The renewable energy resources appear to be the most effective solution to energy increasing demand. In particular the consumption of energy in greenhouses in Tunisia country has gained an increasing interest. The objective of this work is the heating of the two types of greenhouses (with surface area 100 m(2)) by using the different installations. The heat pump (water/air) system is coupled with a flat plate collector (with surface area 2 m2) and a vertical heat exchanger in order to obtain a comfortable climate in the winter in the greenhouses. The system is subdivides into three parts; (i) the conversion of the solar energy on the thermal energy in the level of the flat plate collector; (ii) increasing this energy at the level of the heat pumps system; (iii) heating the greenhouses by using this abundant and universal source of energy. Here, we present a mathematical description of the heat pump as well as the numerical results of the simulation of the system, such as the coefficient of performance, the outlet temperature in the level of the flat plate collector and in the heat pump system, the temperature and the energy indoor the greenhouse, finally a good results are obtained comparing with others similar results in research area. (C) 2015 Elsevier Ltd. All rights reserved.