Testo 557 vacuum gauge and Appion core removal tools shown I've had a change of heart. Back in the early 2000s, during the big construction boom, I did many system startups on residential units for a large company I worked for. When installers ran the line sets prior to startup, they weren't always very careful […]

When the quiz or the teacher asks what “latent” heat is, there is generally some reference to it being hidden heat, which is what the word “latent” means. We then learn that it is heat energy transferred that results in a change of state rather than a temperature change. Later on, we hear a lot […]

The chart above is from a Carrier heat pump, and it lists some common accessories. I have heard this common pressure switch (last on the list) called a low-pressure switch (because it opens on fall in pressure) and a high-pressure switch (because it's in the liquid line), but RARELY do I hear it called its […]