Method and apparatus for controlling an air conditioning unit with multi-speed fan and economizer

Claim 3

The method as set forth in claim 1 and further including the step of energizing the air handling means at an increased volume flow rate whenever the signal indicative of the difference between the desired temperature for the enclosure and the temperatures sensed exceeds a predetermined level.

Claim 4

The method as set forth in claim 1 wherein the step of energizing the air handling means at a reduced volume occurs when the air conditioning unit is operated to remove heat energy from the enclosure air.

Claim 5

The method as set forth in claim 3 wherein when the step of positioning places the dampers in a fully open position the air handling means is energized at the increased volume flow rate.

Claim 6

The method as set forth in claim 1 wherein the air conditioning unit is capable of supplying heating as well as cooling to the enclosure and further comprising the step of: energizing the air handling means at the increased volume flow rate whenever a heating need is sensed.

Claim 9

The method as set forth in claim 6 wherein the fan motor is energized at low speed during those time periods the unit may condition air to be supplied to the enclosure.

Claim 10

The method as set forth in claim 7 wherein the unit includes two refrigeration circuits each having a compressor and wherein the step of generating a signal indicative of the difference between the desired temperature for the enclosure and the temperature sensed when the unit is in the cooling mode of operation comprises the steps of: generating a first signal upon a first difference being determined; generating a second signal upon a second difference being determined, said second signal acting to energize the compressor of the first refrigeration circuit; generating a third signal upon a third difference being determined, said third signal acting to energize the compressor of the second refrigeration circuit; and generating a fourth signal upon a fourth difference being determined.

Claim 11

The method as set forth in claim 8 wherein when the damper means is positioned to allow ambient air to enter the unit the fan motor is operated at high speed in response to any of the second signal, the third signal or the fourth signal.

Claim 12

The method as set forth in claim 8 wherein when the damper means is positioned to prevent ambient air to enter the unit the fan motor is operated at low speed in response to the second signal and the third signal and in high speed in response to the fourth signal.

Claim 13

Air conditioning apparatus for supplying conditioned air to an enclosure, said air conditioning apparatus including a multi-speed motor for powering the indoor fan, a refrigeration circuit and an economizer including damper means which comprises: a thermostat located within the enclosure to be conditioned for generating a signal indicative of the temperature differential between the desired temperature and the actual temperature of the enclosure means for sensing the temperature of ambient air; economizer control means for positioning the damper means of the economizer as a function of the enclosure temperature and ambient air temperature; circuit means for energizing the fan motor when the refrigeration circuit of the air conditioning unit is energized to maintain the enclosure at a predetermined temperature level means for energizing the fan motor at high speed when economizer control means opens the dampers to allow ambient air into the unit; and means for overriding to energize the fan motor at high speed whenever the temperature level of the enclosure varies a predetermined amount from the desired temperature.

Claim 14

Air conditioning apparatus for supplying conditioned air to an enclosure, said air conditioning apparatus including a multi-speed motor for powering the indoor fan, a refrigeration circuit and an economizer including damper means which comprises: a thermostat located within the enclosure to be conditioned for generating a signal indicative of the temperature differential between the desired temperature and the actual temperature of the enclosure means for sensing the temperature of ambient air; economizer control means for positioning the damper means of the economizer as a function of the enclosure temperature and ambient air temperature; circuit means for energizing the fan motor when the refrigeration circuit of the air conditioning unit is energized to maintain the enclosure at a predetermined temperature level means for energizing the fan motor at high speed when economizer control means opens the dampers to allow ambient air into the unit; and means for overriding to energize the fan motor at high speed whenever the temperature level of the enclosure varies a predetermined amount from the desired temperature.

Claim 15

The apparatus as set forth in claim 10 and further including: means to prevent the fan motor from being energized at high speed when the economizer control means closes the dampers preventing ambient air from entering the unit except for when said means for overriding is energized.

Claim 16

The apparatus as set forth in claim 10 wherein the means to prevent includes normally closed power exhaust relay contacts connected between a power source and the high speed fan relay, and an enthalpy control connected to energize the power exhaust relay, such that energization of the power exhaust relay through the enthalpy control caused by high ambient temperatures opens the power exhaust relay contacts preventing the fan motor from being energized at high speed regardless of the temperature of the enclosure as long as the temperature does not exceed the temperature differential to override with the means for overriding.