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Showing papers by "Savvas A. Tassou published in 2008"


Journal ArticleDOI
TL;DR: In this paper, an analytical model is developed to characterize the radiative transport process in highly porous, open-celled metal foams having idealized cellular morphologies in terms of fundamental radiative parameters such as emissivity, reflectivity and configuration factors.

105 citations


Book ChapterDOI
01 Jan 2008
TL;DR: In this paper, the authors discuss the types of refrigeration systems used in supermarkets and their environmental impacts due to energy consumption and refrigerant leakage and identify the ways in which these impacts can be reduced.
Abstract: Publisher Summary The modern supermarket depends on electricity for lighting, ventilation and, above all, refrigeration to protect a vast selection of meats, dairy products, fruits, and vegetables. Supermarkets are among the greatest single end-users of electricity with typical annual electrical energy consumption in the region of 1000 kWh/m2 sales area. The refrigeration systems account for between 40 and 50 % of the electricity used, whereas lighting accounts for between 15 and 25 % with the Heating, Ventilation and Air Conditioning (HVAC) equipment and other utilities, such as bakery making up the remainder. All refrigeration systems have the potential to leak because pressures in the system are usually many times higher than atmospheric. It is estimated that between 10 and 30 % of the refrigerant charge in large systems is released to the atmosphere each year, contributing to the depletion of the ozone layer and to global warming. Refrigerant loss also contributes to the reduction of the operating efficiency of the system, leading to increased power consumption and greenhouse gas emissions, higher maintenance costs, and eventual system failure. This chapter discusses the types of refrigeration systems used in supermarkets and their environmental impacts due to energy consumption and refrigerant leakage and identifies the ways in which these impacts can be reduced.

15 citations