Sensors for early maintenance alert

This Issue This is a part of the Innovation and the future feature

By - , Build 109

Are we moving towards ‘dashboard’ displays in our buildings where sensor systems will warn of degradation in building materials?

Wiring for the sensors installed in the weathertightness experimental building.
In the future, buildings may have sensor displays like this, which are accessible via the internet.
In the future, buildings may have sensor displays like this, which are accessible via the internet.

Drivers are familiar with the information (and warnings) displayed on their car dashboard, so why not have a similar dashboards display to ‘drive’ and monitor buildings? Currently, the implementation of this type of technology in residential properties is restricted to those interested enough to build their own sensor and interface systems, but BRANZ hopes its current research will bring such technology into mainstream use.

Sensors to ID material degradation

BRANZ is exploring the possibility of using sensors and indicators to identify early degradation of building materials, before any consequential deterioration occurs. Such techniques are well developed in the aerospace, automotive and shipbuilding spheres, but they haven’t been widely adopted in the construction industry, with the exception of some pilot projects to monitor infrastructure such as bridges.

Building monitoring systems

The building monitoring systems that already exist clearly demonstrate the potential to monitor a building’s temperature, indoor humidity, heating/cooling system operation and energy consumption. Some systems publish the readings to the internet, allowing up-to-the-minute access from any location. There is evidence that owners spot and remedy problems quickly using these systems.

In the United Kingdom, the development of dashboard-like smart meters for electricity and gas offer consumers more control over their energy consumption, while reducing the cost of manual meter readings.

In the longer term, it is envisaged that these technologies will develop to give residents a greater overview of the running costs, performance and maintenance needs of their properties. An added benefit would be the reduced cost and complexity of remedial work when problems arise. By detecting problems earlier, the loss of amenity for repairs should also be minimised.

Simple sensors used by BRANZ

BRANZ has already successfully developed and used simple sensor technology. For example, simple humidity, temperature and moisture pin sensors were used to detect and track moisture movement in the weathertightness house. The results have been useful to the New Zealand building industry, and the research programme is internationally recognised.

In the mid-1990s, a network of temperature and humidity probes was installed in the BRANZ laboratories. These probes were used for computer logging of the lab conditions.

BRANZ has also completed preliminary work showing the feasibility of developing simple ‘tell-tale’ sensors for environmental exposure (see Build 102, October/November 2007, pages 70–71). An indication of UV exposure is believed to be the most crucial requirement for synthetic building wrap materials, so markings to indicate excessive exposure to solar radiation were examined. Several printing ink types were identified and were tested by applying them to a representative sample of synthetic building wraps. The results indicated that sensitive indications of solar exposures were possible in the timeframe required. These results were reported in BRANZ study report SR178.

Corrosion and moisture sensors

A review of the literature on corrosion sensing and sensors has already been completed. Based on this review, and considering the conditions that exist within a building, BRANZ believes that there is considerable potential to develop probes that could gather reliable results in different environments.

BRANZ’s materials science expertise is also being applied to develop other sensor technologies, mainly focusing on moisture detection. It is hoped that these new moisture sensors will be capable of detecting unwanted moisture in specific material types and in inaccessible areas of the building structure. They will mimic typical construction materials to give a realistic measure of what is going on within the building envelope and give an early warning when problems develop.

Wiring for the sensors installed in the weathertightness experimental building.

Demonstrating the technology

In parallel, the research will explore the potential of using ‘real time’ sensor outputs to produce a building dashboard incorporating web-based building monitoring. A publicly accessible web portal will show how simple sensor data could allow the remote identification of problems within a building in a timely fashion.

To do this, commercially available sensors will be installed in one of the experimental buildings at BRANZ’s Judgeford site. These installations will copy how sensors have been used in existing research programmes, as well as installing sensors in a way that could be replicated in residential properties. Outputs from these sensors will be linked to the BRANZ local area network and uploaded to the internet.

To demonstrate how the responses of the sensors could be used to quickly diagnose problems inside the building structure, leaks will be introduced within some areas. It is expected that the readings from the affected areas will be clearly different from the normal readings. As a result, investigation and repair could be quickly undertaken.

For more

To download BRANZ study report SR178, go to the BRANZ Shop at www.branz.co.nz.

Download the PDF

More articles about these topics

Articles are correct at the time of publication but may have since become outdated.

Wiring for the sensors installed in the weathertightness experimental building.
In the future, buildings may have sensor displays like this, which are accessible via the internet.

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