Luka recommends the following specification:
"Delivery and assembly in accordance with the Luka Quality Guide (latest version) with submission of a valid Luka Quality Certificate"

a. If there are requirements for the air transport route (including fittings), the delivery and installation of the air ducts, including fittings, must be carried out in accordance with the quality standards laid down in the Luka Quality Guide (latest version), whereby airtightness class "C" must be met as standard, in accordance with the latest version of the LUKA Quality Guide.

Registration on the certificate:
The production, assembly and mounting of the air transport systems, including fittings, have been carried out in accordance with the most recent Luka Quality Guide*.

and

b. If there are requirements for the air transport route (excluding fittings) the delivery and assembly of the air ducts must be carried out in accordance with the quality standards as laid down in the Luka Quality Guide (latest version), whereby as a standard airtightness class "C" must be complied with in accordance with the latest version of the LUKA quality guide.

Registration on the certificate:
The production, assembly and mounting of the air ducts have been carried out according to the most recent Luka Quality Guide*.

In both cases the airtightness must be checked and demonstrated by issuing a "Luka Quality Certificate".

* most recent Luka Quality Guide at the time of assignment.