The N2 Gen approach: How DSPA supports reliable protection in modern infrastructure
Iain Hoey
Share this content
John Munno, Director of Energy Risk Engineer, explains how nitrogen generation technology improves safety, efficiency and compliance in modern energy facilities
The energy sector encompasses a range of high-value, mission-critical assets vulnerable to fire risks, including energised electrical equipment (Class C per NFPA 2010), flammable liquids and gases (Class B) and ordinary combustibles (Class A).
Facilities such as power substations, transformer enclosures, battery storage rooms and control cabinets require fire suppression solutions that are non-conductive, residue-free and safe for sensitive electronics.
Inert gas systems, particularly those based on nitrogen (IG-100), extinguish fires by reducing oxygen concentrations to below 15% while maintaining breathable levels above 10%, making them ideal for these applications.
High-pressure cylinder-based systems have dominated this space for decades, storing compressed nitrogen in steel cylinders released via solenoid valves and piping networks.
However, emerging technologies like the N2 Gen by DSPA – a non-pressurised, electrically initiated nitrogen generator – provide innovative alternatives.
By generating nitrogen on-demand through controlled decomposition of a solid compound, N2 Gen eliminates many limitations of cylinder systems.
This paper explores these advantages, drawing on technical specifications and performance data to demonstrate N2 Gen’s suitability for energy-related risks.
How cylinder-based systems operate
High-pressure cylinder-based systems store nitrogen or inert gas mixtures (e.g., IG-100, IG-55, or IG-541) in seamless steel cylinders pressurised to 200-300 bar (2,900-4,350 psi).
Upon fire detection, a control panel signals the release of gas through discharge nozzles via fixed piping, flooding the protected enclosure to achieve design concentrations (typically 40-52% by volume for nitrogen, equivalent to 12-15% oxygen reduction).
Key features include:
- Rapid Discharge: Full release in 60-120 seconds, depending on system size.
- Distribution: Requires engineered piping for even agent dispersal.
- Maintenance: Periodic hydrostatic testing (every 5-10 years), pressure checks and cylinder recertification.
- Applications: Widely used in data centres, electrical rooms and energy facilities for total flooding protection.
While effective, these systems involve challenges such as high initial costs for cylinders and piping, space-intensive storage and safety risks from high-pressure vessels, which can rupture under impact or corrosion.
How the N2 Gen system works
The N2 Gen by DSPA is a fixed fire suppression generator designed for enclosed environments, producing pure nitrogen (IG-100) through an irreversible chemical reaction.
Housed in a stainless-steel enclosure, it contains a solid propellant that, upon electrical activation from a fire detection panel, an initiator triggers decomposition, generating nitrogen gas that passes through a multi-layer filter/cooler to remove particulates and cool the output.
Technical specifications include:
- Discharge Time: 5-14 seconds, providing rapid flooding.
- Agent Output: Scalable based on generator size, achieving oxygen reduction below 13% in enclosures that retain gas for at least 10 minutes.
- Placement: Can be installed directly inside the protected area (no piping needed) or externally with optional hoses.
- Outer Casing: Provides thermal clearance (air gap) to limit surface temperatures to 75°C for personnel and 200°C for combustibles, with perforations for even gas distribution.
- Certifications: Tested for Class A, B and C fires per EN 2 and NFPA 2010 standards; suitable for unoccupied energy assets like industrial units and storages.
- Limitations: Irreversible activation; not for deep-seated fires or oxidising materials.
N2 Gen’s design ensures clean, transparent, non-conductive discharge with no residue, preserving visibility and equipment integrity – critical for energy applications.
Comparing N2 Gen and cylinder designs
The N2 Gen system’s solid propellant technology offers significant benefits over cylinder-based systems, particularly for energy-related risks where space is constrained, reliability is paramount and rapid response minimises operational disruptions.
Enhanced safety
High-pressure cylinders pose inherent risks, including potential rupture from mechanical damage, corrosion, or over-pressurisation, which could lead to explosive failure in seismic or impact-prone energy sites.
N2 Gen operates at ambient pressure until activation, eliminating these hazards.
Its hermetically sealed stainless-steel housing ensures a 15-year shelf life without leakage concerns and the generated nitrogen exhaust is non-toxic (primarily N2 with trace CO2 and H2O).
In energy facilities, where personnel may enter intermittently, N2 Gen’s thermal safeguards (e.g., air gap limiting exposure to safe temperatures) provide superior protection compared to cylinder systems, which require secure storage to prevent accidental discharge.
