My master bathroom has two heating/AC ducts on the floor on opposite sides of the room.
I would like to move them from the floor to either the baseboard or just above the baseboard on the wall.
Anyone with any experience or suggestions on how to accomplish this?
Will moving the duct from the floor to the wall change the load?
Be sure to check the codes where you live. In my area, wall vents are apparently no longer to code, which I learned when the old asbestos laden furnace went away. So it had to be a floor vent.
Depends on how accessible the floor is and the direction of the floor joists.
If you can get down to the sub floor level it’s actually pretty easy to extend the duct between the floor joists till it hits the wall and have it terminate with a baseboard register.
On the other hand it could be rather difficult if you have to pull up ceramic tile / hardwood floor to get under the floor or have to run ducts through floor joists.
This is possible but difficult, even for someone who does this for a living. I’m not trying to discourage you, but you should be a pretty good DIYer to try this.
I assume that there is a basement underneath the bedroom?
If so, you need to determine where the wall is. This will not be evident from the basement. You can use reference points----like electrical wires that run up from the basement into that wall to get your bearings.
Drill a “pilot” hole with a very small drill bit to confirm/verify the positioning of the wall. Then you’d draw the rectangular hole you wish to cut on the underside in the basement. (I’d probably re verify once again the position of all 4 corners of my proposed hole with a tiny pilot bit before I’d bring out a 1" wood bit. You want to make sure that your new hole is 100% in the wall cavity. (read: 100%)
You’d then take a 1" wood auger bit and drill 4 holes----1 in each corner of the drawing. (If you spotted the wall correctly the auger bit will go up into the wall cavity and won’t be evident to your horrified wife upstairs…)
Than take a sawzall and open up the rectangular hole. Then the hard part comes. 
The ductwork----which was probably round to those registers----needs to be adapted for something called “wall stack.” The duct going into the wall is rectangular and it is made to be between studs.
Can you do this?
If you’re handy with the standard repertoire of power tools and can read a tape. Maybe yes. (the duct will be harder, believe it or not)
This is harder than a garden variety ceiling fan installation, but doable for some.
No, it will not change anything. (other than the location of the registers!)
This assumes that you use replacement duct that is equivalent in size to the duct being removed.
Can I hijack a bit since raindog gave such a good answer?
What about going the other way - baseboard to floor? I have a project coming up that involves moving a vent out of the way so I can have a sliding door installed. I’m not going to be doing it myself, but I’d like for the carpenter who installs the door to be able to do it. Is it much of a big deal?
It’s a carpeted plywood floor over a basement FWIW.
Thanks, Raindog. Your answer was very helpful.
Fortunately, the master bath sits above my basement garage, which doesn’t have a finished ceiling. I have access to everything from beneath.
I’m going to research a little more, but I have family that are builders/carpenters, so there shouldn’t be a problem with tools and “know-how.”
Can you give me an estimate in “days” (or hours) of how long you think it would take? On average, of course. I realize every situation is different based on construction variables.
I haven’t seen it but I would guess 4 hours per register. That includes spotting/cutting the hole underneath, cutting the hole in the wall, installing the register in the wall, adapting the duct and clean up.
It may go faster—and often it does----but if I was doing it (and ftr, I have) I’d allow 4 hours per register, and could possibly be done in 2-4 per register.
This is a much easier proposition.
The carpenter can do the floors----no problem. If he has no experience with duct/ sheetmetal it may be better to have an HVAC installer do that part of that.
Assuming that there is good access below the sliding door, it’s a lot easier to cut a register in the floor that find/cut in a wall register.
For an experienced person, cut the time I quoted The Composer in half.
One other thought…
In most construction projects the hard part for the DIYer is understanding the type of materials that any given trade uses for it’s craft.
Do you know what a “split bolt” is? An electrician does. With your projects, half the battle is selecting the right materials.
For the wall registers, “wall stack” will be used, and there is a wall stack “register boot” that will be inserted into the wall. Now the existing duct is probably round. But there is a “square to round” fitting that would allow you to go from wall stack to an existing round duct. Even then, there’s “straight boots”, “end boots” and “L boots”, all of which serve to confuse the newbie.
Theres no easy way to describe everything you need on a MB, particularly since I can’t see it. But the point is, selecting the right materials is 3/4 of the battle.
I just noticed that I said it was “1/2” the battle and “3/4” in the same post.
I’d consider it to be 5/8" of the battle to be safe, then.