I just bought a stacking washer/dryer machine and I need to relocate my floor dryer vent by 3ft above the floor so that I can push my machine all the way against the wall. This will give me about 7in of extra space in my laundry room. My floor vent is behind the wall and vent through the roof. It is 10x3.25 size rectangular tube and it's pretty much stuck to a stud.
One option is to cut the rectangular vent tube at a 3ft location and add a stack boot. But I am not sure how to seal it since the stud is right next to the tube and no space for me to wrap the tape around to seal it.
I think the easiest way is to punch a hole at 3ft location and add a 4" opening for the dryer. And seal off the floor vent. This will be much less cutting and easier to seal. However, this setup creates T or Y like connection. Dryer air will flow in two directions, up and down. Air flows downward by 3ft but it's blocked at the floor. And also flows upward to the roof (25ft) and exit. Is this an OK setup or will create issues?
Thank you so much in advance for any advice.