Do I need a new AC Unit?

Hello /r/HVAC. First time poster.

I'm in one of the classic "My AC isn't really cooling my house as much as I would like it to" scenarios.

Last summer, my AC unit seemed to struggle cooling my home. It is a Rudd unit that was installed when the home was built in 2003. I'm from Madison, WI and it can get pretty humid here.

This summer, the AC unit seems to be functioning poorly. We like our home to be around 72 degrees. For the last month or so, the peak heat of the day is 85, and the AC unit struggles to keep the house below 74 despite running all day everyday for the last month. Today, it's 93, and the house is around 79 degrees.

What I've done so far:

A few weeks ago we had someone out to check out the air conditioner. The charged $95 to show up. $200 to do a chemical clean of the outdoor unit. $200 for a "diagnostic check" of the unit (visually inspect wires, check to see what the difference in temperature was between the intake air and the return air was) and $200 to refill the unit with 12oz of Freon. When they initially did the diagnostic test, there was a 9 degree difference between the intake air and the return air. After they were done, there was a 16 degree difference between the intake air and the return air. This seems low to me as everything I've read says that the difference should be around 20.

Some possible things that could be creating the problem:

• The AC unit is a Rudd, and it's 13 years old.
• We had a Radon system installed during the winter. Perhaps there's some kind of sealing issues that means we are losing conditioned air. I think this scenario is unlikely because we have any CO issues, and we didn't see an increase in our heating bills in the winter.
• Perhaps we are expecting too much of our AC. 72 is unrealistic during the heat of the summer.

What are your thoughts? If you think we should replace the system, any particular brands you recommend? Any I should stay away from? Also, anyone in the Madison, WI area do installs :).

Thanks in advance for any information provided.

submitted by /u/ericgcollyer
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