"Can anyone help me with directions to the ac guy to make this possible?"

Just give him the directions to your bank account.

Are you tied to one particular AC company? Have you checked with others? I moved a floor outlet on two occasions after we moved into our house. Obviously it will be some added expense on your end but seems like it would be possible. Depends on how much you want to move them :)

also- wouldn’t it be nice if people could skip the unhelpful comments ^ .

I’m only moving the vents a few inches over to the cabinet. Can anyone help me with directions to the ac guy to make this possible?

wouldn’t it be nice if people could skip the unhelpful comments ^ .

You have what sounds like hard sheet metal runs. These aren't flexible. So you depending on a wide variety of factors you may be looking at ripping out HVAC duct work and redoing it. (Why the contractor told you it's not feasible err in laymen's terms: it gonna cost a hoe chunk of money.)

Unhelpful comments vs people who want to do things not realizing the cost involved.

Anything is possible, provided your wallet is fat enough. Find a new AC guy when your wallet is full. (They're working in a crawl space... you chose not to do this as a profession and now you're gonna cry when someone else won't do it.)

Truth is stranger than fiction.

Helpful comments: please only tell us what we want to hear, devoid of reality. Sorry to hurt your ears with probable truth.

Is it just the one floor vent or do you have to move several? If it is one then perhaps you could change the cabinet layout to cover the vent. You could either install a bump out or a peninsula. If it is feasible then it is something to consider.

Are you keeping the wood floor? If is being removed and replaced then the moving the vent could be done from up above when the floor is redone. If you are keeping the floor then you will need to patch the hole in the floor. If the wood floor runs under the current cabinets then you can take boards from under the cabinet and use them them to cover the hole. Looking at the photo it seems the floor board stop at the cabinet. You may have another problem if the footprint of the new cabinets is not the same as the old.

If the crawl space is too small or too scary for someone to enter, then have the General Contractor hire someone to open the floor near the vent and underneath where the new cabinet will be located. The level of difficulty of moving new duct is dependent on the direction of the floor joists relative to the direction of the duct. If necessary a penetration through a joist should not be too difficult with the proper tools.

A good General Contractor should be able to figure this out a reasonable cost and make the finished product look good.

Thank you, Angela and Mike for the kind information and suggestions. I was under the house today and did see that the position of the floor joists could be a problem. The wood floor extends under the cabinets so I could use that wood to patch a hole, but I think they’d have to penetrate the joist, and I’d rather not take the risk of weakening it. So I guess I’m left with the floor vents—I’ll try to find something flush that we won’t stub toes on. 😊 I really appreciate the time and thought you put into your ideas and info, it definitely helped! Thank you!