If you have a basement or crawl space underneath the kitchen then you should be able to install a duct underneath the floor. It would be easier if the registers were installed in the floor, but if you are doing major demolition then a wall installation would not be too difficult.

Have you verified the this duct work does not supply any rooms on the second floor? You should investigate why the duct was installed at the ceiling and not below the floor.

It is very difficult to estimate a price. The duct work itself is not expensive, but there is quite a bit of labor involved.

Thanks very much, mike. Yes, there is a full basement under the entire
house with the exception of the garage. I am fairly certain this duct doesnt
supply the second floor bc this is a 2 zone house, and there is an air handler in the attic, but will certainly verify thanks for the suggestion.

I agree floor registers would be easier, but I understand it's more efficient
to have the registers as high as possible. Please correct me I this wrong. Not sure why the duct was installed here, it except that it was probably easier and in te 80s when this house was built kitchen soffits were the norm.

I am confused. In you first post you said the air handler is in the basement. In the second post you said it is in the attic. Where is it?

Sorry for the confusion. It's a 2 zone house, so there
is an air handler in the basement supplying this duct,
and an air handler is the attic presumably supplying
the second floor.

There is very little difference in efficiency with the registers built into the wall versus the floor. In your case it may be more efficient to have them in the floor.

If the ceiling joists of the kitchen are running in the same direction of the duct, then it may be possible to put the duct in between the joists. The duct would be narrower than what you currently have, but it may be sufficient. You could augment the air flow by installing toe kick registers in the new kitchen cabinets.

You want to hire someone who knows how to calculate the correct size duct work.

Thanks again, mike. Interesting that the placement of the registers
is not that important. In our last house we had a combo system, meaning the Forced hot air furnace was also the air handler. There were only one set of registers just above the baseboards and we were told the low placenent of the registers was not very efficient. It was a house built on the 60s.

I assume the joists run parallel to the duct bc that's the direction of the
Floor joists visible from the basement.

I was thinking to simply reuse this duct and reconnect to
to the registers for the dining room and living room, and
add three new registers for the kitchen to replace the exisitng registers
in the duct.

Thanks again

"I assume the joists run parallel to the duct bc that's the direction of the Floor joists visible from the basement."

I'm betting on just the opposite. Also, it appears the room(s) are much longer than they are wide... the the long direction length appears excessive for a single span. (I'm counting your 10" or 12" floor tiles to make that judgement.)

Use a stud finder on the ceiling to determine joist direction.

This post was edited by saltidawg on Fri, Jun 21, 13 at 12:18

Yes, you're right, saltidawg. I meant to write joists run perpendicular to the duct.

Yes, you're right, saltidawg. I meant to write joists run perpendicular to the duct.

If there is a difference , I would say floor ducts would be more efficient for heating and ceiling ducts more efficient for cooling ?

Wall ducts , some where in between , depending on height ?

God bless
Wyr

Thanks. That's always been my layman's understanding.