We commonly use natural gas for heating in industrial complexes; undetected gas leaks or incomplete combustion could cause an explosive hazard or an influx of carbon monoxide, resulting in loss of life, structure damage, or expensive waste of fuel.
Why do we need a gas detection system for a boiler room?
The boiler room is not frequently occupied; this may lead to the leak remaining undetected.
A continuous gas monitoring and detection system will provide early warning of a gas leak and prevent loss of life and material.
What gases can be found in boiler rooms?
Natural gas
Natural gas is used in the industry for heating, and undetected leaks can be deadly. Nearly half of the natural gas is methane. Since natural gas is lighter than air, it will immediately rise to the ceiling or roof space of the boiler room.
Carbon Monoxide
Carbon monoxide is the result of the incomplete burning of hydrocarbon fuels such as wood products, natural gas, fuel oil, and coal.
For this reason, carbon monoxide and natural gas monitoring are essential for gas detection in boiler rooms.
Components of Boiler room gas detection system
The boiler room gas detection system consists of sensors that are strategically placed to detect natural gas and carbon monoxide, with a controller that will have relays or that can connect to an external system.
Gas sensors
I recommend selecting catalytic bead sensors for boiler room applications. Catalytic bead sensors are less prone to false alarms than solid-state or semi-conductor sensors.
Catalytic bead sensors have a life expectancy of 3 to 5 years, sometimes even more depending on how well you take care of them and environmental factors like temperature and humidity.
Boiler rooms are considered safe areas, i.e., you do not need explosive-proof sensors, but it is recommended to use them and if possible, use class I Div I sensors.
My recommendation for this would be Sensepoint XCD or E3point, both manufactured by Honeywell.
Location of the sensors
Natural gas is lighter than air, which means the gas will concentrate near the roof, so my recommendation would be to place at least one sensor on the roof (typically one foot from the roof), and the rest of the sensors should be located over potential leak areas.
This includes
- The gas burner assembly.
- The gas train assembly.
- The pressure boosters (if boosted).
- The gas shut-up valve.
- The combustion air intake.
- The gas meter.
Depending on the size of the boiler room, the rule of thumb is to install one sensor for each 25 feet of radius.
The controller
It is recommended to have at least one controller in the boiler room; as its name suggests, the controller will be the main brain of the gas detection system. You can set it up to shut down the valves, activate relays, or activate the horn and strobe.
Here are my recommendations when it comes to selecting a controller for the boiler room gas detection system.
Location of the controller
I recommend having a controller outside the boiler room so that people can see what is going on in the boiler room before they enter it.
Compatible with the sensors
I have seen people buy sensors from one manufacturer and the controller from a different one, or the same manufacturer, but they are incompatible.
Make sure the sensors you have can communicate with the controller; if you have 4-20mA sensors, you need a controller that can take 4-20mA input; if the sensors are Modbus, make sure the controller can accept Modbus inputs.
The controller must have relays
Depending on what you want to do, you may need a controller with relays; this can be to shut down a control valve, start or stop a fan, process, etc.
Power Supply
Most controllers run on 24 VDC; make sure that you have the power supply that can help the sensors and the controller.
Visible Display
I recommend a controller that has a visible display so that people can be able to see the reading in real-time.
Integration Options
Depending on whether the boiler room gas detection system is stand-alone or is integrated with a larger system.
If you are going to connect it to a building management system (BMS), probably you need a controller that has BACnet (Building Automation Control Network) protocol as an output.
FAQ: Gas Detection System For Boiler Rooms
What detector do you need for a boiler room?
You need two types of detectors, for carbon monoxide and flammable gases (LEL).
How many sensors do I need for a boiler room?
It depends on how many potential leaks there are; I recommend one per potential leak. Make sure the sensors are placed near the potential leak.
Is a carbon monoxide detector required in a boiler room?
Each boiler room containing one or more boilers from which carbon monoxide can be produced shall be equipped with a carbon monoxide detector with a manual reset.
Key takeaways: Gas Detection System For Boiler Rooms
Most industries, including boiler rooms, use natural gas for heating; this poses the danger of explosion due to the natural gas leak, or the unburned gases can turn into carbon monoxide.
To design a gas detection system for boiler rooms, you need to consider sensors that will detect methane (LEL sensors) and carbon monoxide.
I recommend using electrochemical sensors because they have an expected life of 3 to 5 years and produce fewer false alarms.
You need to place the sensors near the position where there is more possibility of a leak and the controller outside the boiler room where it is visible so that people can see the reading before they enter the boiler room.
