Can someone confirm the both units are 2.5 tons? Also what is the max blower motor speed for the air handler. I can't read the dataplate on the motor.
I may be replacing this unit. I'm looking at a Payne PH13NR030 condenser and a Payne PF1MNC030. These are 2.5 ton units.
The A/C guy I'm working with says the Payne unit will replace the Lennox with no problem. The Lennox unit has what appears to be a double inverted A coil. The Payne unit has a slant coil and appears to have much less coil surface area.
Both are rated at 2.5 tons. Maximum blower speed relates to the static pressure of your duct work. Could be a maximum of 1400cfm to as little as 765cfm. I do not know much about Payne's newer equipment. I would strongly suggest that you inquire about a "Manual J" or any other ACCA approved heat load calculations to make sure that the "A/C guy" you are working with is properly sizing the equipment for your home and ductwork.
As a Lennox Technician I feel basic repairs and maintenance can be performed by the homeowner. But I highly suggest that periodic maintenance should be made by a certified licensed technician. You should contact your local Lennox technician for any repairs or issues that are outside your comfort zone. Property damage, personal injury, and death can occur from improperly repaired or maintained systems. Replacing a part doesn't always resolve the issue that caused the part to fail!