The jumper makes sense in some cases.
Gap under bathroom door for ventilation.
Check your bathroom door.
If the bathroom vent can t get any air of course it isn t going to work the right way.
If your door has very little or no clearance at the bottom you.
The flow dropped from an unrestricted 150 160 cfm down to under 100 cfm in each room.
This is less than desirable in bathrooms and bedrooms.
There is an approximately 1 5 gap at the bottom of the doors.
However the size of that gap is very unlikely to be greater than 1 2 for any door.
I like the suggestions for wall ceiling jump ducts etc.
My contractor just hung our fancy dancy un painted solid wood door slabs in my 100 year old house with solid hardwood floors throughout.
And for proper bathroom ventilation your exhaust fan needs to vent outside not into the attic or another area of the house.
7 mistakes not to make in your bathroom remodel do let your.
I have a problem with the door vents you are passively promoting.
I think it is too big and think a 1 4 1 2 gap would accommodate any unevenness in our floors and allow us to use area rugs.
Using the link you have provided it has a picture of a french full lite door with a vent that has removed a significant part of the door s base.
Client always resist 1 gap over the floor covering.
If more gap is required it is easier to trim a door than to lengthen it.