grade indoor air quality sensor technology offers new opportunities.

In 2017 the Danish Building and Property Agency started a project titled “Avoiding energy waste in ventilation systems” by tracking the actual energy use in a sample of their 4 million m2 portfolio of buildings through on-line energy management tools. The project is not complete, but the key preliminary findings  described in this paper are: 

Throughout the certification process of air filters, the major technical characteristics are evaluating. Both theoretical models and experimental methods, proves some relationships between the parameters and the performance of product. In this article we present the statistical analysis of certified products according to EN ISO16890:2016. A sample of 1800 certified products by Eurovent Certita Certification is analysed to highlight products characteristics based on quantitative approach.

In recent years, especially, the climate change (CC) and urban heat island (UHI) effects are becoming serious problems, affecting people’s life and health, especially in hot summer. For large cities such as Tokyo or Osaka in Japan, the UHI effect is particularly intense. It is known that about 40% of urban anthropogenic heat comes from buildings in large cities. To reduce the anthropogenic heat from buildings is an important countermeasure to this problem.  

Upper floors of super-tall residential buildings have different characteristics of the exterior environment as compared to their low floors or low-rise residential buildings due to the high-rise. Upper floors are more affected by direct solar radiation due to the reduced number of adjacent shading buildings and by reflected solar radiation from rooftops. Super-tall buildings also have high level of airtightness because of higher wind speed with high-rise.

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.).