#natural gas

Tech Tips:

Gas Furnaces – What a Tech Needs to Know

It’s that time of year again—the furnace service calls are peaking. It’s a good idea to crack open Jason Obrzut’s book, Gas Heating: Furnaces, Boilers, Controls, Components, and listen to the many public podcasts and presentations by experts like Jim Bergmann. At HVAC School, we’re fortunate to have had some of the industry’s greatest minds […]

Clocking a Gas Meter (It’s not that hard)

I've heard a lot made of clocking gas meters over the years, and honestly, in Florida, there isn't too much call for heat. There are even fewer furnaces. I was pleasantly surprised when I found out how easy it actually is. Here is how you do it, step by step: #1 – Make sure all […]

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#clocking meter #furnace #natural gas

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HVAC School – For Techs, By Techs

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

In this short podcast episode, Zach joins Bryan to answer a common duct maintenance question: Should I fog or sanitize my ducts?

The North American Duct Cleaners Association (NADCA) outlines the uses of chemical products. Adding chemicals is usually a last resort in flex or sheet metal (externally wrapped) duct systems; they should NOT be used on ducts with internal liners or are made of duct board or any other material with porous surfaces.

Fog is typically applied while a vacuum is running at the opposite end of the duct. It liquefies on surfaces, and a lot of contractors don’t go in and dry off the duct surfaces. It’s difficult to coat the entire interior of a duct system with the chemical to make it as effective as possible, and the residue creates a moist, sticky film that actually encourages microbial growth in the ductwork. On top of that, some people may be sensitive to the chemicals.

In many cases, replacing ductwork that has been confirmed to have microbial growth is more reliable. Chemical duct sanitation often has more of a perceived benefit than long-term results. The use of chemical cleaners in ductwork is similar to that of using some line set flushes without forcing a solid pig through the line set to pick up the residue afterward. Ultimately, the customer has to make an informed decision based on the problem and knowledge of the benefits and drawbacks of chemical solutions.

NADCA’s white papers, including “Chemical Product Applications in HVAC Systems,” are available at https://nadca.com/industry-professionals/nadca-white-papers.

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