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Overview
Natural gas leaks in residential and light commercial premises are a leading cause of gas-related accidents — and the majority occur at points that are invisible to occupants: pipe joints behind walls, hose connections at appliances, corroded fittings beneath counters. By the time a gas leak becomes detectable by smell alone, methane concentration may already be approaching a level that presents a genuine ignition risk. The challenge for building managers, facilities teams, and safety-conscious residential properties is providing reliable, continuous gas leak detection at a concentration level that triggers a warning well before that threshold is reached.
The BH-H5 Household Gas Alarm addresses that directly. It is a mains-powered fixed gas alarm designed for residential and light commercial installation, detecting methane (CH4) at an alarm threshold of 10% LEL — a concentration that triggers the alarm at roughly one-tenth of the lower explosive limit, giving occupants and building managers significant warning time before the gas reaches a dangerous level. It requires no batteries, no recharging, and no replacement power source — simply wired into the AC supply and operational from that point forward.
What differentiates the BH-H5 from basic domestic gas alarms in this category is the inclusion of two relay outputs capable of controlling an AC220V solenoid valve. This means the alarm can be integrated with an automatic gas shutoff valve — so when a leak is detected, the gas supply is physically cut at the source without requiring any human intervention. For property managers, building safety officers, and landlords with gas safety obligations, that automatic shutoff capability transforms the BH-H5 from a warning device into an active gas safety control measure.
Key Features
10% LEL Methane Detection — Early Warning Threshold
The BH-H5 triggers its alarm at 10% LEL — 10% of the lower explosive limit for methane. The LEL for methane is approximately 5% volume in air, meaning the alarm activates at around 0.5% volume concentration — well before the gas reaches a flammable range. This early warning threshold gives occupants and building managers time to ventilate, evacuate, and shut off the gas supply before the situation becomes critical. Detectors that alarm only at higher LEL thresholds provide less margin for response.
Dual Relay Output — AC220V Solenoid Valve Control
The BH-H5 includes two relay outputs that can directly control an AC220V solenoid valve on the gas supply line. When the alarm triggers, the relay output can automatically close the solenoid valve — cutting the gas supply at the source without any human action required. For properties where occupants may be asleep, evacuated, or otherwise unable to respond immediately, automatic gas shutoff is a safety measure that passive alarm-only detectors cannot provide. Two relay outputs allow connection to both a solenoid valve and a secondary alarm or notification device simultaneously.
AC Mains Power Supply — No Battery Management
The BH-H5 is powered directly from AC 90–264V mains supply with an overall power consumption of less than 2W. There are no batteries to replace, no charging cycles to manage, and no risk of the device failing due to battery depletion. For fixed installation in residential or commercial premises, mains-powered operation is the appropriate power approach — continuous, reliable, and requiring no maintenance intervention for the power supply throughout the device’s operational life.
5-Year Sensor Life
The methane sensor is rated for a 5-year operational lifespan under normal usage conditions. For building managers and property companies responsible for gas safety across a portfolio of premises, a 5-year sensor life provides a defined and manageable replacement schedule. Rather than replacing detectors on an ad-hoc basis driven by unknown sensor degradation, a 5-year cycle allows planned sensor replacement as part of a structured gas safety maintenance programme.
Natural Diffusion Sampling — Passive Continuous Monitoring
The BH-H5 uses natural diffusion sampling — drawing the ambient atmosphere directly to the sensor without a pump or fan mechanism. This passive approach is the appropriate detection method for fixed residential and light commercial installation: it requires no moving parts to maintain, consumes minimal power, and provides continuous monitoring of the ambient atmosphere throughout the sensor’s operational life without any active maintenance requirement.
Sound and Light Alarm — ≥70dB Audible Alert
When gas is detected at or above the 10% LEL threshold, the BH-H5 triggers a combined sound alarm of 70dB or greater and a visual light alarm simultaneously. The 70dB minimum sound level is sufficient to alert occupants in adjacent rooms and to wake sleeping occupants — important for a gas safety device in residential premises where the most dangerous leak scenarios often occur at night. The visual light alarm provides additional indication for occupants with hearing impairment or in high-ambient-noise environments.
