"Jack" wrote in message ...
I am finishing my basement. I have a main trunk running down the
center of the house. It looks like it can be raised up about 4 inches to
snug up against the first floor joists. I need all the headroom I can
possibly get.
.
Can this be done? Any idea on cost (I know this is an unfair question).
I
am guessing I need some sort of transition boot where the duct would get
cut. Would this cut air flow if a transition was put in? I don't have
much
HVAC experience, but it doesn't seem like this would be a huge job.
.
Thank you for your time.


It would be much easier to leave the duct in place and install the ceiling
the height you want and cover or paint the duct to blend it in. Raising the
trunk normally requires a lot of reworking to hook the runs back up to the
trunk unless you home has flex duct. And if you have pipe in place it is not
wise to replace it with flex duct. Installer normally try to run the trunk
as close to the members as they can while still leaving enough room to get
the drops and runs off the trunks. You need to look at what it will take to
hook the runs and drops backup before you commit, raising the trunk isn't
the difficult part. You can have a sheet metal shop or HVAC contractor come
out to measure and fabricate a new transition, if properly made the static
lose will be minimum. I'd be more concerned with what you might have to add
in the way of fitting to reconnect the runs.