Johnson Controls P66AAB-1 Fan Speed Control 190-250 PSI 5'

The Johnson Controls P66AAB-1 Fan Speed Control is a pressure-activated device used to control the airflow of HVAC systems. This control is used for wall hanging and has manual dial but this does not function in a similar way as the P266BHA-2K type. Unlike most units where the user is forced to enter the speed, the P66AAB-1 utilizes a 5-foot-long steel sensor tube to determine the refrigerant pressure within the system. The pressure range is between 190 and 250 PSI. Whenever pressure rises or more cooling is required, the P66AAB-1 is able to adjust the fan speed on its own. When pressure decreases (which implies low cooling demand), the speed of the fan decreases as well.