What product evidence should be used?
Mestek Commercial Damper and Louver Group's article dated 6 May 2026 describes drainable blades directing water into jamb channels and onward to the sill. It also notes that severe weather can overwhelm a sill and discusses drain pans. These descriptions support checking the complete path; they do not establish a weather rating for a generator enclosure.
Use the selected louver's current drawings, installation information and approved enclosure design. Genset Enclosures is independent and is not affiliated with the manufacturer. Do not assume that every louver has the arrangement described in the linked article.
Sources: Mestek Commercial Damper and Louver Group: The Condenser: Proper Louver Drainage, 6 May 2026
Which drainage interfaces should be traced?
Mark each interface on the controlled section or detail and give it a drawing reference. The worksheet identifies questions for design coordination; it does not specify slopes, outlet sizes or installation methods.
| Interface | Evidence to locate | Question to resolve |
|---|---|---|
| Blade collection | Selected louver detail | Where does collected water travel within this product? |
| Jamb channel | Manufacturer drawing and frame arrangement | Is the documented path continuous in the assembly? |
| Sill discharge | Product sill and enclosure section | Where does water leave the louver? |
| Adjacent panel or opening | Enclosure elevations and sections | Does discharge interact with another opening? |
| Drain pan if specified | Approved detail and downstream outlet | Is its discharge path shown, rather than merely its name? |
| Maintenance access | Approved enclosure access detail | Can the responsible team inspect the specified drainage features? |
| Open design issue | Question reference, owner and approved response | Which interface remains unverified? |
What can a coordination mismatch look like?
Illustrative example. A fictional louver detail shows water leaving its sill, but the enclosure section places a projecting panel directly below that discharge. The drawing set does not show where the water then travels. Record the two detail references and ask the design owner to confirm the downstream path.
Do not add a drain hole, remove a panel or redirect the discharge as an informal drafting correction. Such a change can affect the approved enclosure arrangement. The designer determines the solution, and the drafting team records the authorized revision.
After the response, trace the revised path again and check adjacent penetrations and access details. Closing the sill question does not establish that all enclosure joints or openings satisfy the project weather requirement.
How is this different from a weatherproofing claim?
A path review checks the documents. A performance claim needs the relevant product and assembly evidence under the project requirements. Do not infer an enclosure rating from a louver brochure or from the absence of a visible gap in a drawing.
Keep rainwater separate from any fuel, oil or other containment requirements. Their design criteria and disposal arrangements are different questions for the responsible project team. This worksheet does not authorize mixing drainage systems.
Retain the selected product revision, marked section and resolved issue with the enclosure drawing pack. Engineering sign-off is performed only by the registered engineer on the job. Actual inspection and maintenance follow the approved site and manufacturer procedures.
Common questions
What else should the bid team know?
Does drainable mean no water can enter?
No. Verify the applicable product and assembly evidence against the project requirements.
Can a reviewer add an outlet to close the issue?
Only through an authorized design change, with the affected interfaces reviewed.
Does this worksheet set drainage sizes or slopes?
No. Those remain design inputs supplied and approved for the project.
Primary sources
- The Condenser: Proper Louver Drainage, 6 May 2026Mestek Commercial Damper and Louver Group