The DWL Exterior Dynamic Weather Louvre complements the SHX-UN universal pressure relief vents offering superior wind and weather protection without restricting the internal vents Free Vent Area (FVA). The DWL provides about twice the free vent area of fixed vane weather louvres used as standard within the HVAC market. Accordingly, specifying DWL can halve the number of units needed to deliver the required performance.

DWL louvres offer 98% wind seal, improved sound reduction and improved thermal rating compared to fixed louvres. Their performance is facilitated by thin but robust louvre blades that achieve up to 99% closing and offer protection from storm-blown rain, with reduced draft based heat loss from the building.

DWL Louvres, like all AFP products, have been thoroughly tested in our blast simulator. During testing in conjunction with SHX-UN units, the louvres were found to increase back pressure by only 10% during a gas suppression discharge. Because the AFP range of vents operates well below the projected peak pressure as calculated by the Vent Design Coefficient (vDc), this combination is still the most efficient pressure/blast relief product on the market.

Guaranteed quality with acceptance in many location worldwide.


  • NEXT DAY DELIVERY on all units if order is processed before 12pm
  • Weather tested with AFP wind & rain simulator – Report and video available upon request
  • Louvres are powder coated steel construction RAL 9006 Grey as standard, special colours available upon request.
  • Manufactured to ISO9001 and Russian GOST certification
  • The products carry a 5-year guarantee and are available ex-stock for next-day delivery if ordered before 12 pm
  • Can be retrofitted
  • The DWL comes with fitting kit and fitting instructions