The purpose of this work is to study the possibility of chiller condenser heat recovery in a given site. Two possibilities to perform savings are studied: the cascade system and the single condenser system. The performances to be reached by a cascade system in order to be competitive compared to classical heating systems, are attainable in real situations. Such a system can supply all the studied site in heat during all the summer period but only partially during the winter period. Its installation is considered too hazardous in the studied site, even if it is a competitive way to make savings and to reduce CO2 emission. The single condenser system gives better performances and can be installed in the studied site by modifying some heat users appropriately chosen.