Air Conditioning - Carrier A/C Issues

I have a 3.5 ton Carrier a/c unit that was installed in my home when it was built about 3 years ago. My house is about 2100 sq/ft and is in Florida. During the summer I have an extremely hard time getting my house cooler than 80 during the day and I have a diffuser in my front bathroom ceiling that builds up a ton of condensation and drips on the floor. I have had the techsa out numerous times and they are all stumped. I have insulated around the bathroom diffuser boot and it still drips. I noticed yesterday that my air handler is calling for a 1/2 hp motor but the outside unit only has a 1/5 hp motor. I also would like to know what the correct temp split for return and supply air is. Thanks in advance

The h/p for the motor in the air handler has no relevance to the h/p of the motor in the cond unit.

I typically look for a 18-20 deg split.

What size is the supply?


Semper Fi

How did you insulate it? From the back side? I will usually use expanding foam to fill in the opening from the back side. Is the inside of the boot sweating or just the register? Is warm air getting into the bathroom from a vent fan? Warm air leaking in from the outside will hug the ceiling and the mositure in the air will condense when it contacts he colder register.

I insulated it from teh attic around the boot and box. There is an exhaust fan in close proximity to the diffuser, sam eset up as in my master bath but no problems in there. I am not sure what you mean by the size of the supply

Who decided the sizing? I think it's undersized. In S Tx, which has similar weather to FL, we call for 1 ton per 500 sf, so you would need at least 4 tons, and maybe more if you have tall ceilings, large sun exposure on large windows, no shade.

Could be a sizing issue, the charge could be off, could have air leaks. Lots of could be stuff, I was asking what size duct run feeds the bathroom ?

The duct that runs into the bathroom is a smaller one, I can fit my fist into it but not by much. My neighbor has the same size house with the same size unit, of a different brand, and no problems what so ever. In fact his condenser motor died and they replaced it with a 1/3 Hp

As far as air leaks, my home is only 3 years old bu tjust to be safe I checked all the windows and door and everything seems pretty tight

sorry- I should have clarified. What I'm asking is what did you use to insulate the boot? Fiberglass insulation? Styrofoam? Did you mastic over the insulation? Is the inside of the boot on the bathroom side sweating or just the register? Somwhow warm most air is hitting that colder surface. eliminate the warm air, eliminate the problem. You sure ouside air is not coming back into the bath from the vent fan? If you run the vent for 24 hours, will the sweating go away? What size was the old motor on your neighbors unit? An underloaded motor will overheat. You don't want to upsize anymore than 25%.

You keep going back to this motor(in both forums)for some reason. Different units use different motors, is your nieghbors the same as yours?

Was your motor replaced before?

Post M# & S# of both indoor and outdoor equip.

I see your point about different units and different motors, guess I just got excitied thinking I had finally figured out a problem plaguing me for over two years. Model number of insode unit is: FY4ANF042 and outside is: 25HBA342A300

That unit call for a 1/5 h/p cond fan mtr:thumbup: