Flowing nitrogen while brazing and pressurizing with nitrogen are great practices. Putting nitrogen in with the refrigerant? Not so much. Nitrogen is a “non-condensable” gas because it cannot be condensed (under normal conditions). However, nitrogen is just one of the non-condensables. First, let's talk about what a non-condensable gas is. Any gas that does […]

We all learned how to read the tonnage off of a model number within a few weeks of beginning in the trade. What you may (or may not) have learned is that just because something has an 036 in the model number, that does NOT mean it actually produces 36,000 BTU/hr. It doesn't reach the […]

  The second law of thermodynamics puts the first law into context and establishes entropy as a concept. We can simply define entropy as a state of disorder that can only increase or remain the same in natural processes. Processes in which entropy remains the same are reversible, but ones that result in an entropy […]