Lennox and Carrier are two of the oldest HVAC makers around today.
I have been in the HVAC engineering and retrofit business for over twenty years. I have used a lot of different brands. Without regard to price, there are some very nice models out there.
- McQuay International makes some very good units, as does Lennox, York, and Payne.
- I have personal experience with York. They last, but after about five years they begin to have nuisance problems that can only be repaired by a service call.
For the price, I would buy a Trane. I was recently asked to perform a forensic investigation on residential and commercial rooftop units that had been damaged by hail. I found a 45-year old Trane that was still running in spite of the hail damage.
I hope that this helps.