VARIABLE PITCH LOUVRE (VPL)
Zefyr variable pitch louvres are designed to provide the maximum air inlet capacity with minimum louvre face area - free inlet areas up to 75%. In the fully open position the louvre blades are contained completely within the louvre framework. When closed they have minimum air gaps preventing heat loss and draughts. Manufactured primarily in Versacor, the louvres can be installed as single units or banked either vertically or horizontally into cladding or brickwork.

Application
Horizontal blade operable box louvres manufactured from versacor, armacor, hp200 plastisol or aluminium. They can be used singly or in horizontal or vertical runs and can be fitted into openings in masonry, brickwork or cladding. They are suitable for applications where control of the airflow is required.

Installation
The VPL is bedded on to mastic sealant in masonry or brickwork and secured with flashings. They can be bolted or screwed to sheeting rails in cladding or secured with flashings.

Performance
The blade design has been tested for structural and aerodynamic performance to produce optimum spanning and pressure loss characteristics.

Box frame and blades
Frames and blades are manufactured from versacor protected metal. Embossed coloured finish in standard versacor, armacor, hp200 plastisol or aluminium. Other material specifications are available.

Blade pivots and bushes
Self-lubricating moulded nylon for long maintenance-free life.

Air Infiltration
Very little infiltration when louvres are in the closed position.

Birdguards and Insect Screens
Birdguards are available as an optional extra in galvanised, pvc coated galvanised steel or aluminium, or to suit customer's requirements.

Insect Screens are available as an optional extra in expanded aluminium small mesh type M901A (to BS1470:1987) or stainless steel wire mesh.

Note: birdguards and insect meshes will reduce the louvre free area.

CONTROLS
•   Manual winder handle or remote winder, pole operated.
•   Gas strut with cable and winch.
•   Remote electric actuator.

Standard heights and widths
See table. Non-standard widths are availabe

Measured Free Areas (in m2, blades horizontal)

Opening sizes
Individual louvres. Height +20mm. Width +20mm. Multiple banks - as above plus 5mm between each louvre box.

Flashings
Head, cill and jamb flashings can be supplied, where required, to suit customer's requirements.

Weight
17.5 Kg/m2