English

Wood construction presents numerous advantages on the environmental impact. Envelopes of wood frame houses already have air gaps. We wish to use them in systems aiming at to reduce the energy loads in winter and to improve the thermal comfort in summer. We so decided to couple a faade integrated solar air collector with a heavy and ventilated internal wall. The envelope of wood frame houses being light, it is possible to store solar energy in the internal wall.

In idyllic ATHENS of the 5th century B.C. while gazing out at the Aegean Sea, ARISTOTLE codified the theory of the presocratic philosophers on the value of the 4 basic elements FIRE(SUN), AIR. WATER, EARTH and the 4 basic qualities WARM-COLD, DRY-WET.

In the 6th Framework Programme of the European Union, Politecnico di Milano is participating in an Integrated Project related to energy and environmental efficiency in buildings. This project (BRITA in PuBs) aims to increase the market penetration of innovative and effective retrofit solutions to improve energy efficiency and integrate renewables in buildings. The project includes exemplary retrofit of 9 demonstration public buildings in the four participating European regions (North, Central, South, and East).

Cooling buildings, more than a generalized need, is a reason for concern because of a paranoia provoked inter alias by an aggressive marketing of HVAC, relatively inexpensive equipment and the anticipation stimulated by the media of climate change effects. But, as a matter of fact, there are many and, in some cases, sound reasons for cooling buildings. The purpose here is to propose to discuss the cooling issue starting from the point that there is not a general need for cooling everywhere in the World.

This paper summarises a series of design proposals, which aim at exploring in an architectural way, the implementation of PDEC in the urban open spaces of Athens. These design proposals refer to the larger scale of the typical urban block, as well as the intermediate scale of the urban square, and attempt to increase convective and evaporative cooling within the dense city fabric. For a city with a hot and relatively dry climate, like Athens, the effect of enhanced air circulation at pedestrian level can significantly improve thermal conditions during the summer.

A multi-stage down-draft evaporative cool tower (DECT) was developed as an improvement to an existing single-stage design. The new tower incorporates a secondary air inlet, added to increase the cooling output and reduce the water consumption in a tower of given cross-section and primary inlet geometry. The secondary air, which may be drawn from the interior space being cooled, is cooled by evaporation in the lower section of the tower.

A multi-stage down-draft evaporative cool tower (DECT) was developed as an improvement to an existing single-stage design. The new tower incorporates a secondary air inlet, added to increase the cooling output and reduce the water consumption in a tower of given cross-section and primary inlet geometry. The secondary air, which may be drawn from the interior space being cooled, is cooled by evaporation in the lower section of the tower.

To evaluate wind pressure distribution on a building by using CFD (computational fluid dynamics), it has been generally practiced to use k-? models. However, it is known that the use of the standard k-? model has disadvantages such as overestimation of wind pressure coefficient and turbulent kinetic energy on the windward surface where wind impinges on the building. To overcome these problems, various modifications of the k-? model have been proposed. In the present study, a number of modified k-?

The purpose of this paper is to provide a multicriteria approach in order to develop and to assess several architectures of controllers for hybrid ventilation. Indeed, there is nowadays a great interest in hybrid ventilation as an energy efficient strategy to achieve thermal comfort and indoor air quality. To reach those targets and manage hybrid ventilation systems, advanced control strategies based on hierarchical fuzzy controllers have been therefore developed at the LASH laboratory.

One of the first passive energy standard office buildings in Europe was extensively monitored to analyse the summer performance of highly insulated, well sun-shaded and mechanically ventilated buildings. During typical German summer conditions with less than 160 hours outside air temperatures above 25C these buildings perform excellently during summer, even if the internal loads are rather high. If ambient air temperatures are significantly higher like in summer 2003 with more than 3K higher average temperatures, nearly 10% of all office hours are above 26C.