Read the inspection article: "Inspecting Uninsulated Exhaust Ducts in the Attic.”
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A home inspector in the article recommended insulating a bath exhaust duct without any evidence of condensation.
Any possible condensation at bath exhaust ducts is most likely limited to certain geographic areas and not a one size fits all fix.
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I agree. It is not a thing here in GA and will likely never be based on our climate. I’ll never call out a uninsulated bathroom exhaust without visible evidence of an issue (which I have never seen).
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From the propaganda article:
“An uninsulated duct is more than just a defect; it represents a significant building science failure that threatens the health of the home and its occupants”.
Some “home inspectors” make alarming claims for what reason? It’s never too late to learn. Home components behave differently in different climates.
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I guess it’s the “Chicken Little syndrome”.
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They think their value is heightened by drama.
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I think the artical is fine.
Just curious, how does insulating a bathroom exhaust fan improve energy efficiency?
This section appears to be directed towards supply and return ducts in unconditioned spaces. An exhaust fan is not a supply or return.
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In my area this is what a typical dryer vent looks like. There are no requirements, I’m aware of, to insulate bath exhaust vents.
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Chapter 15 appears to be the governing code for exhaust ducts. All the other code references from the NACHI article seem to be applied to conditioned supply and return ducts passing through unconditioned spaces.
This is also referenced in your article @bgromicko1 , but it pertains explicitly to underground ducts.
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Correct, but lacks info on sealing and insulating ducts passing through unconditioned attic spaces.
As the article states, there are building codes and standards that focus on heating, ventilation, and air conditioning (HVAC) supply and return ducts located outside the conditioned space. The underlying principle of those codes preventing heat loss and condensation applies equally to mechanical exhaust ducts.
That’s a stretch. How did you come to that conclusion? Each one of your reference codes speak of supply and return ducts in unconditioned spaces.
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I’m not here to argue or change your mind. One primary purpose of InterNACHI’s published articles is to function as the definitive, citable standard for the inspection profession. By linking to these official references in a report, an inspector substantiates their findings with the credibility of an authoritative, third-party reference. This practice elevates an inspector’s observation into an established finding for both clients and contractors.
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And I would also recommend repair of a hole in the roof without any evidence of a roof leak.
The article is a solution in search of a problem. It presumes, based on faulty correlations, that an uninsulated duct will sweat, and an insulated one will not. It makes no mention of a flex duct, which could more easily collect condensate than a rigid duct or pitching a rigid duct toward the outside.
It illustrates InterNACHI’s migration away from condition based defects to presumed defects based on code, or in this case, the misinterpretation of code.
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What is the reference for this? If there is one it might be in Energy Conservation, but I haven’t located it.
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A bath vent in warm humid areas (like south Florida) might be susceptible to condensation after running for an extended period. Although, I have never seen this after thousands of inspections where one of our protocols is to turn on the bath fans and allow them to run for extended periods.
I have seen (some) fresh air intakes insulated and pondered why they did that and what the benefit was of the insulated intake.
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