3-Minute Warm-Up Time — Fast to Operational Status
The BH-H5 reaches full operational status within 3 minutes of being powered on. For a mains-powered fixed installation this is primarily relevant during initial installation and after any power interruption — the device returns to active monitoring quickly without an extended stabilisation period that could create a monitoring gap after a power cut.
Technical Specifications
Model: BH-H5
Target Gas: Methane (CH4) — Natural Gas
Alarm Threshold: 10% LEL
Power Supply: AC 90–264V (mains powered)
Power Consumption: < 2W
Relay Output: 2 relay outputs — AC220V solenoid valve control
Alarm Method: Sound (≥70dB) and Light alarm
Response Time: T90 ≤ 30 seconds
Warm-Up Time: 3 minutes
Sensor Life: 5 years (subject to usage environment)
Sampling Method: Natural diffusion
Working Temperature: 0°C to 55°C
Humidity Range: < 95% RH (non-condensing)
Benefits
Automatic gas shutoff without human intervention. The relay output connection to a solenoid valve means that when a leak is detected, the gas supply is physically cut at the source — automatically, immediately, and regardless of whether anyone is present or awake. For residential properties, hotels, and commercial kitchens where unattended gas leaks are a realistic scenario, this is the safety outcome that a passive alarm-only detector cannot provide.
Early warning at 10% LEL gives meaningful response time. Triggering at 10% of the lower explosive limit means occupants and building managers have significant time to respond — ventilate the space, evacuate if necessary, and shut off the supply — before gas concentrations approach the flammable range. This margin is what makes the difference between a managed gas leak incident and an emergency.
No ongoing power management required. Mains-powered operation with under 2W consumption means the BH-H5 is always on, always monitoring, and never requires battery replacement or charging attention. For property managers responsible for gas safety across multiple premises, removing battery management from the maintenance schedule is a meaningful operational simplification.
Planned 5-year sensor replacement cycle. A defined 5-year sensor life allows gas safety maintenance to be scheduled and budgeted as a routine programme activity — not triggered by unknown device failure. For landlords and property companies with formal gas safety obligations, planned sensor replacement supports a more defensible and auditable safety management record.
Dual relay output supports system integration. Two relay outputs allow simultaneous connection to a solenoid shutoff valve and a secondary alarm output — a remote panel indicator, a building management system input, or an external siren — without requiring additional interface equipment. This flexibility supports integration into existing building safety systems without significant additional hardware cost.
Who It’s For
The Property Manager or Landlord with Gas Safety Obligations
You’re responsible for the gas safety of residential tenancies or commercial leased premises. Your gas safety programme requires annual gas safety checks, and increasingly, continuous gas detection as part of a responsible safety provision. The BH-H5’s 5-year sensor life gives you a clear replacement schedule to build into your maintenance programme, and the relay output solenoid valve connection gives you an automatic shutoff capability that significantly reduces the risk exposure of an undetected leak in an unoccupied or sleeping property.
The Building Services Manager at a Hotel, Serviced Apartment, or Commercial Kitchen Facility
You manage gas safety across a multi-unit property where cooking gas, hot water, and heating systems create continuous low-level gas risk. You need fixed gas detection in kitchen areas, plant rooms, and gas meter rooms that provides early warning and — critically — can automatically shut off the gas supply if a significant leak is detected outside operational hours. The BH-H5’s relay output solenoid valve control and mains-powered continuous operation address both requirements without requiring ongoing battery management across a distributed installation.
The Gas Safety Installation Contractor
You install gas detection and shutoff systems across residential and commercial premises as part of new build, retrofit, and gas safety upgrade projects. You need a fixed gas alarm that is straightforward to wire into the AC supply, connects directly to a standard AC220V solenoid valve via relay output, and provides a documented 5-year sensor life that you can communicate to the building owner as part of the installation handover. The BH-H5 meets all three of those specification requirements in a single compact wall-mounted unit.
