Commercial HVAC & Refrigeration

Let’s take a deeper dive into the magic that is gas defrost. Most techs who are familiar with heat pumps understand the basics of a gas defrost. When we apply this strategy to a larger system where we’re only reversing a small part of the system, we need to add some controls and valves to […]

This article was written by Gary McCreadie from “HVAC know it all.” You can learn more about Gary and his tips and growing community on Facebook and LinkedIn. What is an economizer?  Simply put, it is a mechanical device designed to reduce energy consumption, whether it be fuel, electricity, or other. According to Wikipedia, the first […]

I know I’m gonna get some eye-rolling here, but it needs to be said. When we teach electricity to new techs, we use a lot of “water” metaphors. We talk about volts like PSI, amps like flow, and watts like GPM (speaking of GPM in HVAC, check out our article on hydronics HERE). Even the […]

If you work in large commercial offices or mixed-use buildings, you almost certainly work with VAV systems regularly. If you aren’t familiar with VAV, this is a quick intro to the basics so that they won’t seem so overwhelming. VAV stands for variable air volume; this means that the AHU (air handling unit) can vary […]

  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 […]

I heard a great presentation by Ron Auvil on VAV systems, and it got me thinking… Can you size a commercial system/perform a block load by the number of occupants? Yes!  No, I’m just kidding. That’s crazy talk. There is way more to it than that. However, in a commercial environment, while the building’s perimeter […]

This article is a quick, real-life diagnosis/find by Kalos Services senior commercial HVAC/R tech Eric Mele. Improper Defrost Timer installation While servicing this display cooler for an unrelated problem, I noticed the defrost timer installed in a way that will almost certainly cause early compressor failure. Because this is a cooler (not a freezer), it […]

Whenever there is a conversation where “code” is involved, it’s important to mention that codes can vary depending on the AHJ or authority having jurisdiction. It’s becoming more common for governments to lean heavily on the ICC (International Code Council). In the case of HVAC/R, that is the IMC (International Mechanical Code), and in the […]

Remote Ice Machines Why would someone want to take an already complicated machine and make it even more complicated? The answer: human arrogance and engineer’s hubris. (Just kidding.) Fortunately, thousands of these ice machines have been installed and serviced. Let’s take a little overview of a few of the critical differences and things to consider […]