Do I need AC charge?

[paulmars]

What else could be wrong?

10-12° difference between vents and return. This season and last. Never tested previously.

Last season large copper pipe at condenser was 64°, this season it's 76°. Both tested several times on different days. Never tested previously.

yes unit was on cool and fans were spinning when tested. Always waited at least 5 minutes after unit switched on to read temperatures.

This unit was installed in 2001, but is rarely used. It's never been charged since installation. Yes, I live in west central florida, but I use my heater more then the cool. It still cools me fine, but it does take slightly longer to cool the house.

Im affected more by humidity then heat. When Im uncomfortable, I set it to 2 degrees cooler then the ambient at that specific time. I might turn it off before the cycle completes or after it completes. Sometimes I let it cycle on and off a few times. Unless it's very hot and sunny outside, one cycle is enough to make me feel fine for a few hours.

When this unit fails, if i can't fix it myself, I might have to resort to window units.

I been reading a lot of service maintenance info online. Some of the things Ive checked:
no air leaks in duck-work.
vents and return are not blocked.
no fluid leaks.
I washed the condenser coils with foaming coil cleaner.
mtr spins free.
inspected electrical connections.
Duel cap read 38/5ufd and should be 45/5, so i replaced it.
I cant clean the evaporator coils with foam, but the top side looks fine.

Id like to do what i can to make this unit last.

tks

 

[user 4883]

check the relay contacts and air filter.
other than that, yes, it sounds like you could benefit from a freon level check.
this will require gauges and knowledge on how to use them.

 

[Sparky617]

No frost on the refrigerant lines? If it hasn't been serviced since 2001 there is a good chance the refrigerant is low. When it gets low enough you'll get frost on the lines and on the indoor coil. Is this an all in one unit? We have a lot of "gas packs" installed in my area where there isn't an inside unit, The unit is installed next to the house and the ducts go from the unit into the crawlspace so the compressor, coil, and air handler are all in one box. These usually have a gas furnace in the unit as well, hence the name gas pack.

 

[user 4883]

No frost on the refrigerant lines? If it hasn't been serviced since 2001 there is a good chance the refrigerant is low. When it gets low enough you'll get frost on the lines and on the indoor coil. Is this an all in one unit? We have a lot of "gas packs" installed in my area where there isn't an inside unit, The unit is installed next to the house and the ducts go from the unit into the crawlspace so the compressor, coil, and air handler are all in one box. These usually have a gas furnace in the unit as well, hence the name gas pack.

"Service" usually does not involve adding more freon. A properly charged unit with no leaks will not require more freon for the life of the unit.

 

[Sparky617]

"Service" usually does not involve adding more freon. A properly charged unit with no leaks will not require more freon for the life of the unit.

It is pretty unlikely a 20 year old unit hasn't developed a slow leak. That is pushing end of life pretty hard. I've gotten 22 years out of mine and I'm planning on replacing them this fall.