Should Architectural Mechanical louvers be specified in Division 8 or Division 23?
Should Architectural Mechanical louvers be specified in Division 8 or Division 23? Which type of contractor should install them?
These are a few of the key questions prevalent in the Western Canadian construction market. This we have learned especially after working with General Contractors and other contractors.
We find that there is quite a bit of discussion as to who specifies architectural louvers. Is it in the scope of the architect or is it in the scope of mechanical engineer? It should be a combination of both because the Architect is concerned for the exterior design, aesthetics and code compliance of the cladding system. Mechanical Engineers will design the louvers for their air handling performance and rain defense for the HVAC systems that connect to the outsides exterior cladding.
So, if the consulting Architect specifies the louvres Division 8, after discussion with a mechanical engineer, the cladding or glazing contractors will usually bid on louver package. These contractors are ultimately responsible for the aesthetics and the building envelope performance of the building exterior. They want to include the supply and installation of louversas part of their cladding package. When keeping architectural mechanical louvres in their scope, this assures the building manager that the project will be run more efficiently, than if it is included in the HVAC sheet metal contractor’s scope.
Specification of Architectural Mechanical Louvers
Conversely, if the specifications for architectural mechanical louvers remain in Division 23 then, it could up the mechanical contractor or HVAC sheet metal contractor to include these exterior louvers in their package. This is something that they are reluctant to do for most HVAC contractors who do not like to work on the outside of the building and are not familiar with the technical details of measuring the rough openings for the submission of shop drawings.
Several times when reviewing drawings, I have had to ask what this “red X” is on building elevation drawings. The response from cladding contractors is that “oh, that is a louver supplied by the mechanical contractor”. We have even seen cases where louvers have not included in either contractors’ scope. So it becomes a scramble as to who supplies and installs them. In the worst-case scenario, we have seen plywood over the openings until the louver can be supplied mechanical/HVAC contractor and installed by the cladding contractor.
Rooftop vision screens around air handling equipment should also be handled by the cladding contractor. We have been involved with several cases where they were completely forgotten by the general contractor and so end up getting value engineered near the end of the job.
In conclusion, if architectural mechanical louvers are specified in Division 8 they will be included in the scope of the cladding or glazing contractor which usually ensures that the project will be completed on time as per the original contract.