Alloy finish moisture reduction grille
Alloy finish moisture reduction grille

Air Intake Grilles

Teardrop shape engine room grille
Black teardrop shape grille
White engine room ventilation grille
Gloss white powder coated grille

Salt spray and mist in your engine room has traditionally been one of the most difficult issues to control. Now with Marine Air Flow moisture reducing air intake grilles, you can remove the problem altogether.   

Damage such as blown turbo's, blocked air filters, wide spread corrosion and degradation of your valuable engine room equipment can now be avoided.

Some Features:

  • Reduces Damage to valuable plant and engine room components.
  • Custom made to suit your requirements.
  • No moving parts.
  • Supplied with full installation kit and instructions.

How They Work:

Engine room intake grille diagram

Using engine induction or engine room fans, the moisture laden external air supply is drawn through our grille, passing through a complex system of vanes in the process. This action removes the moisture laden molecules from the air, leaving behind a considerably fresher air supply inducted into your engine room. 

Air is drawn into the face of the grille. The moisture laden air then passes through a system of vanes which trap the moisture in the air and cause it to run vertically down the face of the vanes and then be expelled via the external drain. The moisture reduced air is then fed into your engine room for use by your engine and other components. The vanes are sufficiently complicated to trap the moisture, but no so complicated that they significantly slow the air flow.

Performance Data:


Performance - Single Grille

Water handling 250 litres /min over 1m 2 area
Max face velocity 5.9 metres / sec
Efficiency 100% visible

Performance - Double Grille

Water handling 250 litres /min over 1m 2 area
Max face velocity 9 metres / sec
Efficiency 100% visible

Finished product details:

Fins / Vanes Extruded aluminium vane section welded into position.
Surround Aluminium to 6106T6 grade. Fully Welded.
Supplied finish Acid stripped and dipped. Fully imersed chromated & powder coated to chosen colour.
Painting Can be painted to suit, however we don't supply the grilles painted.
Yes - On request.

Pressure Loss & Water Removal

Our pressure loss is significantly more efficient than some other manufacturers. We acheive less than 120pa drop at a face velocity of 5.8 metres per second. 1 This means better efficiency for your fans and engine room equipment. The finished grille has been tested at excess of 250 litres per minute per 2 m with effective removal of all visible water.

1 Independantly Tunnel tested by UniQuest


Marine Air Grilles


Air Grilles for cruise vessel
Atlantic Princess

Air Grilles for the cruise vessel Atlantic Princess.

Custom Shaped grille with dorade
Custom shaped grille in black

Custom shaped black grille for Aqua Marina

Teardrop shaped air grille
Teardrop shaped grille

Flange Info:

We have three flange options the details of which are below: All these options have a fixing flange of 40mm & a face flange of 25mm.

Flush Flange:


With this option the fixing flange is flush to the outside face of the grille. Once installed only the 3mm thickness of the flange protrudes outside of the vessel. 100mm of the grille thickness extends into the air ducting, reducing the airway by 100mm. The drain slots on this assembly are totally visible to the exterior face.

Flush flange for engine room grille

Stepped Flange:


With this option the grilles extends 30mm to the exterior of the vessel and 70mm protrudes into the air ducting. On this assembly the drain slots maybe mounted on the underside edge and thereby are not easily visible. This acheives a more aesthetic external appearance.

Stepped flange for air intake grille

Limited Flange:


With this option the grille extends 70mm to the exterior of the vessel and only 30mm protrudes into the air ducting. This acheives the least restrictive passage within the air ducting. It is recommended that this arrangement is utilised in any restricted airway so as to maximise air flow.  

Engine room grille with limited flange

Fixing Flange:


The fixing flange is 40mm.

Fixing flange on the air grille

Single & Double Stage Grille Setups

Single Stage Grilles:

Single stage air grille diagram

Marine Air Flow International single phase air grilles are designed to stop the induction of salt spray and moisture laden air into your engine room. Our grilles will allow air to pass at up to 6 metres per second,  with very minimal air pressure loss. 

Most water induction problems can be solved with this single stage unit.

Single Stage With Filter Media

Single stage air grille with filter media

For situations where you have the same problems with moisture induction but with the added issues of dust, insects, sand and particulate also being injected into your engine room space, we can add a specialised filter media to the face of your grille to eliminate these additional problems. These type of setups are typically called "Two Stage" grilles.  

Double Grille With Filter Media

Double stage air grille with filter media

When you require higher velocities and bigger quantities of air a double stage grille is required. These consist of two air grilles with a mounted filter media situated between the two grilles. When you exceed the recommended air velocity moisture is inevitably drawn through the primary grille. The excess moisture then hits the intermediate filter media and condenses to much larger drops, some of which are removed via the drains. The remainder of the moisture particles are then removed by the second stage grille. These type of setups are typically called "Three Stage" grilles.


Air intake grilles are available from $1200 + gst. The size of the grilles is dependant upon varying factors, and of course the size required to ensure accurate operating air supply is the governing factor in our pricing structure. We can also manufacture the grilles in almost any shape and offer complete engine room ventilation systems.  

The things you will need to know for this process are:

  • The number of main engines in your vessel.
  • The total horsepower of these main engines.
  • The make and preferably model of your engines. (Not essential but preferable.)
  • The horsepower of any generators you may have in your engine room.
  • The shape of your grille penetration.
  • The area of your grille penetration -   or   -
  • The height & length measurements of the penetration so we can calculate the area.
  • The volume of your engine room -   or   -
  • The height, width & length measurements so our web site can calculate this area.