Easier installation in compact sites
Cylinder systems demand substantial infrastructure: multiple heavy cylinders (each 50-100 kg), extensive piping networks and dedicated storage rooms, complicating retrofits in compact energy enclosures like switchgear or battery rooms.
N2 Gen’s lightweight, compact design (25-50% the weight of equivalent cylinder agents) allows direct placement within the risk area, eliminating piping needs and reducing installation time and costs by up to 50%.
For external mounting, flexible hoses suffice.
This modularity is ideal for modular energy assets, such as offshore platforms or containerised substations, where space savings translate to more efficient layouts and easier compliance with tight enclosure standards.
Lower maintenance and cost efficiency
Cylinder systems require ongoing maintenance, including annual inspections, hydrostatic testing every 5 years and periodic refills, incurring high operational expenses – especially in remote energy sites.
N2 Gen has minimal maintenance needs: visual checks and electrical testing of the initiator, with no pressure monitoring or recertification.
Long-term costs are further reduced by avoiding cylinder transport and disposal.
Initial capital outlay for N2 Gen is competitive and its scalability (multiple units for larger volumes) avoids over-sizing, providing ROI through reduced downtime in energy operations where fires can cost millions in lost production.
Superior performance in energy applications
Both systems use nitrogen for oxygen reduction, but N2 Gen’s rapid 5-14 second discharge generates inherent momentum for better distribution in cluttered enclosures, outperforming slower cylinder releases (60+ seconds) that may be hindered by piping friction or venting.
In energy risks – e.g., arc flashes in electrical panels or gas leaks in compressor stations – N2 Gen’s quick action prevents escalation, with testing showing effective suppression at 12% oxygen levels even with internal airflow.
Its filter ensures particle-free output, safeguarding sensitive turbines or transformers from contamination, unlike potential impurities in stored gases.
For hazardous areas (per ATEX Directive), N2 Gen’s non-pressurised nature simplifies approvals.
Environmental and reliability benefits
Cylinder systems contribute to emissions via manufacturing and transport of high-pressure vessels, while N2 Gen’s on-site generation minimises logistics footprints, aligning with sustainability goals in the energy transition.
Reliability is enhanced by N2 Gen’s rugged design (-20°C to +75°C operation, 95% humidity tolerance), resisting corrosion in humid or coastal energy environments where cylinders might degrade.
Post-discharge, N2 Gen leaves no residue, enabling immediate equipment restart – vital for grid stability.
Technical comparison of suppression methods
Traditional high-pressure cylinder systems store extinguishing agents at 200–300 bar, while the N2 Gen by DSPA system operates at ambient pressure (0 bar).
This low-pressure design removes the need for heavy storage vessels and reduces overall system weight by up to 75% for an equivalent agent volume.
The systems also differ in performance and installation.
High-pressure cylinders typically discharge over 60–120 seconds, whereas N2 Gen units complete discharge within 5–14 seconds.
Because N2 Gen systems require no fixed pipework, units can be positioned directly in the protected area, streamlining installation and enabling flexible system design.
Maintenance demands are lower for N2 Gen, limited to visual or electrical inspections, compared with the annual servicing and five-year pressure testing needed for high-pressure systems.
The operational lifespan extends to 15 years, whereas conventional cylinders generally require replacement or retesting after 5–10 years.
In terms of space, high-pressure systems occupy a larger footprint due to cylinders and storage requirements, while N2 Gen offers a compact configuration, providing a practical solution where space efficiency and ease of maintenance are priorities.
Applications in the energy sector
N2 Gen excels in protecting energy infrastructure, such as:
- Substations and Switchgear: Direct installation in enclosures guards against electrical faults without residue.
- Battery and Transformer Rooms: Rapid response to thermal runaway or oil fires.
- Gas Storage Modules: Suppresses Class C gas fires in tight, unoccupied spaces.
Field deployments in industrial energy units demonstrate reduced fire damage and faster recovery compared to cylinder systems.
Final observations
For energy-related fire risks, the N2 Gen by DSPA system surpasses high-pressure cylinder-based alternatives by prioritising safety, simplicity and efficiency.
Its non-pressurised, compact design addresses the sector’s unique challenges – limited space, high reliability demands and cost pressures – while delivering proven nitrogen-based suppression.
As energy infrastructure evolves toward modular and sustainable designs, adopting N2 Gen enables proactive protection, ensuring operational continuity and asset preservation.
Stakeholders in power generation, transmission and storage should evaluate N2 Gen for its transformative potential in fire safety.