Drives&Controls & BACK TO BASICS n SPONSORED BY Raising efficiency without sacrificing comfort There’s more to e ciency than simply turning down the speed of a motor. ABB’s Carl Turbitt explains how plant optimisation, and using a drive’s intelligent control functions, can unlock e ciency in HVAC systems without impacting the building’s occupants. There is only so much e ciency you can achieve before you start having to make trade-o s on the job a system needs to do. In HVAC applications, for example, systems have to ensure that buildings are kept at a comfortable temperature and su ciently ventilated to reach the required level of air changes per hour. In theory, you could achieve maximum e ciency by switching the whole system o , but this is obviously unrealistic. It may be tempting to slow down the pumps and fans to the lowest speed that occupants will possibly tolerate, in order to eke out as much e ciency as possible. However, doing so will inevitably have a negative e ect on occupants’ comfort levels within the building. In HVAC applications, in particular, we often nd that engineers are not aware of what else a drive can do to improve e ciency other than varying the speed of the motor. Even then, we nd countless examples of drives that aren’t commissioned correctly, set at one xed speed, and then just left to run inde nitely. When you embrace the intelligent control functionality within the drive, you can have the best of both worlds – signi cant e ciency gains and an optimised system – without compromising on comfort. Many building management systems will already have sensors measuring temperature, CO2, pressure, humidity, occupancy, water ow and more. In many cases, these sensors can be wired directly to the drive rather than duplicating BMS I/O, thus saving on additional cabling and ancillary costs. For example, the drive can take the sensor signals and use its in-built PID control to maintain the correct setpoints depending on actual requirements at a given time. In a cinema, this could mean using occupancy sensors to lower or increase the speed depending on occupancy levels. In a leisure centre, it could mean using the drive’s time clock to reduce pump speeds during o -peak times. It may sound obvious, but many sites simply do not do it, and as a result are potentially missing out on signi cant energy savings. Crucially, these savings can be achieved simply by using what you already have, with no negative impact on the building’s operations or occupants’ comfort. To nd out more about ABB’s HVAC drives, search for “ABB ACH580”, or contact carl.turbitt@gb.abb.com. applicat for ov reliable Super r f rmo tions ving cables online stock,p huge UK pricing K tions,
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