Safehouse Technology Ltd | Legionella Deection

Legionella management and control

The control of legionella applies to all non-domestic building in the UK, and it is a legal requirement for any employer, or someone in control of premises to undertake this role.


One of the measures required, as outlined in the Health and Safety Executive (HSE) Approved Code of Practice (ACOP) L8, is to measure and monitor the temperature of the hot and cold (H&C) water system installed in a building. Currently water temperature at various outlets is being measured and logged manually once a month or less. This practice is very time consuming and labour intensive, and thus expensive.
















BRE and Skanska has shown that water pipe surface temperature is a reliable indication of the actual water temperature, and the change in temperature (because of the flow of H&C water) can be readily detected by an on-pipe temperature sensor.


The system developed by Safehouse for BRE, Selex  and Skanska comprises of wireless temperature sensors attached to water pipes at locations close to individual outlets. Temperature data can be monitored and logged remotely and continuously through a wireless connection without any human intervention. Wireless data transmission will be based on an intelligent strategy to extend the life of wireless sensor batteries as far as possible. The system operates in a way that is in line with the HSE ACOP L8.


The system developed provides significant benefits over traditional control, by reducing human intervention and error, providing continuous measurements rather than one-off snapshot, coverage of all outlets in a building rather than selected ones (sentinel) and Ability to identify water outlet that is not being used regularly (i.e. formation of a potential dead leg)

This capability is totally non-intrusive, and is suitable for application in all non-domestic buildings around the world, either for new build or retrofit.


A simple illustration on how the system works is shown in Figure  below.

The Safehouse hot and cold water temperature monitoring system

Figure 1. Simple illustration  of the Safehouse H&C water temperature monitoring system

Key features of the LIDs system and functional blocks

The current aggregator used for the initial pilot uses a SIM.  The new version of the aggregator is LORA enabled.  


Key features of Safehouse Legionella monitoring system

  • Modular scalable architecture.
  • Wireless battery powered Bluetooth Low Energy (BLE) pipe sensors supporting 2 taps.

  • Wireless mains powered GSM unit monitoring 8 pipe sensors.

  • Temperature monitoring of 2 pipes and ambient temperature for each sensor unit.

  • Pipe sensors running BRE L8 detection algorithm on 2 pipes.

  • Parameters dynamically configurable.

  • Installed as independently reporting clusters.

  • Easy to install and pre site survey.

  • Battery operated, ultra low power technology.

  • 3-5 year operating life as standard, replaceable batteries.

  • Optional 5-7 year version, sealed, use once unit.

  • Figure 3 shows diagram of LIDs system and Figure 4 shows actual LIDS hardware developed and used for the trials


LIDs functional block

  • Pipe Temperature Sensor (PTS)

    • Monitor the pipe and ambient temperature.

    • Send alert and other data to DI unit via BLE communication.

  • Data Integrator (DI)

    • Collect data from up 8 PTS units.

    • Communicate with the CSD via the mobile telephone network or other communication routes (WiFi).

    • Future version of aggregator will be LORA enabled, which will remove the cost of needing a WiFi infrastructure and SIMs


  • Central Server Database (CSD)

    • Collect data from all systems in the field.

    • Send alerts to designated users.

    • Provide data on individual monitored  taps.

  • Data access device (PC, tablet or mobile phone)

    • Receives data for CSD.

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