Smoke generator for HVAC testing?

Old 07-25-23, 07:32 PM
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Smoke generator for HVAC testing?

A return air duct for the furnace passes through the crawlspace. I want to check if this duct has a leakage that sucks air from the crawlspace. One way would be to light an incense and move it around the duct with the furnace blower on. But the incense produces very little smoke and it could take a long time to "scan" the duct. What is the next step up from an incense in terms of amount of smoke produced and is not harmful to breath in?
Old 07-26-23, 05:08 AM
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A cigarette would be an option. Or, just go down there and tape or apply duct putty to any seams or openings you see.
Old 07-26-23, 05:25 AM
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Wire-Pull technology (no lighter needed)
Up to 90 seconds of smoke
Numerous colors of smoke to choose from
Old 07-26-23, 08:39 AM
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Incense sticks work well if you don't mind the smell.
Old 07-26-23, 10:07 AM
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I usually use long wooden fireplace matches. Let it burn for a few seconds and blow it out, it creates a nice column of smoke to test for drafts. You can even reuse the same match a few times if you have a lighter.
Old 07-26-23, 10:17 AM
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I vote for taping it.

You could just get 2 ply toilet paper separate the plies and move it across the seams.

I do not know of any smoke that is not harmful
Smoke is particles in the air and lungs do not like particles!!!


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