Innovation in wireless sensor technology can save installation time and reduce costs in new controls projects as well as opening up new retrofit opportunities for the building services sector, says Alan Braybrook.
The building services sector and its clients are under intense pressure to save energy and reduce carbon emissions from new and existing buildings.

Government legislation and incentives are driving through changes in building practices and technologies to ensure that the UK meets its 34 per cent emissions cut on 1990 levels by 2020 which is required under the Kyoto Agreement.

New homes and new schools face a 2016 deadline, public sector non-dwellings are required to become zero carbon by 2018 and other non-dwellings, such as offices, hotels, etc, will need to comply by 2019.

With energy costs rising, it's clear too that financial pressures are playing a part in greening our building stock. It's self-evident that a more fuel efficient solution will help reduce running costs for building owners and their occupiers in new build and refurbishment projects.

Here legislation too is playing its part with the future recasting of the Energy Performance in Buildings Directive likely to extend the burden of requirements on building owners. For example, these will demand that the energy performance of existing buildings of any size which undergo major renovations will need to be upgraded in order to meet minimum requirements. Currently, there is a threshold of 1,000 sq m.

At the same time, DECC is encouraging organisations to measure and report their carbon emissions as well as set targets to reduce them. The Government believes that improvements here will help contribute to a reduction in fuel usage and carbon emissions. Soon after coming to power, the Prime Minister announced that, in its bid to be the greenest government ever and cut carbon emissions by 10 per cent within 12 months, real time reporting of energy efficiency data would be implemented across 19 ministerial HQ buildings.

Real time energy meters help departments identify when and where energy is being used and assist them in trying and finding ways to reduce that energy use. The greater adoption of controls technology and the installation of the sensors needed to measure temperature accurately represent an obvious route in helping to achieve many of these objectives.

Retrofit offers big opportunities

And yet, in new buildings, project timescales for controls installation can often be pressurised. With traditional wired systems, this can impact adversely upon the ease, efficiency and time and labour costs associated with the controls installation process. Existing buildings account for more than 70 per cent of the entire market so retrofit offers a bigger opportunity for energy savings than the new build sector.

However, here, 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. 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.

One example is our new SonNet range of wireless temperature and relative humidity sensors, which were shortlisted in this year's HVR Awards for Excellence. These 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 self-healing, wireless tree topology designed to eliminate 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.

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.

• Alan Braybrook is sales and marketing director at Sontay