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 […]

Both wet-bulb temperature and air enthalpy are extremely useful to understand when calculating actual system capacity and human comfort. Dry-bulb temperature is a reading of the average molecular velocity of dry air. However, it does not account for the actual heat content of the air or the evaporative cooling effect of the air. When air […]

Heat is a byproduct of mechanical energy that presents itself as a temperature increase. French physicist James Prescott Joule aimed to equate heat to mechanical energy. Early experiments used paddle-like structures to stir water within a container and raise its temperature. The paddles would move and agitate the water whenever a mass on a pulley […]