Chimney-style range hood with a glass canopy over a cooktop

Generic photo: Bilguun Gantumur · Pexels License

Converting a range hood to recirculating (ductless) with the maker's kit: charcoal filter, deflector and where the air goes

Most convertible hoods go ductless with a kit from the same maker: one or more charcoal (carbon) filters that sit behind or on top of the grease filter, and for chimney-style hoods an air deflector or return grille so the cleaned air blows back into the kitchen. A short duct section connects the blower outlet to that deflector. The job is mostly fit and seal; the common mistakes are using a kit for a different model, sealing the outlet with the wrong tape, and leaving too little open area for the air to come back out. Tell the customer that ductless removes grease and some odor but not heat or moisture, and that the charcoal must be replaced on a schedule.

Single source ~45 min easyBrands: Bosch, Zephyr, Vent-A-Hood, All

Before you start

Turn off the hood circuit at the panel before opening the hood or chimney cover; Bosch's kit sheet says to lock out the panel
Do not seal or block an existing exterior damper in a way that leaves an open hole in the wall or roof; cap it properly

Diagnostic steps

Unlock all 5 steps with expected values

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