This paper describes work completed on behalf of the Commission of the European Community to develop a control device which may be used within air type solar collectors to regulate airflow. A prototype comprising of a temperature sensor/actuator, control cable and air damper was designed and tested within a simulated solar wall system. The operating characteristics of the complete system were optimised to obtain maximum energy recovery by adjusting the inlet and outlet configurations of the solar wall. In addition, a number of commercially available sensor actuators were tested and rated in order to obtain the best time/temperature response and actuator force development characteristics.