Does the thermostat have a dehumidification feature /function?

If so that is one reason it will over shoot on temperature because of the 3-5 degree dehumidify band (typically). For some less humid markets this band maybe sometimes set to 1 or 2 degrees.

Because an air conditioner is not a dehumidifier they have to give it room to run to allow additional dehumidification.

They limit this feature to 3-5 degree band because often times those that do not understand this operation will think there is a problem with the AC not shutting off when in fact it's because it has entered dehumidification over shoot mode.

The other side of the equation is that the complaint will sometimes be humidity is too high I bought this *air conditioner* to *control* dehumidification in my house the temp is 3-5 degrees lower than set point (or whatever the band is set to) the unit shut off and humidity is too high. The short answer in this scenario is that an air conditioner is not a dehumidifier. (notice I said *feature / function* above -- context for keyboard warriors.)

Another possible scenario is that the unit in question is an inverter AC. Depending on manufacturer and how the machine is controlled (communication t-stat) it may have a dehumidification overshoot function as well. Inverters will run long spans because this is how they are designed to operate. If the inverter AC has a dehumidify feature attached to it via the thermostat could also explain the temperature over shoot. Inverters are *new* (*in terms of HVAC systems for your home* context for keyboard warriors), but are becoming more and more popular everyday because they are the future of HVAC home comfort systems.

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yet another possibility is fresh air cycle.

When you say it doesn't shut off do you mean the AC or the blower?

Because houses are built so snug tight, HVAC systems have a feature /design to bring in fresh air from outside. There's a number of ways in which this can be done. The system's blower is often used if the design is merely a fresh air damper that is usually timed with other controls.

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However, if your AC is overshooting temp, it's probably more likely to be a dehumidify band allowing it to do so.

Dehumidification via an air conditioner is a touchy subject for this board... let's see how many enthusiasts we can get to enter this discussion of "hey, it's not rocket science" this time around? (Buckle Up-- lol)

I service the Katy, Texas area.