Abstract: Maintenance of optimum temperature in electrical equipment room of RTU valve chamber in desert areas has been a significant challenge in engineering design of long-distance pipelines. Accordingly, passive cooling techniques are used in design for temperature control in valve chamber. Taking the Iraq project as an example, a passive cooling system is developed based on passive cooling principle. This system includes three components: indoor heat-storage tank and heat exchanger, and outdoor heat exchanger deployed on the roof, which are connected via pipelines into a closed circulation system covering both indoor and outdoor facilities. Value assignment for key design parameters of the system is analyzed. Then, with combination of the solar energy management system (EMS) and supplementation of auxiliary positive cooling equipment, a hybrid cooling system with better serviceability is formed. This innovative cooling system provides an effective solution for temperature control in electrical equipment room in RTU valve chamber. The research results can provide references for pipeline engineering design in Middle East, Africa, Southeast Asia and other areas in deserts or rain forests.