District cooling, a technology with great potential of application

During the last decades, it has been observedthat the annual electricity consumption rose, especiallyduring the summer periods. It also hasreached high levels, due to the increased demandof air conditioning and refrigeration,mainly with electric systems. These systems,despite of the utility that they offer for the reductionof the thermal loads and the produce ofcooling energy for industrial uses, are not costeffectivein terms of economy and energy conservation.They consume large amounts of electricalenergy, which leads to the further increaseof the demand of main energy production stationsand also underlines the increase of the CO2production, with all the connected environmentalrepercussions. Moreover, the use ofcooling agents - refrigerant gases, which are intheir majority harmful for the environment, rendersimperative the need of immediate applicationof the directives in the direction of energyreduction, their withdrawal of the market andthe use of environmentally friendly ones. Theincrease of the temperature in the urban regionsdue to the urban island effect contributes to theobvious consequences, in the human thermaldiscomfort and in the reduction of the efficiencyof the AC systems, process that leads consequentlyto perpetual overestimated and expensivesolutions. For all of these reasons, the districtcooling technology offers an alternative solution.Not only for the energy, economical andenvironmental benefits, as in the new techniquesthat imports with advanced rational managementof already used forms of energy but alsowith the utilisation of new energy sources, leadingto the challenge of investigating the design -construction and operation of such systems forthe cover of cooling loads in buildings. In thispaper the nature and the characteristics of thedistrict cooling technology, with all the advantagesand the disadvantage as well as with theeconomic evaluation of their application, arepresented. Finally, a great accent is also given inthe applied techniques and the forms of energythat are used.