Airbase publication

Air quality in the office room areas, as well as their energy demands for heating and cooling are directly depended on the ventilation levels in those rooms. Specifically, high internal air quality requires high levels of ventilation and therefore high energy demands. On the other hand, high energy savings can be accomplished by full building impermeability, which means low to none ventilation and at the same time low air quality.

This research studies the possibility of introducing combinations of specific mitigation techniques for the urban heat island effect (UHI) in Athens, Greece. A variety of factors, such as surface cover, dense traffic, anthropogenic heat release and urban characteristics including geographic features and climate conditions interact with one another to create UHI, which is becoming increasingly evident also due to the changing climate, which in this region is expected to increase the duration of hot spells and the frequency of heat waves.

Urban gardens are a means of greening and are created by a local community. As regards any urban environment, urban greening helps cooling the air and provides shading, thus reducing building energy consumption and improving the outdoor conditions during the summer. In more detail, vegetation is a way to deal with the phenomenon of energy poverty in which many people cannot meet their basic energy needs as well as the phenomenon of urban heat island. This paper deals with the ways in which vegetation affects the improvement of microclimatic change, mainly through evapotranspiration.

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.