Tech Tips

In order to wrap my head around diagnostic issues, it helps me engage in thought experiments where I think of more extreme examples of an issue or situation or consider the ideal to find the “edges” of a concept. Once I find the extreme edges, I can begin to sort down to a more exact […]

We’ve all probably been in this situation before (maybe in both people’s shoes at different points of our careers): A technician is on the job with their apprentice. The technician tells the apprentice where the probes go on the service ports and exactly what the superheat and subcooling are.  The apprentice’s eyes glaze over, and […]

Even if you're not a market refrigeration tech, we all know that the primary function of refrigeration is to keep food cool. Easy, right? Even though food storage sounds pretty simple, there are a lot of things we should keep in mind when we think about food safety and quality. There’s a lot more to […]

The summer is a season of opportunity for HVAC technicians, and by opportunity, I mean a super high volume of service calls with a greater chance of callbacks.  We’re based in Florida, so our techs have to deal with the combination of blistering heat and higher humidity. That combo can cause all sorts of problems: […]

In a series circuit (loads connected in a row end to end), it's easy to calculate total circuit resistance because you simply add up all the resistances to get the total. In a parallel circuit, the voltage is the same across all the loads; the amperage is simply added up, but the resistance is a […]

You know the feeling that sets in your chest before you finish reading that nine-word text: Hey you got a minute? I need some help.  No details. No system description. Just that, from someone who doesn’t send that text unless they’ve already exhausted everything else. Let’s talk about that feeling. What’s Actually Happening to You […]

The amount of pressure you're under depends on where you live. I live in Florida, so I'm very close to sea level. Therefore, the weight of the atmosphere is exerting exactly 14.7 pounds per square inch (PSIA) of pressure on every surface in every direction. There is no such thing as negative pressure—only pressure lower […]

When I was a green tech, I was really big into showing up all the other techs by doing THE BEST cleaning I possibly could. One of my favorite things to do was to clean the condenser until it was SPOTLESS inside and out. The only issue was that I really liked using that brown […]

Does setting a thermostat too low cause an air conditioning system set in cool mode to freeze? The answer is no, at least not directly. However, low evaporator load (low return temperature or low airflow) and low outdoor ambient temperature can lead to evaporator coil freezing. Low indoor setpoint can lead to low return air […]