Ductwork Leakage Class D

[RossThompson87]

Hi,

I am slightly confused as to why IES lets you select Class D for ductwork leakage.

Part L, DW143 & DW144 only mention classes A-C.

DW144 1998 Edition also states on page 5:

I should, however, like to take the opportunity to highlight a few topics which I believe to be of particular significance. They are:
the omission of high-pressure Class D (in order to conform to European practice);

This would suggest the class has been obsolete for over 15 years. Its not doing too much harm its just we have put it in a spec assuming it was a current standard based on the IES option. And now it is unclear what the contractor should do.

Ross

[Terence]

I'm not sure why that is available but I have asked our developers to review it.

[RossThompson87]

Hi Terence,

I spotted the other day that in the new Part L 2013 document, Class D appears in the table!

So it looks like it may be coming an active standard again? Perhaps its best to leave it in there.

Ross