23 September 2011


The need for air conditioning depends not only on the climatic conditions, it also
depends on the size of the building, and the utilisation; an additional problem is architecture,
presently glass is a favorite construction element, and this means that solar gains become
very fast solar loads, which have to be removed by a powerful air conditioning system. We
cannot change architecture, but we can improve the efficiency of air conditioning systems. To
get efficient systems it is necessary to keep temperature lifts required as small as possible,
the heat sink/heat source temperature should be low in the cooling season and high in the
heating season. Using the ground as store as heat sink/heat source, these requirements for
low heat sink temperatures/high heat source temperatures can be achieved. Such a solution
requires higher first cost; however, running cost can be reduced significantly.