Time filter

Source Type

Le Touquet – Paris-Plage, France

Allel A.B.,Climespace | Merchat M.,Climespace | Senejean B.,Climespace | Wirgentius N.,Helsinki Energy
Euroheat and Power (English Edition)

The main findings of the studies that have been conducted on the refrigeration installations in France, Finland and Sweden and the real-time measurements to assess the overall energy efficiency of chiller systems are discussed. The energy efficiency ratio (EER) of a cold production system is developed for the sources of consumption including chiller, primary pumping system, cooling system used and power consumed by all auxiliary components required for operation. All installations in Finland have been equipped with dry air coolers that are suitable for Nordic climate and the installation in Gothenburg involves an evaluated building that is an office building with 2 electrical chillers cooled with air cooler. The results in the Finland shows that the EER of the water chillers varies between 2.1 and 5.6 and the entire system EER with all auxiliary components varied between 0.7 and 2.4 and in the Gothenburg, the European seasonal energy efficiency ratio (ESEER) of the whole system including auxiliary components is 2.8. Source

De Munck C.,Meteo - France | Pigeon G.,Meteo - France | Masson V.,Meteo - France | Meunier F.,French National Conservatory of Arts and Crafts | And 5 more authors.
International Journal of Climatology

A consequence of urban heat islands in summer is an increase in the use of air conditioning in urbanized areas, which while cooling the insides of buildings, releases waste heat to the atmosphere. A coupled model consisting of a meso-scale meteorological model (MESO-NH) and an urban energy balance model (TEB) has been used to simulate and quantify the potential impacts on street temperature of four air conditioning scenarios at the scale of Paris. The first case consists of simulating the current types of systems in the city and was based on inventories of dry and evaporative cooling towers and free cooling systems with the river Seine. The other three scenarios were chosen to test the impacts of likely trends in air conditioning equipment in the city: one for which all evaporative and free cooling systems were replaced by dry systems, and the other two designed on a future doubling of the overall air conditioning power but with different technologies. The comparison between the scenarios with heat releases in the street and the baseline case without air conditioning showed a systematic increase in the street air temperature, and this increase was greater at nighttime than day time. It is counter-intuitive because the heat releases are higher during the day. This is due to the shallower atmospheric boundary layer during the night. The increase in temperature was 0.5 °C in the situation with current heat releases, 1 °C with current releases converted to only sensible heat, and 2 °C for the future doubling of air conditioning waste heat released to air. These results demonstrated to what extent the use of air conditioning could enhance street air temperatures at the scale of a city like Paris, and the importance of a spatialized approach for a reasoned planning for future deployment of air conditioning in the city. © 2012 Royal Meteorological Society. Source

Tremeac B.,IRSTEA | Bousquet P.,IRSTEA | de Munck C.,Meteo - France | Pigeon G.,Meteo - France | And 5 more authors.
Applied Energy

Projections of future climate suggest increases in extreme temperatures particularly in mid latitudes. In addition, the effect of heat waves, which are becoming a major " summer killer" , is exacerbated in urban areas owing to the heat island effect. Air conditioning (. A/. C) is a key parameter for health problems in case of heat waves since, on one hand, it reduces mortality but, on the other hand, depending on the heat management, it can increase street temperature therefore increasing the air cooling demand. Results of a meso-scale meteorological model (MESO-NH), coupled to an urban energy balance model including a simplified building model (TEB), are used. Simulations based on a realistic spatial cartography of air-cooled chillers and cooling towers in the city of Paris and surroundings have been performed. The simulation period corresponds to the extreme heat wave in Paris: 9-13 August 2003. Five scenarios will be discussed: firstly a baseline without air-conditioning (NO-AC scenario); secondly the actual situation including individual air dry coolers, wet cooling towers and an urban cooling network relying on free-cooling (water-cooled A/. C with the river Seine) (REAL scenario). A third scenario will assume that all the heat is rejected as sensible heat in the atmosphere (DRY AC scenario). Two other scenarios correspond to a prospective where A/. C is doubled. Scenario 4 assumes that all the heat is rejected as sensible heat in the atmosphere (DRY ACx2 scenario). On the opposite, scenario 5 assumes that all the heat is rejected underground or in the river Seine (NOREJ scenario). Results show that A/. C affects the UHI depending on its management. A detailed analysis on selected districts shows that the local temperature variation resulting from heat island is proportional to the sensible heat rejected locally by A/. C, indicating that a clever A/. C management is all the more important to provide comfort and to mitigate heat island. Moreover, the incidence of the sky view factor is also discussed. © 2012 Elsevier Ltd. Source

Discover hidden collaborations