DISCLAIMER: HVAC School is NOT an official OSHA safety training resource! Although we provide safety tips in good faith, our website is not a substitute for safety training from an authorized OSHA training source. Many things may deter people from working in the HVAC industry. Perhaps surprisingly, exposure to heights could be the deal-breaker. (Not […]

You may have noticed that 3/8″ liquid lines are generally the norm in equipment 5 tons and under. We went to a job where the system had a 1/2″ liquid line, and it got me thinking about the ramifications of going larger or smaller on the liquid line. Liquid Line Basics The liquid line should […]

In residential, most techs and installers size the suction (vapor) and liquid lines to the stubs on the equipment. In larger built-up systems, sizing the piping is rarely the responsibility of the technician. But what happens if we show up to a job where the lines cannot be (reasonably) replaced because the size is different? […]

Dick Wirz, author of Commercial Refrigeration for Air Conditioning Technicians, talks about making the switch from A/C to refrigeration. Dick Wirz is an advocate for using rules of thumb, which is a controversial position. However, rules of thumb are an excellent way for A/C techs to dip their toes into the refrigeration world. Rules of […]