Heating and Ventilating

Innovation in wireless sensor technology boosts sustainability, helps create a more efficient control system and saves installation time and cost, says Alan Braybrook
The European Union has set carbon emission reduction targets of 20 per cent by 2020 and 80 per cent by 2050. However, change may be on the way. The coalition is keen for the EU to increase the 2020 target to 30 per cent 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 per cent target in 2050.

The Chartered Institute of Building (CIOB) believes that around 47 per cent 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 per cent 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 maximise sustainability, minimise fuel consumption and cut energy costs.

As only 2 per cent 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.

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 and 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 re-location 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 and routers, and software, this product range is built on a robust 2.4 GHz, 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 also been addressed through a proprietary algorithm which continually adapts to site conditions.

By eliminating the need for structural cabling during sensor installation for an 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.

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.

Driver offers seamless integration

The RF-RXS SonNet Niagara serial driver is designed to offer 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.

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 is claimed to ensure 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 Niagara framework.

The author is sales and marketing director at Sontay