which the dual reset controller is employed to control the flow of hot air cold air or a mixture thereof into a controlled space once again the same reference numerals in fig1 and 2 are used where applicable in order to distinguish duplicated components h and c suffixes have been added to identify those used for hot air and cold air controls respectively as shown the temperature controlled space 10 receives conditioned air through duct 11 and grille 12 the conditioned air in duct 11 may be hot air delivered by hot air duct 11h cold air delivered by cold air duct 11c or a mixture thereof a normally closed damper 13h in the hot air duct is biased toward closed position by spring 14h acting through a linkage 15h and opened by a pneumatic actuator 16h opposing the spring 14h the spring is selected to maintain the damper 13h closed until the pressure in the actuator 16h exceeds a predetermined value such as 7 psi and to permit full opening of the damper at another predetermined pressure such as 13 psi a normally open damper 13 39 c in the cold air duct is biased toward full open position by spring 14c acting through a linkage 15c and closed by a pneumatic actuator 16c opposing the spring 14c the spring is selected to maintain the damper 13c fully open until the pressure in actuator 16c exceeds a predetermined value such as 3 psi and to permit full closure of the damper at another predetermined pressure such as 9 psi it will be seen that the control range of pressure is then 3 13 psi which is common only cold.