Enthalpy is easy. It's just a state function that depends only on the prevailing equilibrium state identified by the system's internal energy, pressure, and volume. It is an extensive quantity. Simple. Like most things, the scientific definition is as clear as mud. In HVAC/R, we use enthalpy measurement to come up with the total heat […]

In HVAC systems, liquid and vapor will exist at the same time and place. We call that condition saturation, or we say that the refrigerant is “at saturation.” Phase changes occur in the evaporator and condenser, so these are spots where liquid and vapor coexist while the system is running. Saturated conditions occur whenever liquid […]

One of the most common parts to fail on a single-phase HVAC system is the run capacitor, so much so that we sometimes refer to junior techs as “capacitor changers.” While capacitors may be easy to diagnose and replace, here are some things many techs may not know: Capacitors Don't “Boost” the Voltage  A capacitor […]