500 BTUs per Person Per Hour?
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 […]
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Capacitors – Series and Parallel
Knowing how to combine capacitors in series and parallel properly is a great practical field skill to employ when you need to get a customer up and running, but you don't have the exact size. Increasing in size is easy. Just connect in parallel and add the two sizes together. For example, if you needed […]
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Walk-In Cooler Defrost
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 […]
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Storming the Gates to Trade Education
Before we jump into the stuff that will make folks angry, let's start with some common ground. Most of us can probably agree that the desired result of education in the trades is: Knowing what you are doing and doing it as safely, efficiently, and correctly as possible. If we can agree that we all […]
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Humidifier Facts
Humidifiers are a big part of HVAC systems in dry locations, especially in the winter. I have no experience with them personally because they aren't prevalent at all in Florida. I asked some of the HVAC School contributors to weigh in with some of their top humidifier tips. Thanks to Nathan Perney, Steve Domansky, and […]
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Checking the Charge Without Gauges (Our Process)
This is an internal guide we use at Kalos, and it works for our climate and the type of HVAC equipment we work on. Consult with your company leadership before implementing this or any process. Keep in mind that some of these guidelines are “made up” by me and are only useful in the absence […]
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Condensate Drainage in a High Efficiency Gas Furnace
This article was written by HVAC/furnace technician Benoît Mongeau. Thank you, Ben.     High efficiency (or 90%, or condensing) furnaces use a set of two heat exchangers to retrieve more heat from the combustion products than their mid-efficiency counterparts. Because of this, they generate flue gases much colder than those of a mid-efficiency or […]
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Duct Smoke Detectors/Alarms and the Code
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 […]
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VRV Operation
This tech tip is written by experienced tech and VRF / VRV specialist Ryan Findley. Thanks, Ryan! (Note: Ryan refers to VRV rather than VRF because he specializes in Daikin, and these articles are written from a Daikin VRV perspective. Ryan has also written an article about VRV basics and some VRV installation tips.) This […]
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