Hi, my ac keeps getting louder every year. Is there any way to quit down the compressor? It has a knocking sound.

Also I was thinking about getting a new unit. And I was told I could not put a new 13 seer unit on my old coil is this true?

Have you had a licensed HVAC person check out your compressor as the knocking sound getting louder is not a good sign and can be a number of things. Better have it looked at before is seizes up totally and you are left with no a/c come summer when it gets really hot and the unit will be under a lot of stress.

If you are getting a new unit with 410 instead of r22 then you will need a new coil. If you are getting a r-22 unit you don't have to change the coil as long as you put a TXV valve on it. As far as the loud compressor. You can try picking up the unit and dropping it, or anything to jar the compressor. This may reseat the valves and quite it down for a little longer.

What is the advantage or disavantage of 410 over 22?

I was given a price for both types of units. But was told the coil needs changed for both.

I would get a 410a unit if you have the cash to do so. It will cost a bit more as I am sure you have seen with your bids. But they tend to put out colder air and the price of r-22 is going to start climbing.

What was the price difference between your bids?

Not much you can do to quite the compressor, its just wearing out. You can put in a new 13 seer condenser and still use your existing evap coil, as long as the oriface in the evap coil is sized correctly. If you are looking at updating, I would go with the 410 system. R 22 is going the way of r 12. It will soon be hard to find, and very expensive to purchase if you do find it. We still install units with r 22, as of now. But it won't be long before you can't even purchase these units. 410 is the near future, so I would suggest going with it.

Personal thought. I wish I had bought a few thousand pounds of r22 about two years ago. It would sure make for a nice retirment.

I agree, it is $195 a jug. I do still have 100lbs of r-12 left