In the last years a constant growth of energy consumption for air conditioning and cooling systems has been observed. Technologies, which use solar heat for cold production, are gaining more and more in importance. In the passive-house office building ENERGYbase/Vienna a „Solar driven Desiccant Evaporative Cooling"-system (SDEC) is in charge of the air conditioning. It is driven with solar energy, which is used for the heating and cooling of the air. Due to higher material application in a SDEC system compared to an air-conditioning reference system, the performance of the SDEC system during the whole life cycle (production, use and disposal phase) has been analysed. Even though energy efficiency have a lucrative and attractive purpose during the use phase, resource efficiency must not be neglected in product material decisions. Therefore innovative technologies should be questioned if newly applied products with energy intensive and seldom materials are energy efficient all over the life cycle. Global energy requirement and resource depletion for production (grey energy) and deposition of materials have to be taken into account when assessing innovative products.