Air conditioning apparatus

Claim 1

Air conditioning apparatus for regulating the temperature of air circulating within an enclosure comprising: A. a structure serving as a housing; B. heat exchange means disposed in said housing through which a heat exchange medium is passed; C. a fan for supplying a quantity of air flow in heat transfer relation with the heat exchange medium passing through said heat exchange means, a constant speed electric motor operatively connected to said fan to rotate said fan at a constant speed; D. means defining an outlet from said housing through which the treated air is discharged into the enclosure, said heat exchange means being disposed in the housing between the outlet and the fan; E. means for sensing the temperature of the air in the enclosure and generating a variable control signal, the magnitude thereof being related to the sensed temperature; and F. means for receiving the variable control signal and operating in response to said signal to vary the discharge area of said outlet means, said means serving to increase the discharge area when conditions in the enclosure as indicated by the variable control signal require a greater quantity of treated air and serving to decrease the discharge area when conditions in the enclosure as indicated by the variable control signal require a lesser quantity of treated air, static pressure in the housing increasing as the discharge area is decreased and decreasing as the discharge area is increased so that the velocity of the treated air discharged from said outlet is increased as the quantity of air discharged is decreased and is decreased as the quantity of air discharged from said outlet is increased to maintain a substantially constant discharge momentum; said means for receiving said variable control signal including an operational amplifier, and first and second diodes, said first diode permitting only passage of a positive polarity voltage and said second diode permitting only passage of a negative polarity voltage.