Air Conditioning - A/C problems...lots of causes?

I came home to a warm house and saw that my lines were completely frozen and a big block of ice where the large line meets the outside unit.

Thawed everything out only to find that my drainage pipe was clogged...so I unclogged it.

Went outside to the valve where the lines meet the outside unit and noticed that the top bolt was loose. I'm guessing that might have caused a freon leak.

Called a tech and he verified that it was low on freon and charged me back up. Things are up and running and the air is a little cooler, but not as cool as I think it should be.

I reexamined the outside unit and noticed where the smaller of the two lines enter/exit the coil, a small section of the fins are white and brittle where a lot of it has broken off. Probably about 6 square inches. Is this a bad thing and could this contribute to my system not cooling efficiently? The rest of the coil looks fine and has been cleaned recently.

Thanks!

white and brittle sounds like your coil might be going bad and not letting air flow throught it . as good as it use too

This sounds like either a neighborhood male dog has visited your unit. The other possibility is when the unit was cleaned & if a chemical coil cleaner was used, it was not completly rinsed off. Some of the newer alkaline coil cleaners can be really rough on aluminum if not completely rinsed off. A small area like that should not make a major difference in performance.

Your guy that recharged the unit may not have gotten the charge level correct the last time I saw a publication that mentioned a survey on residenatial units having proper charge level, it stated that 70% were charged to the incorrect level this of course causes poor cooling/long term equipment damage and excessive energy use, have the tech back out and make sure he charges by superheat and subcooling method to get the charge level correct.