Thermally broken construction
Thermal separation through both the perimeter frame and individual blade holders makes BT90 well suited to conditioned façades and insulated-glazing applications.
Architectural Glass Louvres
BT90 Thermally Broken Glass Louvre System
A German-manufactured, centre-pivoting operable glass louvre system with thermally broken perimeter and blade framing for double-, triple- and selected single-glazed configurations.
BT90 uses individually framed horizontal glass blades within a 90 mm thermally broken perimeter frame. Each blade pivots through its centre, providing controlled ventilation while maintaining a framed insulated-glass appearance when closed.
A heavy-duty rack-and-pinion mechanism is concealed within the side framing and can be driven by a 24 V DC actuator as part of an automated natural ventilation, BMS or smoke-control system.
EBSA supports system selection, glass and façade coordination, automation, control panels, installation options, programming, commissioning and ongoing technical support.
System overview
Framed insulated-glass blades with centre-pivoting operation
BT90 is a commercial operable glass louvre in which each blade is contained within its own aluminium sash and pivots horizontally within a purpose-designed perimeter frame.
Thermal breaks are incorporated into both the perimeter frame and the individual blade holders, combining operable ventilation with thermally separated framing and insulated glazing.
The heavy-duty rack-and-pinion operating mechanism is concealed within the side framing, preserving a clean architectural appearance and allowing all blades to operate together as one coordinated opening.
Integrated blade operation
The concealed rack-and-pinion mechanism provides coordinated blade movement, positive closing and locking within the complete louvre assembly.
BT90 system features
- Centre-pivoting horizontally framed glass blades
- 90 mm thermally broken perimeter frame
- Thermally broken aluminium blade holders
- Double-, triple- and selected single-glazed configurations
- Concealed heavy-duty rack-and-pinion operating mechanism
- 24 V DC automated operation
- Positive blade closing and locking
- Suitable for natural ventilation and mixed-mode ventilation
- Suitable for integration with BMS and smoke-control systems
- Anodised or powder-coated aluminium finishes
Insulated glazing coordinated with the project façade
BT90 is primarily selected where a project requires insulated glazing within an operable louvre system. Glass construction is coordinated with the blade holder, louvre dimensions, design pressures, glass weight, safety requirements and wider façade glazing specification.
| BT90 configuration | Glazing accommodation | Typical application |
|---|---|---|
| BT90 IG32 | Double-glazed insulating glass units from 28–34 mm. | The standard BT90 configuration for H1 design, natural ventilation, mixed-mode ventilation and smoke-control applications. |
| BT90 IG44 | Triple-glazed insulating glass units from 40–44 mm. | Triple-glazed façade applications requiring increased insulated-glass depth. |
| Selected single glazing | Single glazing from 9.52–12.76 mm within the IG32 blade holder. | Selected façade applications where a framed single-glazed blade is appropriate. |
| Frame finish | Anodised or powder-coated aluminium profiles. | Selected to coordinate with the surrounding façade and project finish specification. |
Thermally broken framing for conditioned façades
BT90 combines thermally broken perimeter and blade framing with double- or triple-glazed insulated glass units, allowing the system to form part of conditioned façade and H1 design strategies.
Thermal performance is coordinated through the selected glass, overall louvre dimensions, frame-to-glass proportion, perimeter interfaces and installation arrangement. The selected BT90 configuration can then be incorporated into the project thermal assessment as part of the complete façade.
BT90 tested to SNZ TS 4211:2022 by ift Rosenheim
BT90 has been independently tested by ift Rosenheim to SNZ TS 4211:2022 using AS/NZS 4420.1:2016, including Amendment 1:2019. The full-size test programme covered serviceability, air infiltration, water penetration and ultimate strength performance.
The tested BT90 configuration measured 1500 × 2800 mm with six 1414 × 444 mm operable glass blades, a 32 mm insulated glass unit and automated 24 V DC operation with integrated locking.
| Tested measure | Result |
|---|---|
| Tested construction | 1500 × 2800 mm overall; six 1414 × 444 mm operable casements; 32 mm IGU; 24 V DC motor with integrated locking |
| SLS | +2500 / −2500 Pa; deflection below L/250 |
| Air infiltration at 75 Pa | +0.61 / −0.65 L/s·m² |
| Air infiltration at 150 Pa | +0.99 / −1.02 L/s·m² |
| Water penetration | 650 Pa; No Water Penetration |
| ULS | +6000 / −4000 Pa; Passed |
The full-size BT90 configuration demonstrated strong façade performance, including ±2500 Pa serviceability testing, 650 Pa with no water penetration and ultimate strength testing to +6000 / −4000 Pa.
