universalblue UBCA2002-21 User Manual page 24

 Decide where you want to install the duct. Consider that a
short, straight duct run will allow the hood to operate more
efficiently.
 Long ducts with elbows or transitions will reduce the
performance of the hood. As much as possible, use as few
elbows and transitions as possible.
 Install the duct. Connect the round metal duct to the cover
and then connect everything to the hood body. Use masking
tape to seal the joints between the duct sections.
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