Range Hood to OTR Microwave - Vent Issues
We are installing an OTR microwave. There is an existing wall vent that was used for the range hood that is about 9.5 inches lower than the point where the microwave vent will be.
We are trying to avoid having to cut in a new vent on the outside of the house in which case the microwave exhaust would run straight out. We'd rather connect to the existing range hood vent using ducting.
We have removed all drywall between the microwave vent location and the existing vent so that there is an open space to hopefully work in some 3.25 x 10 ducting (2 elbows, 1 facing in and 1 facing out, with a short reach of duct between the elbows).
The studs are 2x4 so space b/w the outside wall and the inside wall is limited.
3.25x10 elbows purchased at Lowes are just too big and don't fit b/w the outside and inside wall.
We are not finding any elbows that would appear to fit and have done hours of searching on the web for this issue with no luck...even though this seems like it would be a very common problem.
Should we give up on the elbowed duct idea and just create a new vent directly behind the microwave and patch up the old one, or does anyone have suggestions for ducting?