Tested vs Untested Louvers: Why Certification Matters
Most louvers on the Indian market are sold on a catalogue claim. A tested louver is sold on measured data. For any intake, facade or infrastructure project, that difference decides whether the louver actually performs — and whether it passes approval.
A “performance louver” only means something if the performance is proven. KBG's weather louvers are NABL-tested to BS EN 13030 and AMCA 500-L, so free area, pressure drop and water-rejection class are published per model. This page compares a tested, certified louver against an untested one on the criteria that decide a specification.
Tested (certified) vs untested louvers
The seven factors a consultant or EPC contractor actually checks — and how each option holds up.
| Criterion | Tested / certified louver (KBG) | Untested louver |
|---|---|---|
| Water rejection | ✓ Rated Class A–D to BS EN 13030 at a stated face velocity | ✗ Claimed, not measured — real rain penetration unknown |
| Free area | ✓ Published per model from lab test data | ✗ Catalogue estimate, often overstated |
| Airflow & pressure drop | ✓ Measured curve (AMCA 500-L) for accurate fan sizing | ✗ Guessed — risks under- or over-sized fans |
| Spec compliance | ✓ Meets the consultant's EN 13030 / AMCA spec; submittal-ready | ✗ May be rejected at the approval stage |
| Third-party evidence | ✓ NABL-accredited test certificate available on request | ✗ No independent evidence of performance |
| On-site risk | ✓ Predictable performance, defensible to the authority | ✗ Water ingress, noise or airflow failures found after install |
| True cost | ✓ Priced on verified performance you can rely on | ✗ Cheaper upfront — expensive if it fails or is rejected |
How to verify a louver's performance in 4 checks
Ask for the test report
Request the BS EN 13030 / AMCA 500-L certificate for the exact model, not a generic brochure line.
Check the face velocity
Water-rejection class only means something at a stated core face velocity — confirm it matches your design.
Confirm the lab
Look for NABL accreditation (or equivalent) — an independent lab, not an in-house claim.
Match free area & pressure drop
Use the published figures to size the opening and the fan — estimates here cause the real-world failures.
Louver testing & selection guides
Tested vs untested louvers — FAQs
What does it mean for a louver to be “tested”?
A tested louver has been measured in an accredited laboratory to a recognised standard — BS EN 13030 for rain rejection (Class A–D) and AMCA 500-L for air and water performance — so its free area, pressure drop and water penetration are documented figures, not catalogue estimates.
Which standards should a performance louver be tested to?
For weather/intake louvers, look for BS EN 13030 (water-rejection class at a defined core face velocity) and AMCA 500-L (air and water performance rating). For acoustic louvers, insertion loss should be stated per octave band to IS 9901 / ISO test methods.
How do I verify a louver manufacturer's performance claims?
Ask for the NABL-accredited (or equivalent) test certificate for the exact model you are specifying, at the face velocity of your design. A manufacturer selling on real performance will share it; one selling on price usually cannot.
Is a tested louver worth the extra cost?
For critical intakes, facades and infrastructure it almost always is. An untested louver that lets water in, chokes airflow or is rejected at approval costs far more to remedy than the modest premium for verified performance.
Specify with confidence — get the test data
Send your requirement and we'll return the BS EN 13030 / AMCA test certificate for the right model, with a quotation. India & GCC.