#leaks

Tech Tips:

What You Need to Know About Microchannel

Microchannel is a coil type used in many evaporator and condenser coils. You can easily identify it by its flat tubes, and its fins look like waves between the tubes. The technology was developed for use in the automotive industry and is used for radiators and automotive A/C condenser coils. These coils are made of […]

5 Simple Service Valve Tips

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 […]

Leak Detection – Spidey Sense

In this episode of the Spidey Sense series, Bryan and Bert dive deep into the art of refrigerant leak detection, sharing their wealth of experience and practical tips for HVAC technicians. They emphasize the importance of using one's senses and observation skills before relying solely on electronic tools, highlighting how this “Spidey Sense” approach […]

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How to Evacuate an AC system, Full Vacuum Procedure

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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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