Arkansas HVACR NewsMagazine January 2026

News Magazine January 2026

FEATURE STORY

times. There was a limited understanding of the chemistry that informs many of our current best practices. There was less need to pull deep vacuums or flow nitrogen while brazing back in the day because we used chlorine-based refrigerants (CFCs and HCFCs). CFCs and HCFCs used mineral oil, which didn't attract water, turn to acid, or scrub cupric oxide off the tubing walls and gunk up filter-driers and valve screens.

Field practices must be supported by theory and an understanding of why . Getting in the reps helps, but it's not enough to understand how HVAC systems work and give customers the best possible comfort. The Ghost of HVAC Present looks like a jolly giant VRF system. It has at least three heads of varying capacities tied to a single outdoor unit. Some might find it intimidating and mistake it for a monster. Others make friends with it quite easily. (*Everybody collectively looks at Roman Baugh.*) Nowadays, we don't just have HVAC systems that turn on and off; we have compressors that can modulate to meet different load conditions (whether we set them up to do it effectively in humid climates is another matter entirely). We have fan speeds that can change. We have controllers that send signals between indoor and outdoor units to adjust their performance. Heck, we have heat pumps that work very well in Maine and even Norway , thanks to improved system and equipment design. We also have better tools: digital tools with fine resolution, probes that let us see refrigerant pressure and temperature readings on our phones 20 feet away, and apps that point out the red flags in our measurements. HVAC technicians are no The Ghost of HVAC Present Tools and Tech The tools and HVAC equipment have evolved a lot in the last decade or two.

As the industry has evolved, many of the practices that were fine twenty, thirty years ago are no longer so. Flowing nitrogen while brazing and pulling a deep vacuum is a MUST because of the POE oil used by HFCs and HFO blends. Beer can cold no longer cuts it for superheat (and really never did, but who doesn't still grab the suction line?). Simply knowing to feel for a certain temperature is no longer good enough; we need to know how to use P-T charts and understand what superheat and subcooling really signify to avoid making mistakes while charging (or blaming a perfectly fine TXV).