Tech Tips

We've been getting many questions on micron gauges that are ”going haywire” or reading in the micron range, even at atmospheric pressure. First, micron gauges measure absolute pressure, so you can’t ”zero” them out. They use tiny, very sensitive sensors that are calibrated to air, not refrigerant, so anytime refrigerant gets into the gauge, it's […]

On occasion, you will either find a furnace or be tasked with installing a furnace where the coil overlaps the edge of the furnace because the coil is wider. In the case of a Carrier CNPVP coil, you need to ensure that you align the coil according to the manufacturer's specs, or you risk cutting […]

  Illustration Courtesy of Emerson CO2 is a pretty nice refrigerant. It has zero ODP (ozone depletion potential) and a GWP (global warming potential) of 1. CO2  has been used as a refrigerant almost from the very beginning of refrigerants, and it's been making a big comeback in market refrigeration (especially in colder climates). CO2 […]

This tip was written by HVAC Applications and Technical Specialist Dakota Brown. Thanks, Dakota! As a technician, it was always the same old story: Are you done yet? There was always pressure from the office—either from the dispatcher, service manager, or project manager—to get the job done and get it done quickly. When I became […]

This tip comes from market refrigeration and controls technician Kevin Compass. Thanks, Kevin! A little tip when changing liquid cores: If you start pumping them down, begin bypassing discharge gas into the shell to warm it up, push out the remaining liquid, and bring the shell above the dew point so that it doesn't sweat […]

Before the fighting starts about term definitions, let's just settle on using “adjustable drive pulley” and “sheave” interchangeably to describe the belt-driven power transmission device shown above. Second, for the newer tech, you shouldn't be altering these sheaves so that the belt rides lower or higher in them unless you know EXACTLY what you are […]

Grounding is an area of many myths and legends in both the electrical and HVAC fields. This is a short article, and we will briefly cover only a few common myths. For a more detailed explanation, I advise subscribing to Mike Holt's YouTube Channel HERE. Myth – Current Goes to Ground Actually, current (electrons) will […]

What should the delta T (ΔT) be? What do you mean!? 20 degrees, of course! We are referring to the air temperature drop across an air handling unit or evaporator coil in cooling mode. Actually, depending on who you ask, the answer will range between 18-22 degrees Fahrenheit. Heck, I’ve heard some insist that the […]

Do you know how a solenoid valve works? Really? On the surface, I think we all understand how a solenoid valve works. The coil energizes, creating an electromagnet. That temporary magnetism lifts an iron plunger within the valve allowing refrigerant to flow. But is it really that simple? It turns out that the answer isn't […]