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Advanced Engineering 2020

NEC, Birmingham(B40 1NT)

04/11/2020 - 05/11/2020

The UK's largest annual advanced manufacturing trade show, Advanced Engineering is your opportunity to (more)

Drives & Controls Exhibition

NEC, Birmingham(B40 1NT)

25/01/2021 - 27/01/2021

The show brings together key suppliers of state-of-the-art equipment representing the multi-tasking culture (more)

Variable speed in HVAC

Variable speed in HVAC
Danfoss has been producing VLT drives for 44 years applied to many different applications and was the first drives company to truly recognize the HVAC market opportunity. The HVAC "project" was started via a market research in the eighties. 

In 1986 the first VLT drives to be dedicated to HVAC and labelled HVAC were established and in 1987 the first installations were being implemented in Germany and Denmark. A new business was born - a business that has contributed significantly in establishing the VLT brand and global market position. Since then, Danfoss has been a leading player within the HVAC industry. Today, we are proud that many major industry leaders are some of our customers.

Primary focus in the first years was on Germany as it has the technological leadership. With a dedicated product portfolio and a dedicated organisation, the business founded a starting point to grow from.

In the 1990s we began the process of globalising the business. The primary focus was all about market development, as 95 percent of the market did not yet exist, so we focused our approach towards the consulting engineers of the world. Our belief and dedication paid off as the application of drives designed and dedicated to HVAC applications and environmental needs was embraced and sought after by the consulting community. 

In the early years, the focus was on fan applications. As Variable Air Volume systems (VAV) were being designed by the consulting community to better serve buildings with variable occupancy profiles, the emergence of variable speed took over from Inlet Guide Vane systems. VFD's were seen as delivering increased energy savings and performance at part load conditions, during low occupancy periods and were considered as having a higher system reliability.

Utilizing VFD technology to best match load to demand expanded further as a design concept to also address seasonal variances as well as geographical variances in climate. Application expanded into pumping systems on secondary pumping circuits and eventually also onto the condenser circuit in cooling systems as well as Cooling Towers.

During this period the technology continued to develop with focus on the Commercial Buildings environment and associated needs. Developments included: Robustness of enclosure design, integration of EMC Filters to reduce radio frequency interference / electrical noise, integrated harmonic filters to minimize harmonic distortion of the quality of the mains supply all leading to a higher robustness and reliability. At the same time, learning's from the actual application by M&E Contractors, AHU & Pump OEM's, Controls equipment manufacturer's helped to advance the functional application and integration into the building environmental control system. This resulted in specific fan and pump software functionality being designed into the drive to enhance the application control as well as application diagnostics to a predictive maintenance level.

Fast forward to today and VFD's are now widely used not only in fan and pump applications within the building environment, but now are being increasingly applied on compressors. We now see variable speed being applied on large & medium tonnage Centrifugal and Screw Compression chillers and are starting to see this to cascade down into the smaller tonnage light commercial scroll chiller systems. The primary driver is improved part load efficiency and the general movement toward higher efficiency in building HVAC systems driven by a combination of various Industry authorities and legislation as well as innovation in the OEM's designs.

For many years the traditional motor technology applied in HVAC systems has been the Asynchronous Induction motor design. VFD motor control algorithms were designed around his motor technology and most VFD's can run any Asynchronous IM. But in recent years, the strive for higher efficiencies and efficiency classification has brought forward more motor technologies, some old and some new. One of the more prominent is Permanent Magnet Motor technology, using either rare earth magnets or ferrite cores that can deliver a higher motor efficiency. This has challenged VFD manufacturer's to improve and also modify their motor control algorithm's to control these high efficiency motors. Danfoss, whilst wishing to remain motor independent, has developed its range of frequency converters to also control high efficiency permanent magnet motors. Danfoss EC+ solution enables the designer & OEM to select the most efficient individual components, for example, most efficient VFD / motor / fan to optimize the total system efficiency and system reliability & serviceability. There are other on-going motor technology developments and there will be more written on this technology chapter going forward.

Another development has been the adaption of VFD technology to be mounted on the motor. Danfoss was one of the first to produce a Frequency Converter motor or FCM many years ago and which is still applied today on fans & pumps by the OEM's. Partly driven by OEM design, but also by the EuP legislation, we foresee an increase in the application of VFD technology as an integral part of the motor. Danfoss is releasing its next generation FCM in 2013 offering both standard efficiency Asynchronous and permanent magnet motor high efficiency solutions.

The utilization of VFD's in HVAC system design is set to increase as it is seen as one of the most attractive, proven and affordable technologies to contribute to higher efficiency systems reducing energy consumption and carbon emissions. Danfoss has delivered more than 2 million dedicated HVAC inverters in it are now more than 25years of focusing on the HVAC Industry. We estimate that this has contributed to a reduction of 232million tonnes of CO2, equivalent to the annual emissions from approx. 80,6million cars.

Through this experience and by learning from and listening to customers, the 2013 product portfolio of Danfoss reflects an expanded portfolio of HVAC dedicated products and supporting tools. In all to meet the broader application demands, in particular in the growing OEM sector as the market continues to evolve. The products are supported by trendsetting campaigns such as EC+ focusing on the customer desire for increased efficiency in their HVAC Systems. Also, an expansion into the refrigeration business based on the HVAC business model will be in focus in the future.

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