Water Leaks

The 3 Types of Water Leak Detectors a Smart Building Needs

Smart buildings need 3 types of water leak detectors. Find out what these are, and how they can help you protect your buildings.

The cost of water damage to our homes and businesses is immense. Flooding, broken pipes and minor, hidden leaks are the leading cause of commercial property insurance claims. Allianz Global Corporate & Security, in an analysis of nearly half a million claims between 2013 and 2018 from over 200 countries and territories, found that water damage accounted for the third-highest number of insurance claims for global business.

It’s a serious pain point not just for commercial building owners, but also for the insurers that have to underwrite them. In the future, costs will always rise.

Given this, insurers everywhere are recommending, amongst other things, leak detection monitoring technology.

Water leak solutions usually have several components, including sensors, alarms, monitoring platforms, and automatic shut-off valves. The main idea is to use these tools to detect water leaks as early as possible to minimize damage.

Whether you're trying to protect a school or retail store, knowing how each sensor works and its best features is important before purchasing. We’re going to focus on smart water leak sensors, as IoT devices are becoming the standard for remote monitoring.

There are three main types of sensor-based water leak detection that a commercial building uses to protect from water leaks: flood sensors, printed & bcale sensors, and in-line sensors.

Below, we’ll cover how each works and how they can protect your building from water.

Flood sensors

Flood sensors, also known as spot leak sensors, are the most popular type of water leak sensor. They're usually made as small, palm-sized pucks or blocks, with one or more probes attached. Flood sensors are mostly installed next to hot water tanks, dishwashers, or washing machines.

Flood sensors have the benefits of being easy to deploy and easy to power with standard-size household batteries. In addition, when the probes touch water, the device has a loud alarm to alert you to a possible leak. In more sophisticated systems, visual or auditory alarms are replaced with wireless communication methods such as Wi-Fi, Bluetooth or LoRaWAN which alert facilities management directly.

The biggest downside to these is that you must place them strategically so any water leaking will reach their probes. This may mean that a leak has already caused significant water damage before reaching the sensing probe. They also are generally used in open areas and on hard surfaces, meaning they won’t detect leaks in spaces with insulation or materials that can absorb a lot of water, like drywall.

Additionally, flood sensors are usually only made with hard casings and only work on flat surfaces, making them ineffective in tight or angled spaces.

Examples of makers of these kinds of sensors include Flo, Phyn, and Monnit.

Sensor on the floor


Printed sensors & sensor cables

Where a flood sensor will only activate when water is already pouring into a space, printed sensors and sensing cables are designed to detect any moisture as early as possible.
Firstly, water sensing cables come in a variety of lengths, but all work with the same mechanism that depends on its cable becoming saturated. These cables can span across the edges of a room or full areas so can protect buildings with large rooms. Their ability to cover rooms comes with the largest price tag, however, at around five times the cost of a typical flood sensor.

Printed Sensors on the other hand are much more scalable economically as designs are based on an affordable polymer substrate. Also where cable sensors can detect across their long, thin lengths, printed sensors have a much higher coverage area whilst being flush to a surface. Therefore, in the case of a roof, printed sensors can be installed flat between waterproofing membranes and facility managers know exactly where a leak is due to the full coverage.

Although there are fewer printed sensor solutions, the Severn WLD stands out with performance, installation and cost. Its printed design allows as little as 2 drops of water to be detected and its distinct 12 electrodes mean that the severity of the leak can be measured.

Aside from LAIIER, other makers of printed sensors and sensor cables include Alliot, AKCP, and ALTA.

In-line sensors

The last kind of sensor is very different from the first two. Where flood, cable and printed sensors require direct contact with water leaks, in-line sensors monitor flow rate and water pressure inside water inlet pipes to deduce if there is a water leak happening.
In-line sensors are therefore installed within a water network which is similar to how a water meter works. In-line sensors can be divided into invasive and non-invasive types depending on whether they require pipe cutting or not respectively.

Invasive flow meters measure the rate at which water travels through a pipeline via a rotating fan. The higher the flow rate of water, the faster the blades spin, letting the device know the water usage behavior. In the instance where water is used for prolonged amounts of time, this can imply the presence of a leak.

Non-invasive in-line sensors, however, do not need to interrupt the water network and can be clipped onto the pipe. Most non-invasive solutions have ultrasonic technology to track the water flow through pipes. If a water leak is present, small bubbles emit particular sound waves, which can be flagged as a leak.

In more advanced in-line sensor technology, machine learning capabilities have been supported. Here recorded usage patterns can be tracked over time detecting abnormal behavior much easier.

Like the other sensors, these can be connected to the cloud, so these devices can send push notifications automatically.

In-line sensors have the advantage of being installed within your plumbing network so leaks anywhere around the property can be detected. Many models can also automatically shut off the water supply if a critical threshold is reached.

The one major disadvantage is that an in-line sensor cannot tell where a leak is happening. They also don’t help sense leaks outside the building, such as from weather or external flooding.

Furthermore, despite being able to detect very small deviations, in-line sensors are also notorious for false positives. The impacts of an expansion tank in a hot water system can be detected as a leak which can flag up a false alarm. Small leaks on the other hand may not be detected at all.

Overall, in-line sensors may not be suitable for situations that need high reliability, such as in critical commercial properties.

Examples of makers of flowmeter sensors include Grohe, ABB, and Flume.

Flow meter

The right kind of sensor can make facilities management work much easier

Each sensor type has its pros and cons, but you must also understand what your building type requires before deciding on the best sensor. For low budgets, flood sensors may be the best suited if accuracy or reliability is not important. For more critical scenarios with tight spaces, printed sensors are much more appropriate.

LAIIER’s Severn WLD sensor, for example, is a thin, flexible sensor that can be applied like tape in small and wide covering areas. The unique printed design means it can detect as little as 0.1 ml of water whilst also giving more informed insights to the size and growth of a leak. These proactive insights can be communicated swiftly to facility managers through our LAIIER Cloud platform. To learn more about how the Severn WLD can be used, check out our use cases.

Want a more in-depth comparison of the latest water leak sensors? Download our new whitepaper to read more.

LAIIER sensor under a water tank

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