The use of solar systems combined with air conditioning units is a difficult task, though it can be, under specific conditions, effective.

In air-water systems the solar thermal yield can be used to pre heat the water for the hot water circuit. In this case it is recommended to use high temperature solar systems, like the vacuum pipe collectors.

Applications of this scheme have been carried out, mainly in smaller buildings, in several countries. Still, as the thermal capacities of air conditioning systems are by and large much higher than those of solar systems, the main field of applications lies in the utilisation of diurnal or inter-seasonal storage vessels, combined with heat pumps.

In this case the stored heat is been used by the heat pump to reduce the cooling load that has to be provided by the A/C unit. Successful implementations of such systems have proven that the peak cooling loads can be reduced by up to 30%, as in the case of the Nice airport. This reduction is significant, as it allows a reduction of the central A/C unit's installed power, enabling therefore savings both in terms of initial and running cost.