Selecting Outside Air on a vehicle is a Catch22. Recirculate operation varies by manufacturer but it is generally a blend of Outside Air and Recirculated cabin air. In the Summer, outside air brings in warmer and in most states more moist air. The extra heat and/or moisture is a heat load that has to be removed by the A.C. which forces it to work harder. In the the Winter, you need Outside Air that is warmed by passing through the heater core to remove the excess moisture that builds up in the cabin from your breath. That glass is cold enough that the moisture steams up / freezes onto the windows. A.C. speeds up that dehumidification. Selecting Defrost on most cars switches to Outside Air and turns on the air conditioner regardless of outside temperature so in cold climates you have to add extra heat in with the heater core to compensate for the A.C. cooling.