Monitoring/supervising of Ducting Work of Contractor

[pakblogger2012]

Somehow I get involvement in supervising and monitoring of ducting work which is going on for one of our building.
I thought to have expert guidance and tips from you people about what to monitor and where contractor usually does dishonesty .
Please share wholesome guidance in above regard.
Thanks in advance.

[Brian_UK]

Simply compare the installation as it progresses with the design/install specification.

[still learning]

check they are using the size of duct they should be .
the joints are well sealed
the lagging is neat and tidy and taped on seams
and they are attaching it to the building with good supports .
see it does not pull apart or fall down.
good luck
hopefully you have a good team of contractors . if the job looks bad, then it may well be .
ductwork should be neat and tidy .

[pakblogger2012]

Few questions have just come to my mind.Please be kind to answer them.
If the duct is of size 12*8 then what size should we have for opening in the wall?
What should be noise level (in dB)/in office for providing comfortable working environment?
And what about velocity right at diffuser point?

[still learning]

ah, this is why i am a worker and not a boss.
he sizes all the kit.
is that 12 inch x 8inch duct?
how big is your fan and how long is the duct?