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? […]

Friction rate is a value located on a ductulator. We use it during the design phase of a duct system to predict the operating static pressure of a duct system. The challenge with friction rate is that it is often misapplied by folks using a rule of thumb (ROT). In order to apply friction rate properly, […]

This is the first of a three-part series of articles that will dive deep into advanced psychrometrics. The source material for each of these articles may be found in ACCA Manual P Sections 3, 4, and 5. This article is based on information found in Section 3.  Psychrometrics is the study of the physical and […]