In the Group of Building Environmental Studies different scientific activities are carried out, involving many aspects of building components and researching new techniques. The current research topics are listed as follows:
- 1Passive Cooling: Research on passive cooling of buildings focus on the development of techniques, systems and tools to provide thermal comfort during the summer period. The group has undertaken the coordination of the PASCOOL European Research Program, (1992- 1996). The Group has developed algorithms and tools, (SUMMER), to calculate the specific performance of passive cooling techniques as applied to buildings. Considered techniques involve solar control, buried pipes, evaporative cooling, radiative cooling, night ventilation, etc.
- 2Energy Rehabilitation: Research on energy rehabilitation of buildings focuses on the development and the evaluation of the energy potential of different techniques and systems to improve the thermal and visual performance of buildings and decrease their energy consumption.
Energy and Environmental Rating Techniques to evaluate the efficiency of the different retrofitting techniques have been developed. The group has undertaken the coordination of the OFFICE European Research Program while participates in the MUSEUMS Rehabilitation Program.
- 3Energy classification of buildings: Energy classification techniques for buildings involving experimental and theoretical protocols have been developed by the group. Specific energy homogenisation methodologies have been created as well. The Group has undertaken the coordination of the EUROCLASS European Program that has developed monitoring protocols and theoretical rating techniques for residential buildings, while participates in the EUROPROSPER Program that prepares rating methods for offices.
- 4Development of solar components: Design, Testing and Optimisation of Intelligent Solar Components is an important part of the group’s research. The AIRLIT-PV as well as the SOS intelligent solar components have been tested and optimised by the group, in the frame of various European research programs.
- 5Thermal comfort: Alternative Thermal Comfort methods and tools, especially for the summer period, have been developed and tested by the group in the frame of the PASCOOL and SCATS European research programs. Tenths of buildings have been monitored and hundreds of people has participated in the research.
- 6Heat Island Effect: Heat island phenomenon in Athens is measured since 1996. Twenty three stations have been installed in and around the city, measuring the urban temperature in an hourly base. In parallel, a mobile station is used for specific monitoring of the heat island. It has been found that the heat island intensity can be as high as 14°C. Important spatial and temporal variations have been identified and documented. Studies involving statistical analysis and intelligent prediction techniques have been carried out. The energy impact of the heat island phenomenon has been calculated and it is found that it considerably increases the cooling load of buildings, as well as the peak electricity load while it significantly decreases the efficiency of air conditioners.
- 7Canyon Effect: The air flow and temperature distribution in urban canyons has been investigated through specific experimental and theoretical actions. Experiments of three or more days have been performed in 15 canyons, using the mobile monitoring station and other equipment. The overall work has been undertaken in the frame of the POLIS and URBVENT European research projects. Based on the experimental data, specific theoretical prediction models have been developed for the air flow, as well as the air and surface temperature distributions in urban canyons.
- 8Micro-climate Improvements: Specific research actions have been carried out to develop, evaluate and apply techniques that improve the urban micro-climate. Studies concentrate on the use of cool materials, vegetation, use of heat sinks, etc. Studies have been carried out for the Olympic Village of Athens, Western Athens major area, Keramikos area, etc. The impact of various alternative materials for streets and pavements has been studied experimentally and in details using infrared thermography.
- 9Urban Cooling Strategies: Specific research has been carried out through the URBACOOL program, to develop, test and evaluate the potential of alternative cooling systems and techniques for cities. Studies included district and central cooling techniques, demand side management, advanced air conditioning, etc.
- 10 Natural ventilation: Heat and mass transfer phenomena through large openings have been extensively studied both experimentally and theoretically. Network and intelligent fuzzy logic techniques to predict the air flow through large openings have been developed and validated. In parallel the air flow and heat transfer phenomena through large horizontal openings have been the object of theoretical and experimental research. The group has developed the network AIOLOS software tool to predict air flow in naturally ventilated buildings.
- 11 Hybrid ventilation: Hybrid ventilation techniques are studied in real buildings in the frame of the RESHYVENT European Project as well as in the frame of the Annex 35 of IEA. Studies concentrate on the potential of hybrid ventilation techniques in urban environments and in particular in deep canyons.
- 12 Indoor Air Quality: Detailed Indoor Air Quality Studies have been carried out in hundreds of buildings, such as offices, schools, commercial and residential buildings. All studies involved measurement of pollutants, ventilation measurements and study of specific solutions to improve the indoor air quality.
- 13 Simulation of Building’s Energy Efficiency: The Group has advanced capabilities of simulation of the thermal performance of buildings. In particular the group is able to simulate, using advanced thermal and aerodynamic simulation tools, the following building components :
a)Microclimate around the building, temperature and wind distribution, thermal comfort and use of cool materials, green components , etc
b)Building envelope, including opaque and non opaque components
c)Indoor Environment including thermal comfort conditions and simulation of all parameters
d)Energy consumption of buildings for heating, cooling, lighting and hot water
e)HVAC systems performance
f)Daylight and artificial lighting
g)Indoor air quality and concentration of indoor pollutants
h)Natural , Mechanical and Hybrid ventilation
i)Passive Components including passive heating and cooling systems