English

Toward the appropriate selection of urban heat island measures technology in the street canyon, the introduction effects of the technologies in the typical street canyon are analysed by the model calculation. It is appropriate to use street trees for the improvement of the thermal environment on the sidewalk and high reflectance paint or water-retentive pavement for the reduction of surface temperature on the roadway. Reduction of solar radiation gain to the sidewalk pavement surface is dependent on the location and area of the shadows by street tree.

Heat recovery ventilation became an unavoidable element of a passive or nearly zero energy building in Northern and Central Europe countries. Airtightness standards became very tight so that the building is compatible with this ventilation system. As frosting of heat recovery unit consumes a lot of electrical energy, a buried pipe system to smooth air temperature variations became also a necessary system in order to avoid defrosting.

With the continuous improvement of the energy performance of buildings, ventilation plays a crucial role in the control of pollutants from indoor sources and related comfort and health effects. However, the ventilation system itself could possibly also be a source of indoor air pollutants such as microbial contaminants. Profound scientific and technical knowledge on the impact of the design, installation and maintenance on the real performances of ventilation systems is currently lacking.

As a consequence of the energy and environmental issues, it is necessary to reduce the energy consumption of buildings. So, the air tightness of building envelopes is being improved and the air change rate due to infiltration is decreasing. It is then even more important than in the past that the buildings are equipped with well designed and working ventilation systems in order that the air renewal within buildings is ensured. In this context, the market of balanced ventilation systems with heat recovery for dwellings is growing. 

Roofs are the envelope component more severely hit by solar radiation in summer (1470 kWh/m2 on average in Italy), hence one may expect that using cool materials on the finishing layer of a roof should provide a significant reduction in the heat flow entering the building, with sensible relief in terms of building cooling load.  In this paper a case study is presented, based on the dynamic simulation of an existing office building in Catania (Southern Italy).

The PerFluorocarbon Tracer (PFT) method is a low-cost method commonly used for measuring air exchange in buildings.  This is a specific instance of the more general  Continuous-Injection, Long-Term Sampling (CILTS)  approach for using tracer gasses. The technique  is widely used but there has been little work on understanding the uncertainties (both precision and bias) associated with its use, particularly given that it is typically deployed by untrained or lightly trained people to minimize experimental costs.

This paper describes part of the research that is being done on the prediction of the performance of light pipes and the ways to optimize their design, in order to house artificial lighting, able to supplement daylight in a space.

There is a growing consensus that the climate is changing faster than at any time in the past millennium. This is likely to have major effects upon many aspects of the built environment. UK Climate Impact Projections 09 indicate significant increases in Summer Mean Temperatures. This may suggest a requirement for cooler buildings during the summer months. In consequence, that would likely lead to an increase in demand for mechanical ventilation and comfort cooling.

The materials that are used in outdoor spaces are of prime importance as they modulate the air temperature of the lowest layers of the urban canopy layer, they are central to the energy balance of the surface and they form the energy exchanges that affect the comfort conditions of city people. Paved surfaces contribute to sunlight’s heating of the air near the surface. Their ability to absorb, store and emit radiant energy has a substantial affect on urban microclimate.  

In order to improve the quality of ventilation systems, assessments are widely used. In this paper, 3 main assessment levels are distinguished based on the number of ventilation systems to be assessed and the assessment objective.