In this paper a combined energy recovery system is suggested for engine test facilities. System consists of two semi loops which are being active according to the temperature of the air feeded to the test cell. Winter and summer semi loops are introduced with the system requirements and equipments. Working principle of both semi-loops and components with the selection critera are explained. Also cost and benefit analysis is given in detail.It is evident that hot exhaust gases of the combustion processes is the main source that a large amount of energy wastes through it. Researchers confirm that more than 30% - 40% of fuel energy in the internal combustion engines wastes from the exhaust and just 12% -25% of the fuel energy converts to useful work. In the other hand, statistics show that producing numbers of the internal combustion engines growth very fast and the concern of decreasing the fossil fuels will be appeared. So, researchers are motivated to recover the heat from the waste sources in engines by using the applicable ways. Thermoelectric generators (TEG), Organic Rankine Cycle (ORC), Six stroke engines, Turbocharging, Exhaust gas recirculation (EGR) and exhaust heat exchangers (HEXs) are proposed technologies to recover waste heat in engines .Although there are many studies revealing analysis of the systems for energy recovery from exhaust gas, a few of them are related with the heat recovery during engine testing cycles. The objective of this paper is to suggest a proper heat recovery system for engine test facilities.