#duct design

Tech Tips:

In my second year in HVAC, I went out with a senior technician to install a supply duct for a bathroom in a house. While he ran the duct, I cut a hole in the plenum and attached the collar. He crawled back across the attic and very nicely told me that people don’t typically […]

Manual D Speedsheet Walkthrough

Bryan recently released a podcast on rules of thumb and how they can really get us in a pickle with sizing ductwork. With that in mind, I thought this might be a good time to do a walkthrough of Manual D from start to finish on a project I just finished up. My good friend […]

How to Determine the Friction Rate for Residential Duct Design

This article is written by one of the smartest guys I know online, Neil Comparetto. Thanks, Neil! Recently, I posted a question in the HVAC School Group on Facebook that went like this: “When designing a residential duct system, what friction rate do you use?” As of writing this, only one answer was correct according […]

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In this short podcast episode, Bryan answers a listener-submitted question asking whether you can use another surge protector at the disconnect panel with an ICM 493 already in place.

Using multiple surge protectors in the configuration described does NOT count as daisy-chaining. Surge protectors with MOVs (metal oxide varistors) shunt current from high voltage to ground by reducing their resistance. MOVs are sacrificial, so they wear out over time. Surge protectors don’t last forever, so installing multiple is a fine idea.

You can have whole-home surge protection with additional surge protectors positioned at the appliances/electronics. While it can be done and doesn’t hurt anything, it’s not the most cost-effective solution.

When you install a surge protector, wire it in parallel with the circuit to ground. It should be wired properly with the shortest possible path to ground. In any case, many surge protectors won’t hold up against direct lightning strikes, but they will protect the equipment from power surges after power comes back on or constant overvoltage.

Our company, Kalos Services, now uses DITEK’s Kool Guard 2 as our surge protector and voltage monitor of choice. They also provide warranties for their products, which have come in handy for customers.

Learn more about the DITEK Kool Guard 2 at https://www.diteksurgeprotection.com/product-series/intelligent-voltage-monitoring/.

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