AFDL-N to suit 38-44mm thick doors and AFDL-W to suit 45-55mm thick doors.
35.8° from vertical.
Mesh cannot be used with expandable frames.
FREE AIR FLOW
50% free area. (36.6% when using insect mesh).
It is self-attaching through the cut-out in the door using No.8 Phillips head sheet metal screws through countersunk mounting holes to attach the auxiliary frame to the louvre core, thus eliminating the need to drill holes in the door. This method saves time and installation labour and leaves the corridor side of the frame free of fasteners for added security, and a cleaner aesthetic appearance. Given that there are now three versions of this louvre to suit different door thicknesses (see AFDL-N and AFDL-W), two different screw lengths are supplied with them.
These are supplied with the louvres. Optional Snake eye or Torx screws are available for applications where security is required on the external face.
% FREE AREA
The free area of a louvre is an approximate percentage based on the open area between the blades through which air can pass. The percentage free area has long been used as a convenient means to select louvre type and size but is not an indicator of the louvre's performance (air flow rate).
LOUVRE AIR FLOW
We often get asked to confirm the air flow rates of both the AFDL and FDLS louvres. This can be calculated, but there are a number of variables that are required in order to do so. These are as follows:
- Volume of air in cubic metres per second. This is usually specified as a minimum requirement value.
- Desired air speed/pressure, usually in miles per hour/pascals.
- Louvre type and size.
Using the above criteria we can determine the airflow for a specific size louvre, or the louvre size required to achieve a specific airflow. There is a useful louvre pressure drop calculator on the information/videos tab at www.anemostat.com/doorproducts.
ORDERING FRACTIONAL SIZED LOUVRES
Please note that if fractional inch sized louvres are required, the outside frame dimension is increased to accommodate the odd size. As only complete blades can be used when making louvres, the maximum number of one inch blades is calculated from the cut-out size and any surplus added to the outside frame dimension. If fractional sizes are required and the outside frame dimension is critical, please contact us for exact overall frame sizes prior to ordering. We would always recommend ordering the metric equivalent of exact inch size louvres, although any fractional size is available.