Best way to seal exterior conduit
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What is the best way to seal within this type of exterior conduit? It is carrying wiring for the air conditioner. I was thinking of using duct seal compound, but I’m not sure that would hold up to outside conditions. The gaps between the wiring is a direct path of outside air and bugs to get into the home.
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When I installed a minisplit they sent a clay like substance similar to plumbers putty that I used. It was covered by a type of escutcheon plate that came with the penetration sleeve. There's always spray foam or caulk as well. I'd just plug it up with whatever you have that will last outside. Then cover it with an escutcheon plate or trim for good measure.
The "clay like substance" is duct seal. That stuff is commonly used for this sort of application, and it holds up pretty well outside BUT it does tend to eventually dry out and start to fall off in chunks (that usually takes a decade or three). What I would do is used canned foam to seal inside the hole, then put duct seal over the exterior part after trimming the canned foam overfill flush with the wall. Mould the duct seal around everything so that it is tight to the wall and conduit/cable. This gives you double layer protection against critters. I find that most critters have no problem chewing canned foam when they want to get through, but I have not seen any critters who like to chew through duct seal.
Bill