There is certainly a lot of change taking place in HVACR! New refrigerants to replace old standards and even newer refrigerants to replace the new refrigerants. Variable capacity compressors, communicating control systems, and communicating thermostats that look like an I-pad. It is tempting to say, no thanks, I will just stick with my R-22 units with single speed compressors operated by contactors that are controlled by mercury bulb thermostats. And yes, many of those are still around. However, if you choose to specialize in only retro technology, you are choosing to become obsolete. Technology changes whether or not we want it to. If your job is to install and service air conditioning equipment, you need to be familiar with what is current, or eventually you will be out of a job. I remember many years ago a technician in a parts house declaring that he simply refused to work on heat pumps. He basically was saying it was too much bother to learn about them, so he would just keep working on natural draft gas furnaces and air conditioners. He would not be doing much today because most the systems in this area are heat pumps and the rest are induced draft furnaces. What he was comfortable with just does not exist anymore. As technology changes, we have to adapt. Studying is just part of a technician’s job. I read about what is going on in the HVACR field almost every day. There are so many resources now. My favorite is the RSES Journal, but I also really like the Air Conditioning Heating and Refrigeration News. I will even pick up a book on occasion. Yes, I realize that reading printed material is somewhat old school, but both publications also have on-line articles. And there are always blogs. If you prefer face to face, find a local RSES chapter. The point is we all have to be students to stay current. Otherwise, we become as obsolete as mercury bulb thermostats and natural draft furnaces.