I was thinking if this could be something to do with the High Humidity we have here in Indiana and I'm just not use to this.
High humidity, yes, but more importantly a high dew point will significantly affect the rate of AC cooling. A 70 degree dew point at this time of year in Indiana is not uncommon.
So, if the outside air temperature is 80 degrees and the dew point is 70 degrees, when you turn on the AC that air will cool fairly quickly as it passes through the evaporator into the cabin - at about the rate of 1 BTU of thermal energy per 2 degrees of cooling. This rate of cooling will stop abruptly when the air temperature reaches its dew point of 70 degrees. Any cooling of the air from this point on requires the transfer of 970 BTU's (the latent heat of condensation) for every pound of water that is condensed and runs out of the evaporator drain.
So you are correct in thinking that humid (high dew point) days will adversely affect the performance of the AC system.
Using "Recirc" or "Max AC" will help speed up cooling the cabin because you will only be squeezing the moisture from the air just once instead of continuously.
As I write this post, here in the Willamette Vallley in Oregon, the outside temperature is 59 degrees, the dew point is 55 degrees, and the humidity is 86%. So, even though the humidity is high, the dew point is low. Later in the day when the temperature reaches 80 degrees, the dew point will not have changed, so the AC unit will easily cool the cabin quickly.
- John