Changes of summer air temperature during the last 28 years in Athens

The increase of living standards in buildings andhigh summer maximum air-temperature valuesduring the last years have increased the installationof A/C in buildings. Analysis of the summerambient temperatures is thus necessary toinvestigate the important impact on energy consumption.Ambient temperature data from theNational Observatory of Athens station for theperiod 1977 - 2004 are presented. The numberof hours with air temperature above 30C, aswell as the degree hour values (DH) in base of30C are statistically analysed in order to evaluatepassive, hybrid and conventional coolingsystems and techniques.The general conclusion of this study is thatduring the last 15 years a dramatic increase ofthe number of hours with high air temperaturesin combination with an increasing persistence isobserved. However, this corresponds to the risingpart of a cyclic change and therefore, a significantincreasing tendency can not be established.