Proven performance applied to project design
EBSA uses the independently tested BT90 configuration as the performance basis for project design, coordinating louvre dimensions, insulated-glass construction, supporting structure, frame fixing, actuator and locking forces, controls and façade interfaces with the required positive and negative project design pressures.
BT90 façade applications
Conditioned façades
Operable openings combining insulated glazing with thermally broken framing as part of the wider façade and H1 design.
Mixed-mode ventilation
Automated natural ventilation coordinated with mechanical building services, temperature and carbon-dioxide sensors, weather inputs, operating schedules and BMS commands.
Education and civic buildings
Schools, universities, libraries, community buildings and other commercial facilities requiring robust operable façade openings and coordinated controls.
Smoke-control applications
BT90 can be integrated into systems providing pressure relief, make-up air or natural smoke exhaust, with the louvres, drives and controls coordinated with the project fire and mechanical design.
Integrate BT90 with the building-control strategy
Automated operation is the primary configuration for BT90. A concealed 24 V DC drive operates the blades through the heavy-duty rack-and-pinion mechanism while the blade system provides coordinated closing and locking.
BT90 can be supplied with the D+H LDJ drive. The LDJ incorporates D+H ACB technology, enabling compatible control systems to provide real-time actuator monitoring, fault and status reporting, programming and remote technical support where the control architecture provides the required connectivity.
EBSA can coordinate the complete operating system, including control panels, local switches, environmental sensors, weather inputs, BMS interfaces, ventilation logic, fire-alarm interfaces, programming and commissioning.
- D+H LDJ 24 V DC drive option
- ACB actuator communication and monitoring
- Fault and operating-status reporting
- Remote programming and technical support where configured
- Local open and close controls
- Room-temperature and carbon-dioxide sensors
- Rain and wind protection inputs
- Mixed-mode and night-ventilation strategies
- BMS command and status interfaces
- Fire-alarm and smoke-control interfaces
- Control-panel programming
- Operational testing and commissioning
Configure the complete BT90 opening before manufacture
BT90 is configured for the individual project. EBSA coordinates the louvre arrangement with the façade, glazing, structure, controls and installation methodology before manufacture.
- Overall frame dimensions and blade arrangement
- Positive and negative project design pressures
- Glass thickness, makeup, weight, coatings and safety treatment
- Supporting structure, frame fixings and construction tolerances
- Perimeter seals, flashings, drainage and adjacent façade interfaces
- Required opening angle and ventilation free area
- Drive position, cable routes and control zones
- BMS, environmental sensor and fire-system interfaces
- Internal guarding or fall protection where required
- Cleaning, inspection and replacement access
Coordinate BT90 glass with the wider glazing package
BT90 can use suitable locally sourced glass. Glass may be supplied through the wider façade or glazing package or included within EBSA’s project scope.
Coordinating the louvre glass with the wider glazing package can align glass colour, coating and appearance across the building. EBSA provides the required blade-holder and glazing information and coordinates the proposed glass with the complete BT90 configuration.
From product supply to a complete operable-façade package
EBSA can be engaged for product supply, supported façade delivery, defined installation scope or a complete turnkey BT90 package.
| Delivery pathway | Typical EBSA role |
|---|---|
| Product supply | Project-configured BT90 system together with agreed product, installation and coordination information. |
| Supported façade delivery | Technical coordination with the builder, façade contractor, aluminium joiner or glazier on openings, glass, structure, installation, drives and control requirements. |
| Supply and installation | Louvre supply and installation, including glazing where included within the agreed EBSA scope. |
| Turnkey package | Design coordination, louvre supply, glazing coordination, installation, field cabling where included, control panels, programming, commissioning, handover and ongoing support. |
BT90 experience across education and civic façades
Completed BT90 installations demonstrate the system across commercial, education and civic façade applications.
Shore School, Sydney
Framed BT90 operable glass louvres integrated into the building’s glazed external envelope.
Brisbane Girls Grammar School
BT90 openings incorporated into an education façade and coordinated natural-ventilation system.
Lady Huntingfield Childcare Centre, Melbourne
Thermally broken framed glass louvres coordinated with the architectural façade and ventilation requirements.
Allow for project coordination and German manufacture
BT90 systems are manufactured in Germany to the approved project configuration. The programme should allow for design coordination, glass confirmation, production information, approvals, manufacture, international freight and local delivery.
