Tech Tips

First, I want to give credit where credit is due. This post is made possible by the fantastic demonstration video by Neil Comparetto that I embedded below. Before you get bored and stop reading, I want to get the conclusion out in the air. Ice can form in a vacuum, but I still advise pulling a […]

Service valves are so basic, and we see them with such regularity that we can miss them altogether. Before I give the tips, I want to address the tech who tells the customer it was “probably the service valve” or “the caps were loose” as a plausible reason for a leak without actually making a […]

The following is based on a true story. No product was harmed in the making of this tech tip, and some facts may have changed to protect the guilty and because I forgot some of them. We got a job installing a new 1-to-1 split refrigeration case with R448a, and it had a typical thermostatic […]

The Four Ps of IAQ I’m not the first, second, or probably even the thirty-second person to write about improving indoor air quality problems using the four Ps approach. It’s a well-known thought process in the building science community—not sure if that’s the case in HVAC circles. The first P is for pollutants. In this […]

Most of the laws we refer to in air conditioning and refrigeration are pretty obvious and practical. Dalton's law of partial pressures is no exception. John Dalton observed that the air pressure was equal to the added pressures of each gas that make up air. That means that the pressure and density of air can […]

Diagram courtesy of Emerson New techs have a common question of how to wire a condensing fan motor for 3 vs. 4 wires. Jesse Grandbois submitted this tech tip to help make it simple. Thanks, Jesse! This tech tip is a quick one on the difference between wiring universal condenser fan motors and why brown […]

For those of you who use the MeasureQuick app for system diagnosis and performance testing, you may have noticed the “fan efficacy” results and wondered what it is. It is simply the CFM output of the system divided by the wattage used by the blower. It is only for the blower motor and has nothing […]

I've been reading a book called Cool: How Air Conditioning Changed Everything, and it got me interested once again in the history of air conditioning and refrigeration. Like many things, the people who are credited with “inventing” are the ones dogged enough to make an idea commercially successful, not the idealists forever tucked away in the […]

Photo Courtesy of Emerson What is Cascade refrigeration? “Cascade refrigeration” is a term you will hear more and more over the coming years, and while some of the systems may be very complex, the concept is actually pretty simple. Some refrigerants are well-suited for high and medium-temperature applications, and some are better suited for lower-temp […]