How to cap this hood range exhaust vent?

[Patrick Irish]

I changed the range hood today with a ductless model. I went ductless because 105 degree air was coming through the old range hood. Plus it was really nasty and old.

How can I cap this duct and stop the hot air from coming in?

I kept the old flange/reducer if I HAVE to make the new hood ducted and connect it, it has the option to do both ducted or ductless.

[Lee Schierer]

I'm guessing that the duct goes up through the ceiling into an attic. You can remove the duct, patch the ceiling and add some insulation in the attic...no more hot air. However, there is probably more duct in the attic leading to a roof vent. You may also want to remove the roof vent and patch the roof to prevent future problems.

[roger wiegand]

Please don't remove it! If the next person cooks they will certainly want to reconnect the duct! You should be able to find an end cap at the Borg or heating/plumbing supply place. Seal it with some "real" duct tape (the kind that is UL approved for use on ducts, you find it in the plumbing area, not with the painters tape) to block air infiltration.

[Jim Becker]

I agree with Roger. Venting for cooking is an important thing for many folks and is missing in so many homes. Recirculation does nothing for removing vapors and heat...I'm struggling with this "as we speak" here in our new home and just bought a tiny camera on a wand to see if I can get venting to the outside through a soffit. Cap it neatly if you don't want to use it, but don't completely remove it. Someone in the future will appreciate that.

[Frank Pratt]

Sorry, but I'll pile on too. Going from vented to unvented is a huge backward step. You now just have a light over the stove. A properly installed vented hood will have a backdraft damper that will keep all that hot outside air from dumping in your kitchen

[Bill Dufour]

I agree install a damper and hook that vent up to the duct. I hope it is an electric stove so you do not get too much? CO.
Old school plug is a coffee can with some sheet metal screws and duct tape. Even tuper ware or plywood would be fine since it is not in use. Push mineral wool in a plastic bag and shove it up that pipe.
Bill D