Water leakage detection is sometimes overlooked in favour of temperature and humidity monitoring. In any IT environment such as a computer room, server room or datacentre, water, or the build-up of any other type of liquid or large amounts of condensation can lead to disastrous consequences including short-circuits, equipment damage and corrosion and operational downtime. Water leakage can also present a fire risk.
Any server environment can have one or more potential sources of water and other liquids. Typical sources include:
A poorly maintained air conditioner can be prime source of water leakage through a build-up of condensation. Gravity simply ensures this drops to the floor where it pools or onto server racks and cabinets from which it can then leak into areas housing the servers, storage, and network devices. As server rack densities rise and server compute capacities rise, so do the power and cooling demands. This is one of the reasons for the rise of liquid cooling within server rooms and datacentres and the associated concern with water leakage detection.
Other potential leaks and sources include roofs and windows, underfloor seepage from polling sealed foundations, battery acid leaks (especially wet cells) and even diesel from nearby standby power generators.
When designing a server room or datacentre facility, one of the key decisions is how to reduce the risks of condensation build up and water leaks and provide sufficient monitoring and protection. In terms of planning the following checklist can be used to assess potential risks and how to remove them.
A water leakage detection checklist can be used as part of a Risk Assessment and Method Statement (RAMS) document and incorporated into an overall server room or data centre design project. A comprehensive approach is required to review the entire IT facility including support, storage, and workshop type areas.
The most obvious sources are those that use chilled water or can lead to water build-up and condensate, including air conditioning and cooling systems. By their nature, these systems are typically installed near to IT servers, racks and cabinets and can present the greatest risks. Other, less obvious sources including critical power systems such as diesel power generators and UPS lead acid batteries, HVAC and piping systems within the building and the building location and environment itself.
Whilst water presents the most obvious liquid to detect for, there are others. The cooling system could use an ethanol-based coolant. Most UPS batteries tend to use a GEL-type electrolyte, but large UPS batteries may be based on wet-cell technology with a liquid (hydrochloric-acid) electrolyte. Other potential liquids include the local storage of caustic chemicals in an industrial environment and diesel fuel tanks. For these types of liquid specialist sensors and cables can be installed.
For some areas of the installation it may be possible to use point-sensors to detect a leakage. A typical example includes an air conditioner and/or drip trays and drainage. These types of sensors detect a single point of liquid build-up. It is more common to use apply cable sensors that can detect liquid along the length of the cable installed. These cables can run up to 100m in length and are useful for use on or under flat surfaces (raise access floors and suspended ceilings) and along pipe runs.
The action(s) to be take can depend on the type of liquid detected. A chilled-water leak could require a complete shutdown of the system with automatic valves closing. Condensation build-up in an underfloor or overhead area may only require a local investigation and repair with no downtime.
Having identified which systems within a server room or datacentre could present a water or other type of liquid spillage or leak, it is important to ensure that there is effective maintenance in place for them. An annual preventative maintenance visit helps to ensure any critical infrastructure system is operational effective. Filters can be cleaned or replaced, connections checked for torque ratings, cables for ‘wear and tear’ and alarm logs checked. These checks are just some of the functions carried out by an installation engineer and there may be more given the type of equipment being inspected and its age.
In addition, having identified a potential risk, changes to the system design or location may take place to ensure that the risk is reduced and mitigated for. Drip trays for example can be used to ‘catch’ potential spillage and critical IT equipment moved away from overhead problem areas. As important is the need to check that final monitoring system is operating as it should be in terms of sensor operation and alarm distribution.
The most common way to monitor for leakage detection in a server room or datacentre is to install an environment monitoring device. This could be a dedicated one for water leak monitoring or a centralised leakage protection system that can monitor several sensor inputs and zones including water leakage, ambient temperature, humidity, smoke, fire, power, and motion.
Whichever is installed, a key planning aspect is how alarms are to be alerted to a distribution list. Circulation can be via TCP/IP, email, SMS, and SNMP and include local LAN as well as web-based portal monitoring as well as reporting into a centralised building management system (BMS).
Single leakage detection cables come in varying lengths from 2m to 50m or more and can be extended up to 100m or more. A typical cable can detect water or ethylene glycol. Once the cable has detected a leakage it can typically be washed in clean water and/or dried for later reuse. Specialist detection cables may be required for diesel, acid, and other caustic liquids.
Air conditioners and chilled-water cooling systems provide the greatest potential for condensation build-up and leakage in a server room environment. They are not the only source and the risks presented can only be mitigated for by following a comprehensive review, checklist, and risk assessment. Water leakage detection is often overlooked in favour of temperature and humidity monitoring but can pose as great a risk to operational downtime. For security and resilience, a multi-faceted environment monitoring system is recommended that can monitor for temperature, humidity, and leakage.
It is difficult to predict the British weather at the best of times. Over the last year we have seen extreme changes within days, from high temperature heat waves to torrential downpours. For anyone running and IT facilities, these weather patterns create additional demands on local cooling, temperature and humidity level management systems.