Its All Greek to Me!

Years ago a proper education included the study of Greek. Why? Because so much of our modern language and western culture is rooted in Greek culture. As education has moved away from studying classics and Greek, we have retained many symbols and phrases without really understanding them. Even in HVACR, we use Greek symbols on a regular basis. Ever hear someone refer to taking a “Delta T” measurement? This simply means to measure the temperature difference, or change in temperature. Delta comes from the uppercase of the fourth letter of the Greek alphabet, which looks something like a triangle, Δ. In many math and science fields, Δ is used as shorthand for change, or difference. One way to think about this is to look at the form of the letter Δ. It changes in width from the top to the bottom. An easy way to remember it is simply that Delta starts with “D” and Difference starts with “D.” So Delta T simply means temperature difference. It just sounds so much more educated to be checking out a system’s Δ T. Two more commonly used terms which come from Greek are: zeotrope and azeotrope. Zeo means to boil, Tropos means to turn; thus, a refrigerant which is zeotropic turns, or changes as it boils. “A” used as a prefix means “not.” For example, amoral means not moral. Similarly, azeotrope means a refrigerant that does NOT change when it boils. If you understand where the terms come from, they seem a little less confusing.