English

Urban heat island (UHI) phenomenon has been observed in many populated cities located in cold regions (e.g., Montreal in Canada) during summer. One of the well-known strategies to mitigate the temperature rise of urban areas is increasing their albedo. Roofs cover about 25% of urban areas and increasing their reflectivity would have significant effect on the total energy budget of a city. Changing the surface energy budget can directly affect the air temperature near ground and the vertical wind speed.

Rejection of solar gains is the aim of passive cooling strategies in any type of building and any climatic region. The extent of cool materials usefulness is dependent on the severity of external conditions and internal heat gains. The aim of the present paper is to underline the contribution of an innovative cool fluorocarbon coating in the reduction of energy demand for cooling in an industrial building with increased heat gains under temperate climatic conditions. The material is tested using accelerated weathering procedures and its optical properties, i.e.

We have developed a new evaluation method of “thermal radiative power” (TRP) for investigating the impact of building surface material albedo on urban environment. The simulation system ENVI-met is used. This system is a 3D computer model which analyzes micro-scale thermal interactions within urban environments. It simulates urban-scale environmental conditions such as roofs, exterior wall, and ground surface temperatures. Focuses of this research are on the climate change in urban and community scale in cold climates.

The present study deals with the feasibility of Flywheel Energy Storage Systems (FESS) in several RES-based stand-alone electricity production systems. Energy buffering is necessary in any RES-based off-grid system, however conventional energy storage systems (batteries, hydrogen etc.) suffer from limited equipment lifetime, high initial costs, and negative environmental impact during their operation as well as after their life-cycle.

Fuel cells are highly efficient energy conversion systems that have recently gained significant interest in terms of both science and applications. Exergy analysis is adopted here for a power plant involving SOFC with external steam reforming that is fuelled by modeled biogas/steam mixtures. The electrical efficiency has been estimated and the effect of various operational parameters on the process efficiency has been investigated.

Heat island which is the most documented phenomenon of climatic change is related to the increase of urban temperatures compared to the suburban. Among the various urban heat island mitigation techniques, green and cool roofs are the most promising since they simultaneously contribute to buildings’ energy efficiency. The aim of the present paper is to study the mitigation potential of green and cool roofs by performing a comparative analysis under diverse boundary conditions defining their climatic, optical, thermal and hydrological conditions.

The need for more energy efficient Heating Ventilation and Air Conditioning systems led to a search for new systems for heating, cooling and ventilation of buildings. Strong reduction of energy consumption within the built environment is necessary because of the growing effects of depletion of fossil fuel and global warming. This lead to a almost standard concept of energy efficient office buildings in the Netherlands. That concept exists of heat pumps and  LTES aquifers combined with thermally activated building systems (TABS).

In a Dutch project the double façade became an integral part of the ventilation concepts aa well as the heating system by trying to optimize the heat gain within the cavity during spring and autumn. The study shows how variable facade parameters influence the energy flows coming through the facade, in order to optimize the indoor environment for the comfort of the individual occupant. How can the facade make optimal use of the free incoming energy flows to maximize the comfort level of the individual building occupant at minimal energy use?

The aim of this paper is to experimentally investigate and analyze the thermal and optical behavior of a Green Roof System (GRS) installed in the 10000 m2 roof of a fully insulated, bioclimatic office building in Peania. More specifically, during the experimental procedure, measurements of the outdoor temperature and relative humidity have been performed, as well as of the air temperature inside the building and the surface temperature of the ceiling.

Cool roof coatings remain cooler than absorptive roofs and thus predominantly are used in buildings that require the reduction of the indoor temperature and the cooling loads. Cool roofs can also reduce the ambient temperature. A currently contentious aspect of solar reflective cool coatings is the extent to which an initially high solar reflectance decreases with time.