The most common method to defrost appropriately in refrigeration involves both time for initiation and a combination of time and temperature for defrost termination (ending defrost). But why can't we just use temperature or time alone? (You may wonder.) Imagine a common freezer with a designed box temperature of -10°F and a coil temperature of […]

In commercial HVAC, you will find several different types of multi-stage evaporator coils: intertwined (shown above), horizontal face split (one coil on top of another), and vertical (side by side). When staging a horizontal evaporator, pay attention to ensure that stage #1 is on the bottom and stage #2 is on the top. If stage […]

In HVAC and electrical school, one of the first things you learn about electricity is Ohm's law: Volts (V) = Amps (I) x Ohms (R) Pretty simple, right? Watt's law is just as easy: Watts (P) = Volts (E) x Amps (I) With this newfound knowledge, the student walks confidently into the real world with […]