- Confirm preliminary sizes and opening requirements
- Review the SNZ TS 4211:2022 performance evidence
- Confirm project SLS and ULS design pressures
- Coordinate the supporting structure and frame interfaces
- Confirm glass makeup and supply responsibility
- Select the drive and control-panel configuration
- Define sensors, BMS, ACB and building interfaces
- Complete coordinated drawings and project approvals
- Allow for manufacture, freight and local delivery
- Coordinate installation, glazing, cabling and commissioning access
German operable-louvre technology
Schneider Louvres technology supplied and supported by EBSA
BT90 is manufactured in Germany by Schneider Louvres. EBSA provides system selection, technical coordination, supply, automation, installation options, programming, commissioning and ongoing support for the system.
BT90 thermally broken operable glass louvre systems supplied and supported by EBSA.
BT90, MP2 SGI or LF550?
| System | Glazing and operation | Typical selection reason |
|---|---|---|
| BT90 | Thermally broken, centre-pivoting framed double- or triple-glazed blades. | Insulated glazing within a clearly framed, thermally separated louvre system. |
| MP2 SGI | Thermally broken, end-pivoting double- or triple-glazed blades with a structurally glazed external appearance. | Insulated glazing combined with a clean external glass expression. |
| LF550 | Large-format point-fixed single-glazed, end-pivoting blades. | A lighter, highly transparent louvre construction where insulated glazing is not required. |
Frequently asked questions
What makes BT90 thermally broken?
Thermal breaks are incorporated into both the 90 mm perimeter frame and the individual aluminium blade holders, providing thermal separation through the complete framed louvre system.
What glazing thicknesses can BT90 accept?
BT90 IG32 accepts double-glazed insulating glass units from 28–34 mm. BT90 IG44 accepts triple-glazed units from 40–44 mm. Selected single glazing from 9.52–12.76 mm can also be accommodated within the IG32 blade holder.
Has BT90 been independently tested for New Zealand façade performance?
Yes. BT90 has been independently tested by ift Rosenheim to SNZ TS 4211:2022 using AS/NZS 4420.1:2016 procedures. The full-size 1500 × 2800 mm configuration was tested for serviceability, air infiltration, water penetration and ultimate strength.
How did BT90 perform in structural testing?
The 1500 × 2800 mm BT90 configuration achieved serviceability testing to ±2500 Pa with deflection below L/250 and passed ultimate strength testing at +6000 / −4000 Pa.
How did BT90 perform in water testing?
The full-size 1500 × 2800 mm BT90 configuration achieved No Water Penetration at 650 Pa during independent ift Rosenheim testing.
What BT90 sizes are available?
BT90 dimensions are configured around the proposed glazing, glass weight, positive and negative design pressures, blade arrangement, frame fixing and supporting structure. EBSA uses the independently tested 1500 × 2800 mm configuration as the performance basis when coordinating project-specific systems.
How does BT90 support an H1 design?
BT90 combines thermally broken perimeter and blade framing with double- or triple-glazed insulated glass units. The selected glass and louvre configuration can be incorporated into the project thermal assessment as part of the complete façade.
What does the D+H LDJ drive add to the BT90 system?
The D+H LDJ is a concealed 24 V DC drive developed for the BT90 operating mechanism. With D+H ACB technology and a compatible control system, it can provide actuator communication, status monitoring, fault reporting, programming and remote technical support.
Is BT90 suitable for mixed-mode ventilation?
Yes. BT90 can form part of a mixed-mode ventilation strategy combining automated natural ventilation with mechanical building services. The system can be coordinated with temperature, carbon-dioxide, rain and wind sensors, schedules, local controls and BMS commands.
Can BT90 glass be supplied locally?
Yes. Suitable locally sourced glass can be coordinated with BT90, allowing colour, coatings and appearance to align with the wider project glazing package.
Can BT90 be manually operated?
Manual operation is available for selected applications. BT90 is primarily suited to automated operation where the louvres form part of natural ventilation, BMS or smoke-control systems.
Can BT90 form part of a smoke-control system?
Yes. BT90 can be integrated into smoke-control systems for functions including pressure relief, make-up air and natural smoke exhaust. EBSA coordinates the louvre, drive, control system and project interfaces with the fire and mechanical design.
What finishes are available?
BT90 aluminium profiles can be anodised or powder coated to coordinate with the surrounding façade and project finish specification.
When should BT90 be considered during design?
BT90 is best considered during façade design development so the louvre dimensions, glass, project pressures, supporting structure, drives, controls, façade interfaces and procurement programme can be coordinated before manufacture.
Discuss a BT90 glass louvre project
Contact EBSA to review the proposed opening size, glazing, façade interfaces, design pressures, automation requirements and project delivery strategy.
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