I'm going to say you are overlooking, omitting or mis-stating some fact(s). If it cool's,it will dehumify. If it dehumidify's there will be water in the pan. It's simply one of the laws of refrigeration. I would normally say return air was leaking but the pan would have lots of water in it in that event.

what is your thermostat temp setting?...what are your typical runtimes?...how many cycles/hr?...when was the last time your AC system had a PM by a qualified pro?...how old is your AC system?..what is your average supply temp and average return air temp?..post back.

IMO

Thank you both so much for responding.

First, I agree that this seems to denounce the laws of refrigeration, hence my frustration. So when I say there is not water in the pan, I was referring to the overflow pan. There is water in the pan inside the unit under the coils. As far as temperature, when I say cooling is working, I am basing that on the thermostat reflecting a temp where it is programmed, and that is in synch with another digital humidity and temperature meter I bought. I have placed it on top of the thermostat box, and then in various places around the upstairs to see how much the temp and humidity actually varies.

We keep the temp at 76/77, and the thermostat reflect that temp, as does the extra humidity/temp monitor. But the humidity says 60%.

I did not have the humidity/temp gauge before this issue started last summer, so I really don't know what the humidity level was before. But it clearly does not feel the same as it did before.

I checked run time the other day - it was ~7 minutes I think on the high speed; haven't checked it (but can) on the low speed.

I am not sure the age of the system b/c we bought the house 14 yrs ago, so at least that old.

I think I answered all...again, thank you so much

bring your thermostat setting down to 74...run for 12-24 hrs and then check humidity level...check runtimes... 7 minutes is not long enough...what is your location, what is high outside temp during the day?...post back tomorrow..

IMO

There should not be any water in the overflow pan unless something is wrong with the primary drain. If that (the primary) is making water, it is a good sign.

Seven-minute run times in hot weather is too short, generally. How long does it stay off before coming on again? Confirm that a vent is not blowing on the thermostat.

If you tell me that it is seven minutes on/seven minutes off set to 76* with an outside temp of 97*, I will say it is oversized.

"Also have checked the drain lines - no clogs, and in fact, the drain pan has been dry." " So when I say there is not water in the pan, I was referring to the overflow pan. There is water in the pan inside the unit under the coils."

Did I mention , you are overlooking, omitting or mis-stating some fact(s). ??? And there she is plain and simple. With that straightened out I'll stick by my initial knee jerk,leaking return. Useing a sensitive and accurate thermometer,record air temp at intake GRILL and then record temp immediatly before air enters blower. If you find more than 1 deg differential,investigate for return leak and/or poorly insulated return. You will get advice about load calculations and such more suited to trained pros but do the simple things that better fit your wheelhouse before getting that deep. There's a recent trend of pulling all the stops regardless what the complaint is. Here's something to consider. It is plenty hot and humid in Houston Tx where many systems are intentionly oversized. It's hard to find people complaining because their ac is too large. Until you reach about 30% oversized,the biggest difference is increased operating cost. If your place call's for 3.5 tons cooling you will not complain about being uncomfortable with a 4.5. If it were so simple anyone could tell you the problem, techs wouldn't have to come out in person to figure these things out.

what location?

in my hot humid climate return air leakage adds

to higher indoor relative humidity.

the average house has 30% duct/return loss.

real pita to seal, but worth every drop of sweat.

best of luck