Air conditioning was about humidity control from the very start. Willis Carrier's very first air conditioning system was all about controlling the humidity with the side effect that it also could reduce the sensible temperature. Theaters caught on that this newfangled contraption could lead to big summer numbers when they installed it to keep patrons […]

I had an old-timer tell me that you can never connect two transformers together because they will “fight one another.” If you are anything like me (and heaven help you if you are), a cartoon in your head starts playing whenever someone says something like that. In this case, I imagine two transformers with boxing […]

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 […]