Following nearly thirty years of service inside public and private sectors within the city, I decided to call it quits and retire from my local job. Having always been hardworking as well as a busybody, it took only a month of not having work to do to become fidgety and begin looking for something new in which to invest my unquenchable higher level of energy. As a technically-minded man, I thought long and hard about anything that I’d enjoy learning more information about that I never quite had the time to master. Then, like a good southern-style heat wave, it occurred to me… HVAC! Happy that I finally found something meaningful that I might be interested in, I signed up for a class at my own local library and dove right into the wonderful world of heating, ventilation, and A/C. In doing so, I discovered a whole lot of information, but none proved to be more valuable than the instruction about how an HVAC system works. In that instructional session, I realized that HVAC systems cool homes simply by blowing warm air–that, in the end, is cooled–back into homes or buildings. Moreover, the air is cooled by being blown over a couple of cold pipes called evaporator coils, which are filled with refrigerant–which is a liquid that changes to gas as it absorbs heat that is in the air. Refrigerant is then pumped from a condenser, in which the refrigerant gives up its heat and changes back to a liquid. A compressor, which is a pump, moves the refrigerant between each of the coils and changes the refrigerant pressure so that refrigerant either condenses or evaporates inside the appropriate coil. It is astonishing the amount of information we have don’t know and have yet to learn!