[rbp]

Oddly enough I am an expert. Not familiar with your climate but there are 2 important things you should consider and without getting into a long technical babble here it is.

First off (if done right) the AC system needs to be sized to maintain a 12 - 15 deg. F difference between the outside and inside and should run for long periods and not cycle on and off. The intent here is not to hang meat in the house but take the edge off and remove the humidity. If the unit is oversized then it will reduce the temperature too fast and leave the humidity high resulting in a damp cave like feeling.

In my opinion, if your house is well constructed and sealed properly then you should be looking at somewhere around 1 TR per 1,000 sqft. If I were you I would buy a 2 circuit coil and 1 - 2 TR unit and 1 - 4 TR unit. Obtain a smarter programmable type controller and you will have 3 stages of cooling, stage 1 is the 2 TR on and the 4 TR off, stage 2 is the 2 TR off and the 4 TR on and the 3rd is both units on for a total of 6TR.

When space temperature is above 74 deg. then on stage 1 cooling. If stage 1 cooling has been running for more than 8 hours and space temperature is above 76 deg. then off stage 1 and on stage 2, if after an additional 4 hours of operation the temperature continues to rise above 78 deg. then on cooling stage 1 and run on stage 3. Continue to run on both units till temperature drops below 77 deg. then off stage 1 and continue operation on stage 2. When temperature drops below 75 deg. then off stage 2 and on stage 1. When temperature drops below 72 deg. then off stage 1.

A humidity sensor should be added such that your sequence would be, when space humidity is above 50% and space temperature is below 72 deg. then on stage 1 cooling. When space humidity is below 45% then off stage 1 cooling.

Our summers are very hot and humid. We get 90% and temperatures of 95 deg. F. in months of July and August. Today will be about mid 80's to 90's and still high humidity. My lake house is well constructed and is 2,500 sqft and I have a 1 TR and a 2 TR unit running the sequence as per above. I have never seen the 2 TR run. The house doesn't need more that the 1 TR. Most people way oversize the AC capacity. Since we do have cold weather in January and February the house is well insulated with R-20 in the walls and R-40 in the ceiling space. Oversizing is the worst thing you can do.