Join the wireless revolution

Ground breaking innovation in wireless sensor technology helps create a more efficient control system and saves installation time and cost in new controls projects as well as opening up new retrofit opportunities for the building services sector as Alan Braybrook, Sales and Marketing Director at Sontay, explains.

The European Union has set carbon emission reduction targets of 20% by 2020 and 80% by 2050. However, change may be on the way. The coalition is keen for the EU to increase the 2020 target to 30% with other EU countries also agreeing an increase in the targets would benefit Europe’s long-term low carbon aim. By increasing the targets now, it means we are more likely to reach the 80% target in 2050.

The Chartered Institute of Building (CIOB) believes that around 47% of the UK’s carbon emissions come from the construction industry and the built environment. There are currently 1.8 million non-domestic buildings in the UK and they generate around 18% of the country’s total CO2 emissions. In the UK we already have an ageing building stock with three-quarters of commercial buildings being more than 25 years old and nearly one-third being over 70 years old. It is also thought that a significant number of buildings, which will be around in 2050 have already been built meaning that refurbishment is going to be the best way to cut carbon emissions.   

With new targets on the agenda and an increasingly ageing building stock it is now more important than ever for the building services sector to minimise fuel consumption and cut energy costs.

As only 2% of the UK’s existing buildings are less than five years old, there is a massive opportunity for energy savings through controls installation. However, the cost and complexity of installation can be seen as a barrier to wider adoption. Retrofitting a wired HVAC control system is by necessity a disruptive and expensive business.

Count the cost

In new buildings, project timescales for controls installation can often be extremely pressurised. With traditional wired systems, this can impact adversely upon the ease, efficiency, time and labour costs associated with the controls installation process.

And, once the controls have been wired into place, what happens when the internal layout changes because of office churn? Sensors must invariably be moved to accommodate the new requirements. In many cases, the cost and disruption that this process involves means that sensor relocation just does not happen. As a result, the performance of the control system, and efficiency of the building services themselves risk being compromised.

Thanks to new wireless sensor technology it doesn’t have to be this way anymore. For example, our new SonNet range of wireless temperature and relative humidity sensors are designed to provide accurate measurement of temperature and relative humidity within a building and then communicate these readings reliably to its control system.

Comprising battery powered sensor nodes together with permanently powered network receivers, routers and software, this innovative product range is built on a robust 2.4GHz, 802.15.4 self-healing, wireless tree topology.

This topology is significant because it eliminates concerns with reception and reliability often associated with existing ‘point-to-point’ wireless systems. If a sensor detects a problem with the signal, it will automatically re-route to find the strongest available path to the receiver. Interference with other radio devices in the same frequency spectrum has also been addressed through a proprietary algorithm which continually adapts to site conditions.

Reduce installation time

By eliminating the need for structural cabling during sensor installation for a HVAC control system, such devices can greatly reduce engineering time and installed project cost. This enables faster and easier installation on new buildings and also opens up the opportunity for control specialists to retrofit energy efficient HVAC controls into existing commercial and public buildings.

For ease of commissioning, a dedicated site survey kit allows engineers to map any building for suitability prior to carrying out site installation. It helps them analyse transmission paths and signal strengths between proposed sensor locations and receivers to ensure that a sound communication path will be achievable when site installation is completed.

Using this type of wireless technology will also bring building owners and facilities managers enhanced site flexibility, allowing for building layouts to be changed on a regular basis without the need to re-wire sensor configurations accordingly.

The ability to integrate the whole building management system will also provide significant benefits, including energy and maintenance cost reductions. Being able to monitor the HVAC system through one framework is more likely to provide a reliable set of readings and give end-users a simpler way to monitor their building. To this end, we have introduced the RF-RXS SonNet Niagara serial driver which offers seamless integration with the Tridium range of JACE controllers.  This opens up the use of SonNet to many other BMS protocols such as BACnet, LonTalk and Modbus.

Open framework

Tridium’s NiagaraAX is an open, Java-based framework which integrates diverse building services systems, control devices and communications standards, including LONWORKS, BACnet, Modbus and others into an interoperable, web-enabled application environment. The new driver ensures Sontay’s RF-RXS receivers serve up a Tridium compatible web interface where SonNet wireless sensors are used on a project. This allows engineers to gather measurement data from the sensors and also perform radio network management services, such as, auto-commissioning and setting device configuration parameters as part of a building’s Tridium NiagaraAX framework.

School buildings are a good example of where installing wireless sensors can save time, money and energy. Guidance on CO2 levels was an integral part of the original Building Schools for the Future scheme, enshrined in the regulatory framework of Building Bulletin 101. This specified limiting CO2 levels within teaching and learning spaces to 1500ppm in recognition of the proven link that exists between indoor air quality and its impact on the academic performance of children. This places a large emphasis on ventilation but without an appropriate building control system there is no way of measuring the levels of CO2. 

The problem with many existing school buildings is that fresh air supply rates per person are often well below what should be the recommended level of between 10-12l/s, therefore CO2 concentrations are well above the recommended figure. This not only impacts upon the learning abilities of pupils but it also leads to adverse health effects.

The key is accurate air quality measurement, and here innovation in wireless technology helps make life more comfortable for specifiers as well as for school occupants. Installation is quicker and easier than with a wired system allowing for less disruption to the school and cost savings. The accurate measurement the wireless system provides also ensures the school is saving on its energy usage.    

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