Heating and cooling equipment is designed to last approximately 15 to 20 years. If your system is older than this, or you have been having any problems, you might want to have its condition assessed. Although replacing HVAC equipment is a major expense, modern systems operate much more efficiently than the older units they replace, which can translate to lower utility bills.
Additionally, older units typically used the HCFC-22 (or R-22) refrigerant. With prices soaring each year due to the R-22 allocations & phase-out in 2019 (ex. 63 million lbs. were available in 2013 vs. 8.8 million lbs. in 2018, 0 lbs in 2020), it is definitely worth switching to an ozone friendly R-410A refrigerant system.
Most HVAC contractors specialize in designing and installing the systems of a few manufacturers, so no one shop is going to carry every major brand. But before you worry about the equipment, it makes sense to find contractors in your area that are knowledgeable and service-oriented.
When picking a contractor, remember that sizing an HVAC unit by matching it to the home and existing duct work requires skill and experience. A poor design typically results in a system that doesn’t deliver a consistent temperature from room to room and costs more to operate.
Another major consideration is the reputation of the company that you will be working with, so be sure to check out their online and association reviews. Your local Better Business Bureau and Trade Associations, such as the Home Builders Association is a great place to start. Google reviews, Facebook reviews, and Angie's List are other great sources.