Possible Applications
- Residential properties and apartments — Fixed natural gas leak detection in kitchens, utility rooms, and areas adjacent to gas appliances with automatic shutoff capability
- Hotels and serviced apartments — Gas safety monitoring in guest room kitchenettes, central kitchen areas, and boiler plant rooms
- Commercial kitchens and food service premises — Continuous methane monitoring at cooking equipment connections, gas manifolds, and supply pipework with solenoid valve shutoff
- Retail and commercial properties with gas supply — Gas safety monitoring in back-of-house areas, plant rooms, and gas meter rooms in commercial premises
- Care homes and assisted living facilities — Gas leak detection in communal kitchens and individual units where occupants may have limited capacity to respond to a gas emergency
- Laboratories with gas supply — Fixed methane monitoring at natural gas supply connections to laboratory equipment and Bunsen burner manifolds
- Facilities management — multi-site property portfolios — Standardised gas alarm installation across residential or commercial property portfolios with defined 5-year sensor replacement cycles
- New build and retrofit gas safety upgrades — Integration into new build gas installations and retrofit safety upgrades as part of comprehensive gas safety system design
Trust and Certifications
10% LEL Alarm Threshold — Industry Standard Early Warning Level
The 10% LEL alarm threshold is consistent with recognised gas detection standards for residential and light commercial fixed gas alarms. Setting the alarm at 10% LEL provides a clear safety margin below the flammable range while minimising nuisance alarms from very low background concentrations. For building safety officers and gas safety installers specifying fixed detection systems, the 10% LEL threshold is the established benchmark for residential natural gas alarm applications.
5-Year Sensor Life — Manufacturer Specified
The 5-year sensor life is a manufacturer-specified performance parameter that allows maintenance planning, budget forecasting, and compliance programme management on a defined cycle. For property managers and facilities teams with formal gas safety management obligations, a clearly specified sensor life supports a more auditable and defensible maintenance record than detectors with unspecified or highly variable sensor lifespans.
Dual Relay Output — Verified Solenoid Valve Compatibility
The two relay outputs are rated for AC220V solenoid valve control — the standard voltage for gas shutoff solenoid valves used in residential and commercial gas safety systems. This verified compatibility with standard solenoid valve technology allows direct integration without additional interface equipment or voltage conversion.
Authorised by Alright Engineering Solutions
The BH-H5 is supplied through Alright Engineering Solutions Pte. Ltd., an authorised distributor of personal and portable gas detection equipment in Singapore. Alright Engineering Solutions provides local procurement support, installation guidance, and after-sales assistance for the Singapore and regional market.
Accessories and Variants
AC220V Solenoid Gas Shutoff Valve
A compatible AC220V solenoid valve installed on the gas supply line connects to the BH-H5 relay output to provide automatic gas shutoff on alarm. Available separately — contact Alright Engineering Solutions for solenoid valve options compatible with your gas supply pipe size and pressure specification.
Secondary Alarm Output Device
The second relay output can be connected to a remote alarm panel indicator, external siren, or building management system input — extending the alarm notification beyond the immediate installation area to a central monitoring point or security station.
Wall Mounting Hardware (Included)
The BH-H5 is supplied with wall mounting hardware for standard installation. Mounting position should follow the manufacturer’s installation guidance for methane (lighter than air) — typically above head height near gas appliances and supply connections.
Related Products from Alright Engineering Solutions
BELLMINI Single Gas Detectors — Personal portable gas monitors for CO, H2S, O2, and industrial gas hazards
BT-S100 Portable Gas Leakage Detector — Handheld probe detector for gas leak location surveys
BH-90E Portable Gas Leakage Detector — Handheld combustible gas and refrigerant leak detector with flexible probe
Get in Touch
If fixed natural gas detection with automatic shutoff capability is part of your property’s gas safety requirements — whether for a single residential installation, a multi-unit property portfolio, or a commercial kitchen or hospitality facility — the BH-H5 is worth discussing with our team.
Contact Alright Engineering Solutions to request a formal quote, discuss solenoid valve compatibility for your installation, or get guidance on BH-H5 placement and wiring for your specific premises.
📍 3791 Jalan Bukit Merah #06-01, E-Centre @ Redhill, Singapore 159471
