Thanks for being so prompt tigerdunes! OK. I spoke to my hvac company and they did indicate that I would not get much of a rebate ($50 for the performance series- what a joke!) unless I get the infinity ($1000 + $1500 tax credit). Unfortuntely, I don't think I can count on the tax credit so this is a big $1500 deal. My upstairs is about 2300 sq ft with an area open to the main floor (large area about 30X20). The existing system worked ok. During very hot days (90+), I had to close the doors in my bathroom (where there is a 12x12 return) because it is above the garage; closing the door kept it cooler. The other bedrooms also get hot because we get full southern exposure but the temperature seemed ok. Again, if I left the bedroom doors open, the air would escape and if I kept the doors closed, it got really cold(BTW I also have a 20x20 return in the hallway upstairs). The same goes for the heat. I would say that I like to keep my a/c between 73-75 (I have an old honeywell mercury-based thermostat - which I know is not very accurate) and during the winter, I like to keep it between 70-73. This seemed comfortable. You are right - my system has a built-in component for an electronic filter system which is not used. I use regular filtrete filters and replace them every 3 months. For the upstairs unit, I do not use a filter. Instead, I have filters in the 12x12 and 20x20 returns. My a/c guy told me that I could get the Infinity system 80% with a 58CVA furnace + infinity control for $9200. Since I am not sure that I can get the tax credit, it would cost $8200. Is this still worth it? My furnace still has about 8 years to go!? He did tell me that a dual fuel heat pump system would cost about $10,300! Is this what you mean by a heat pump condenser or is this just a specific component within the infinity package? I really want to do the right thing but I do not want to waste money. I pay about $2400/yr for electricity and about $2000 for gas. For such a big place, I am not sure if this is too high or if I can really save that much with an infinity system. What do you think?

With an 8 year-old system, I would replace the compressor. But not for $2500. Get more quotes on replacing the compressor. Once you replace the condenser with a new 13 SEER, using the old coil may be a problem because its smaller than a matching coil. It also depends on how often you use your a/c. Are you in Miami or Chicago, big difference. Good luck.

Best Practice: First, they should prepare the system before brazing by removing the drier inside the condenser & install brazed copper tubing in its place. Then a new properly sized filter drier should be installed on the liquid line exterior of the condenser. If it is a copper coil they can purge the system with dry nitrogen & then flow it at just under 3-psig while they braze the hole & the other changes. Then the system needs to be purged again & double or triple evacuated down to 500 microns, then down to 400 microns & see how well it holds. Then they can weigh in a proper charge according to the size & length of the refrigerant lines. Then after checking the airflow CFM & cleanliness of the coils & blower wheel blades, they can then use superheat, & subcooling if a TXV metering device, to balance the charge to the conditions of the heatload. This is the "Best Practice," doubt they will do the practice to that extent. - udarrell Here is a link that might be useful: Balancing the Refrigerant Charge to normal load conditions

You are right, your condenser does use R22. It must be the last of the R22 condensers Carrier manufactured. You should not sink $2500 in repairing the condenser. My suggestion is to buy a Carrier condenser and coil. No advantage to introduce another manufacturer's equipment unless you can't find a competent Carrier dealer. You should change the line set also. You can't add a 2-speed condenser to a single speed furnace. If the furnace is working well then there is no need to replace it. The furnace is probably over sized for your climate.