Atrium Beam Smoke Detection

The Sefton Hotel, Douglas, Isle of Man

Client PALACE HOTELS GROUP, Douglas, Isle of Man
Sector Hospitality — heritage building, glazed atrium
Contractor Parfas Limited
Product Spectiv G8NB Reflective Optical Beam Smoke Detector
Application Multi-storey atrium / open void fire detection

Overview

The Sefton Hotel is a landmark seafront property on Harris Promenade, Douglas. At its heart is a striking multi-storey glazed atrium - open balconied floors rising to a pitched glass roof, filled with mature planting. This central void was the focus of the project: a fire detection challenge that conventional point detection could not solve well.

The challenge - protecting the atrium

The atrium presented every difficulty associated with high, open spaces:

Considerable ceiling height to a pitched glass roof, where smoke movement, cooling and stratification must be carefully considered when designing the detection strategy.
A large open void spanning multiple balconied floors, with limited practical ceiling surfaces for a conventional point detector layout.
A heritage-style interior with mature planting and decorative finishes, where multiple visible detectors, brackets and high-level cabling would have been intrusive.
Access at height within a live, guest-occupied hotel, making installation, servicing and maintenance more complex, costly and disruptive.

The project required a solution that could provide reliable detection across the open atrium volume while keeping visual impact and future maintenance requirements to a minimum.

The solution - Spectiv g8nb

Spectiv G8NB Reflective Optical Beam Smoke Detectors

Parfas specified and installed the Spectiv G8NB Reflective Optical Beam Smoke Detector to protect the atrium. The G8NB projects an infrared beam across the open area to a passive retro-reflector, monitoring obscuration to detect smoke rising through the void. A single detector covers a span that would otherwise require a large number of point detectors - ideal for exactly this kind of tall, open space.

Design Support

Spectiv supported Parfas during the design phase by reviewing the proposed beam locations before installation. This early design review helped confirm that the detector and reflector positions were appropriate for the atrium geometry and intended coverage strategy. It also helped ensure that the beams could be located discreetly and accessibly, supporting both the visual requirements of the space and the practical needs of installation and maintenance. By engaging at the design stage, Spectiv helped reduce installation risk and gave the contractor confidence that the chosen beam layout was suitable for the application.

Why the Spectiv G8NB

The Spectiv G8NB was selected because it addressed the key challenges of the Sefton atrium:

Wide-area protection: Each detector can protect a span of up to 100 m between detector and reflector, allowing large open spaces to be covered with far fewer devices than a conventional point detector approach.
Suitable for high, open spaces: Beam detection monitors across the protected void, making it well suited to atriums, glazed roofs and other open-volume environments where point detector positioning can be difficult.
Low visual impact: The compact detector and passive reflector could be mounted in discreet structural positions, helping preserve the appearance of the hotel interior.
Reduced access requirements: Fewer devices at high level means fewer future maintenance points, reducing disruption in a live hotel environment.
Configurable response thresholds: Selectable alarm thresholds of 25%, 35%, 50% and 75% allowed the system to be commissioned to suit the atrium’s site conditions.
Simple system integration: Volt-free fire and fault relay outputs allowed the beams to be integrated into the existing fire alarm system.

the Result

Reliable smoke detection across the full height and span of the atrium void.
Far fewer devices than a point-detector scheme — cutting install time, high-level cabling and ongoing maintenance access.
Minimal visual impact on a heritage interior, and minimal disruption to a live, guest-facing hotel.
Thresholds tuned at commissioning to suppress nuisance alarms while preserving early warning.

The Sefton Hotel atrium was the defining challenge of this project: a tall, glazed, open void within a live hospitality environment where conventional point detection would have been difficult to apply discreetly and efficiently.

By installing four Spectiv G8NB Reflective Optical Beam Smoke Detectors, Parfas delivered a clean, practical and low-impact detection solution suited to the geometry and visual sensitivity of the space.

Spectiv’s involvement at the design stage helped support the beam layout, while the installer feedback confirmed the G8NB’s ease of installation, alignment and commissioning.

The project demonstrates the value of the Spectiv G8NB in exactly the kind of high-ceiling, open-area environment it was designed for: atriums, hotel voids, glazed spaces, heritage interiors and other applications where broad coverage, low visual impact and practical maintenance access are essential.

“We found the beams to be really intuitive to install, line up and commission. It was a really simple process start to finish.”
Andy Chambers, Parfas Group