System 4-35 Hi+ POV

High Performance Thermally Enhanced Parallel Opening Vent

Metal Technology’s System 4-35 Hi+ POV offers the designer a wide and diverse range of profiles that will provide structural integrity, weather performance, thermal enhancement and security.

Performance Overview

Weather Performance


Air Infiltration BS EN 1026

Class 4

Watertightness BS EN 1027

Class E750

Wind Resistance BS EN : 12211

Class E2400



BS EN ISO 140-3 and BS EN ISO 717-1


This system has been successfully tested to PAS 24 (using the annex C method) specification for "Enhanced Security Performance Requirements for Doorsets and Windows" as generally accepted on Secure by Design projects.

Size Limitation






Handle at



150 Kg



150 Kg


BREEAM Sustainability Rating

A Rating

Window Energy Rating

A+ Rating

Thermal Performance

Metal Technology's  range, in conjunction with the correct glass specification, is designed to aid compliance with the latest thermal requirements of the current building regulations. The polyamide thermal break profiles have been specifically designed to minimise heat transfer across the window profiles.

Thermal performance is further improved through the introduction of specially designed thermal gaskets and foam profiles. These reduce radiation heat loss across the air cavities within the window profiles to provide additional thermal enhancement.

  System 4-35 Hi+ U-frame values
4-35Hi POV 4-35Hi+ POV
Fixed light outer frame 1.92 W/m2K 1.34 W/m2K
Outer frame and glazed-in vent 2.57 W/m2K 1.69 W/m2K

The following table, based on a standard commercial GGF window configuration and warm edge spacers, demonstrates how such improved U-frame values then contribute to improving the overall thermal performance of a complete window.

Achievable whole
window U-value
Centre pane U-value
1.1 W/m2K 0.6 W/m2K
4-35Hi glazed-in casement 1.62 W/m2K 1.30 W/m2K
4-35Hi+ glazed-in casement 1.39 W/m2K 1.04 W/m2K


Metal Technology can provide tailored U-value calculations using their dedicated estimating software to calculate overall project average window U-values for their full range of systems.


Aluminium profiles are extruded from aluminium alloy 6060T6, T5 or T4 complying with the recommendations of BS EN 12020-2 / BS EN 755 Parts 1 to 9. Polyamide thermal breaks are produced from glass reinforced nylon sections designed to withstand temperatures in excess of 200°C, allowing the sections to be powder coated after thermally breaking.


Frame members are mitre cut at 45°, corners are reinforced with extruded aluminium crimping cleats and corner braces, and a secure joint is formed by pneumatically crimping into the extruded crimping cleat. Mullion and transom bars are square cut shaped and fixed securely to the frame by means of stainless steel screws and fixing cleats. All frame joints are sealed during construction against entry of water using Metal Technology’s two-part adhesive. Metal Technology recommend that only A2 or A4 Austenitic (300 series/class 70) stainless steel fixing screws are used in the assembly of their products.


The range of sections can be provided in either of the following ranges of finishes:

Anodised to BS 1615 or BS 3987 or BS EN 12373-1
Powder organic coated to BS 6496 or BS EN 12206-1
This system can accommodate a different colour finish internally to that used externally.
Metal Technology's powder coating is produced to Qualicoat standards.


The system can be glazed internally or externally and can accommodate glazing units from 28mm to 47mm.

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