English

Energy consumption  in buildings for heating, cooling and lighting needs to be reduced in all European countries in order to achieve the goals set by the latest European Directives  for reducing energy consumption by 20% and increase the introduction of Renewable energy sources by 20%. The present paper focuses initially on the reduction of energy consumption for a university building in Crete and then covering the minimized energy demands with renewable energy sources. The approach is simulation based. At first, current heating and cooling demands of the building are estimated.

The effect of a new passive cooling device to the indoor air is analyzed based both to experimental and simulating results. The tested device is a ventilated pond protected with an aluminum layer, placed on the roof of the examined building. The indoor air temperature of the building has been recorded, before and after the placement of the roof cooling technique. The record indoor air temperature is analyzed, in regard to the ambient conditions.

The experimental analysis aims to investigate ways to protect a water pond, in order to reduce bottom pond temperature. For this purpose, three identical shallow ponds are together recorded in moderate climate. The bottomless ponds are placed on a concrete roof, exposed to the ambient conditions. Water depth is kept constant in 0.10m, while each pond has an area of 1m2. A number of alternative materials for water protection are tested: white textile, the textile used in ironing board, aluminum layer, aluminum foil and insulation.

This paper presents and discusses monitored data of the indoor temperature in almost 50 low income houses in Athens Greece during the winter of 2012-2013. The aim of the research was to identify the degree that the actual economic crisis in the country influences the indoor environmental conditions, comfort and health in low income households. Analysis of the data has shown that indoor temperatures in the monitored low income houses were much lower than the appropriate threshold set for comfort and health.

The solar optical properties of micro- and meso-porous materials that can be building integrated or roof added for evaporating cooling purposes were studied and compared with conventional building materials. The results are interpreted in correlation with their water absorption capacity. For further studying their solar optical properties, absorbance measurements were solar-weighted in accordance with the ASTM G173 standard. Mesoporous materials presented high irradiation absorbance in the IR spectrum with significant variation depending on the water loading at different relative humidity.

The principle of roofs cooling through the water vapour adsorption-desorption cycle in porous materials is presented. In order to study the effect, porous materials of natural origin or synthesized at our lab, were characterized at the micro-scale with SEM, XRD, UV-VIS-NIR spectrometry, thermal and water-vapour adsorption measurements and tested at the urban scale in a wind tunnel of controlled environmental conditions and simulated sun.

This paper aims to present the methodology for the development of a Decision Support System (DSS) that takes into account environmental and socioeconomic criteria, focusing on a case study that was carried out in Athens. The experimental campaign that was performed at city, neighbourhood and building scale and its main results are described. In addition, the results of the Communities of Practice that were organised are reported. A short description of the development of an ANN model for heat island prediction is given.

Clay roof tiles are widely used as roofing materials because of their good mechanical and aesthetical properties. The exposure to atmospheric agents and, most of all, to pollutants and smog affects negatively the solar reflectance of a tile surface. The aim of this study is to analyze the influence of ageing on the solar reflectance of clay roof tiles. We studied samples provided by manufacturer in Greece and USA. Samples were coated with either organic or inorganic coatings.

Scientific evidence exists of an association between dampness and mould in buildings and of an increased risk of health effects for occupants, usually associated with the respiratory system. It is difficult to establish the exact prevalence of residential dampness, but according to WHO, it is likely to be in the order of 10-50%.  

Efforts to save energy may easily lead to the compromisation of indoor environmental conditions and vice-versa. This study suggests an indicator for indoor environmental quality classification, developed with the purpose of assisting households that are trying to save energy, to maintain optimum levels of indoor environmental quality during this effort. The “Dwelling Environmental Quality Index” (DEQI) is a comprehensive indoor environmental quality indicator, reported to occupants as an easily understood number (percentage).