Repurpose abandoned ductwork?
steve_smith
| Posted in General Questions on
About 18 months ago I finally installed a couple of ductless minisplits in my ~1600sf single story house. The furnace and ductwork were located in an unconditioned attic. Is there any potential utility in repurposing the existing ductwork or are there too many energy penalty (or other) downsides to running anything through an unconditioned attic?
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Replies
I'd vote to recycle the metal and toss the furnace. The ducts likely are full of dust and hot air "debris" and would not be good for re-use. You might want to air seal your attic while you're working up there; it'll help make your house much more comfortable.
If you aren't running your old ducted system, I can't really see what else those ducts would be good for. You could potentially run communications wiring through them, but I don't see what other purpose they could potentially have. Removing them and selling the metal for scrap is probably your best option, then seal up any old duct penetrations through ceilings or walls and fill in any remaining voids with new insulation.
Bill
I considered running an ERV or whole house air purifier set up through the ducts, but I have seen recommendations against those ideas due to the energy penalty of running anything through unconditioned space.
Can we assume you sealed the ceiling vents connecting the abandoned duct work to the conditioned spaces?
Filling the ends of the ducts with insulation and patching the drywall and repainting would be best but it is a lot of work.
Walta