| Summary: | The report presents a study of how the feasibility of using free-cooling in a supermarket changes when more efficient display-cases are being used, Free-eooling means the use of natural low temperatures , i .e, cooling with free heat sinks in the nature like cold ambient air. The study has been perfonned for a typical siapermarket layout with normal, better and high efficiency display-cases at two locations in Sweden with different climates, Gothenburg and Luleå. A supermarket normally has a net heat surpius if the condensing heat from the refrigeration machinery is taken into account. A typical supermarket, at the same time, has a large internal heating demand during the year duc to the cooling effect of the display-cases. Better display-cases means a reduction in the internal heating demand and a small internal cooling demand is noticed, For a supermarket with high efficient display-cases, there is in general a internal cooling demand during most of the year. There is a large need of energy to satis the internal heating and cooling demands. But this energy demand can be substantially reduced, mostly through different kinds of energy recovery. The report discusses the possibility to use free-cooling to handle some of the cooling requirements of the supply air in the air-conditioning system. In a typical supermarket there is normally no internal cooling demand and free cooling could instead be used to, indirectly or directly, cool the display-cases. But this requires much lower temperatures (-8 °C to 0 °C) of the free-cooling source, which limits the use of free-cooling. The potential increases when more efficient display-cases are used in a supermarket. This is duc to the store now has an internal cooling demand, The internal excess heat in the supermarket, however, is easier to cool by free-cooling because the cooling temperatures do not need to be as low as for the display-cases. Normally supply air, from the air-conditioning system, with a temperature ( l 5 °C) slightly lower than the temperature in the ...
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