Airbase publication

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).

Climate change phenomena such as global warming and urban heat island effects cause serious problems for the development of building technology. Therefore, it is imperative that architects and designers consider the effects of climate change on long-term building performance. At present, energy simulations are often used to evaluate the indoor thermal environment and energy consumption of buildings. In these simulations, it is common to use regional weather data that are usually based on current or past weather conditions.

As environmental issues are rapidly gaining more and more interest globally, various measures and standards are being set to minimize the use of energy in the architecture field, which consists about a fourth of the total use of energy. Korea, like other developed countries, is also aiming to make zero-energy buildings mandatory(by 2025) implementing various measures such as energy efficiency rating system and energy performance certification systems to gradually minimize energy consumption in buildings. 

The paper deals with the investigation of air flow field in front of the reinforced slot exhaust hood with the workbench at the level of the lower edge of the exhaust opening. The reinforced exhaust hood, which is also known as the Aaberg exhaust hood, is the traditional exhaust hood equipped with an air supply jet that intensifies exhausting along the axis of the exhaust hood. By an adjustment of the air supply quantity, the reinforced exhaust hood can operate in traditional or reinforced modes.

Future climate change might have a tremendous impact on energy use, ventilative cooling strategies and thermal comfort in buildings, since these parameters are strongly correlated with the external weather conditions.
This paper will present results of a study of the impact future climate change scenarios as developed by the Intergovermental Panel on Climate Change (IPPC) and implemented in weather files for specific future time slices (2020, 2050 and 2080) on the design of the external envelope of a hotel building in Greece. Three climatic regions of Greece are considered.

A large number of indices have been developed to assess human bioclimatic conditions. The indices that could be considered valid in all climate and seasons are those that are based on calculations involving the heat balance equation. The aim of the present study is to evaluate the performance of selected existing indices based on body’s energy balance, in an outdoor built environment. A field questionnaire survey was carried out simultaneously with microclimatic measurements in a street canyon located in the centre of Athens, Greece.

Utilizing a cool roof is an efficient way to reduce the cooling energy use of a building. Cool roofs, however, may increase heating energy use in winter. In cold climates, during the winter the sun angle is lower, days are shorter, sky is cloudy, and most heating occur during early morning or evening hours when the solar intensity is low. In addition, the roof may be covered with snow for most of the heating season. All these lead to a lower (than what is commonly thought) winter time heating penalties for cool roofs. 

The nighttime ventilation strategy uses the outdoor cold air during the night to cool the building mass. The cooled building mass then is used as a heat sink during the next hot day. Mechanical nighttime ventilation requires a fan for the outside air ventilation. The energy use by the fan reduces the potential cooling energy savings. Higher nighttime ventilation flow rate and its duration decrease required cooling energy during next hot day in the building, also they increase fan energy consumption.