Breaking down the cost of sensors

sontay1 Alan Braybrook, Sales and Marketing Director at Sontay, explains what specifiers should be looking for when assessing value for money in HVAC sensors.

No one likes to feel they are being short changed but extra charges for items seem to be common place in today’s world. For example, you buy a seat on a budget airline for £5 but by the time you have added on the extra costs for luggage, seat selection and booking fees you would probably have paid the same amount as you would with a more expensive operator. And you would fly to an airport in the city rather than be flown 100 miles further away than you’d wanted.

This value assessment translates well into the world of HVAC controls, and specifically sensors. We do not like putting up with extra charges outside of work so why do we put up with them inside work? There a few simple things specifiers and contractors can do to make sure they are not spending more than necessary on hidden extras when it comes to sensor equipment.

This equipment is vital as the eyes and ears of any control system and yet comparing products like for like is a challenge. At a basic level, the cheapest sensors require extra components, priced and supplied additionally, to deliver the same functionality as a more expensive product. Factor in the extra time and installation cost required to achieve these equivalent results, and what appears initially to be the cheapest sensor clearly does not equal best value.

Increased risk

Selecting the lowest cost sensor can also bring with it the increased risk of compromising on long-term measurement, reliability and performance stability. Accounting for just 2% of the budget for a whole project, room sensors themselves are not always the main focus of attention when it comes to selecting and specifying the building control system. However, device failure can lead to the time and cost of unnecessary call out and product replacement issues, alongside the unwanted cost of reputational damage to the specifying contractor and consultant.

The industry needs to navigate away from single use sensors – one for temperature and one for humidity – to single, multifunctional environmental sensors. These modern devices may appear more expensive but they can measure different important variables within the overall space conditions which may include air quality, CO2 for occupancy alongside traditional temperature and humidity measurements.

For example, our GS-CO2-AQ-RHT all-inone sensor has been designed to measure CO2, air quality, relative humidity and temperature. The sensor offers long term stability and accuracy for all measured parameters providing an extremely cost effective solution. This combined approach brings much greater value to contractors and their clients. The building owner enjoys the ability to monitor and report on total environmental conditions and yet service only a single device in the future. They can also minimise the wall acne that will often occur if multiple devices are required. The systems integrator, meanwhile, has the ability now to provide much more sophisticated control strategies at a lower total installed cost with fewer devices to install and service in the building.

Wireless sensors

The growing popularity of wireless sensor technology is also having a fundamental impact on transforming how we think about sensor installation. By eliminating the need for structural cabling during sensor installation, wireless 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. In projects which feature our SonNet family of wireless sensors, we are typically finding total installed cost savings of 30% and more over comparable wired sensor installations. At a time, when reducing costs are a priority on many projects, proven wireless technology can bring significant benefits.

sontay2Enabling sensors to be compatible with current building control systems aids the integration of wireless technology and adds another element to the sensor package. We have introduced the Tridium NiagaraAX driver to our SonNet network radio receivers to enable quick and seamless integration with Tridium’s range of JACE controllers as part of a NiagaraAX framework for building control systems. This opens up the system to BMS protocols such as BACnet, LonTalk and Modbus.

The new driver ensures Sontay’s RFRXS 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.

Good design

Design layouts in commercial buildings are also changing and there is more emphasis placed on the aesthetics when installing sensor equipment. The cheapest packages often do not have the look and design quality end-users want to see on their walls, leading to the dreaded wall acne.

Up until now, sensors located in the space have been selected with little or no regard to design aesthetics. The best devices available on the market offer an opportunity for specifiers not simply to satisfy the functional demands of their client but also the impact the sensor has on the interior space. Take our new range of TT-1000 space temperature sensors. These room sensors feature a specially designed low profile and curved fascia to ensure that they can blend stylishly and seamlessly into a room’s design scheme whilst still helping to deliver greater energy efficiency, cost savings and carbon reductions in new build and retrofit building applications. The bland and, frankly, cheaplooking design of the ordinary room sensor need no longer be a barrier nor an unwanted intrusion into the design scheme of the upmarket commercial office building.

Well-made devices are capable of providing a better picture of the true building conditions over the long term in smaller, more pleasing to the eye packages. The result is the creation of a broader market opportunity for control systems specifiers and installers and, ultimately, the potential for more energy efficient buildings and reduced carbon emissions for all. In all parts of life, people are looking at what they get for their money – HVAC controls are no different.