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‘EER values set by regulators can only be reached by applying VFDs’

Rachid Assebbane, Market Sector Manager, A/C & Commercial Refrigeration, BITZER, in conversation with Surendar Balakrishnan of Climate Control Middle East…

  • By Content Team |
  • Published: June 3, 2022
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With demand control ventilation being seen as a viable solution to improve Indoor Air Quality, are we seeing an uptick in sales of VFDs across multiple building profiles, or has the pandemic done little to stir up the need for greater IAQ in the GCC region?

The Middle East, especially the GCC region countries, are strongly looking for intelligent and highly efficient solutions that serve the comfort demands as well as the need to reduce energy costs. Consequently, the demand for VFDs has increased considerably, similar to the demand for controlled ventilation even before the pandemic. COVID-19 has certainly emphasised the role of the HVAC system in providing healthy and safe indoor environment, which indirectly also supports growing sales of VFDs; and there is no doubt that IAQ will contribute to pleasant feeling in the indoor areas. With the right proportion of air leaving and outside air entering, it could have an effect on limiting the spread of COVID-19 disease to a certain extent.

Finding the right air proportion goes hand in hand with demand control ventilation. VFDs play an important role here in the ventilation system to reach the required efficiency and precision level of required air flows. In the GCC region, the demand varies throughout the year. In the winter, the demand for cooled conditioned air is low, which is an opportunity to significantly minimise the energy costs by applying VFDs not only at the ventilation system but also at the chiller or VRF level at the compressor.

Is the growing popularity of VRFs triggering a greater demand for VFDs, considering that they are an ideal fit to control the operating speed of the compressor in a VRF system to match the load, which helps in reducing energy use in part-load conditions?

Rachid Assebbane

Cycling the compressors according to cooling demand is no longer an option – it’s not energy efficient; and starting on the compressor frequently reduces the life of motor and the moving parts drastically. It’s well known that a VRF system can only run efficiently if the compressors and fans are equipped with VFDs. The ability to match the fan’s  motor/compressor load to system load makes such systems run efficiently at part load while providing a precise control and meeting the comfort demands. Definity, VRF systems have contribute positively to VFD sales, but the growth rate in the GCC region market, compared to the rest of the world, is still slow; thus, the support in VFD sales through VRF is still limited. On the other hand, other sectors, like HVAC chillers, and other fields, like commercial and industrial refrigeration, are experiencing a faster growth of implementation of VFD technology.

What is the market demand for drives across the GCC region?

The regulations for energy efficient solutions are getting tougher across all the GCC region countries aiming to reduce energy consumption and indirectly reduce the generated greenhouse gases for more environment friendly buildings. In many new projects, the set EER values by the regulating authorities can only be reached by applying VFDs. The discussions with our customers, the HVAC manufacturers for planned projects in the GCC and Middle East regions also forecast a rising tendency.

How strong is the trend of manufacturers of HVACR equipment incorporating VFDs in their systems, which does not necessitate retrofitting them? How has this opened the market for you as a manufacturer of drives?

Retrofitting is a part of the HVAC manufacturer business – it brings not only energy saving to the system, but it also offers a very precise control of the compressor, fan or pump to meet the load requirements. However, in order to efficiently use VFDs in existing systems, a closer look of all the components must be taken into account. The opportunities in the market are huge but the trend is still not meeting the expectations, as is the case in Europe. For sure, the retrofit projects executed with our VFDs are acting as a marketing tool for our brand and are helping us acquire new business with either new retrofit projects or new installations.

Are we seeing greater demand for VFDs from the residential market?

VFDs are nowadays required almost in all the applications, and in all the market sectors; the residential market is one of them. The authorities as well as building owners are seeking to reduce the energy bill and reduce the CO2 footprint. The demand is clearly present not only for the residential market but also in commercial refrigeration and industrial refrigeration.

The pandemic revealed a new occupancy profile (lower occupancy) in the commercial real estate market. How is the trend shaping future thinking among building owners, in view of the possibility of future possible pandemics (building preparedness) or even the possible revival of lockdowns in case of further waves in the current pandemic?

The use of VFDs has proven to be advantageous under normal conditions in the pre-pandemic time. That said, the paybacks compared to conventional fixed-speed applications, especially at low occupancy profiles during COVID 19 have made VFDs an essential component in the HVAC system.

The uncertainty of future similar lockdowns has made VFDs even more attractive for building owners to apply them. With the VFDs, facility managers have the possibility to ramp up and down the system within a big range – for example, from 15% to 100%, according to the cooling demand. The system can also operate continuously, providing a continuous and steady cooling unlike the traditional on/off cycling method.

The VFD sector has seen greater use of electronic and controls technology. Are building owners enthusiastic about integrating smart VFDs in their facilities, given the fact that Indoor air quality is improved as controls respond to better control temperature, humidity, pressure and carbon dioxide (CO 2 ) levels in buildings?

A long time ago, well-known VFD manufacturers recognised the importance of using intelligent VFDs that not only control the motor speed according to the load to achieve optimum energy efficiency but also offer a monitoring of important parameters by processing the signals from the several sensors installed in the building to help keep a precise control of the room temperature and a better IAQ. Nevertheless, we do still see the need to make the owners more aware about the possibility of integrating smart VFDs in their facilities with the support of our direct customers, the OEMs, the contractors and the distributors.

There is talk of doubling the use of VFDs as smart sensors in HVACR applications. How is this helping in predictive maintenance and condition-based monitoring?

Reliable operation of the system and durable components are nowadays a necessity in the HVACR industry. With the help of the sensors connected to the VFD, measurements data logs are being saved and can be downloaded and analysed on a regular basis.

Has the reduction in cost of VFDs encouraged building owners to opt for them? How successful have you been in highlighting the benefits of VFDs to building owners, such as reduced startup shock and smoother changes in fan speed and, further, reduced maintenance through lower wear and tear, which increases the life of the fan motor?

With the sales volume increasing, the production costs reduce, and thus, the price of VFD systems become more competitive for the building owners. We do have calculation tools that compare traditional fixed-speed systems with the variable-speed systems in terms of energy cost savings, which in turn shows the high ROI over a shorter period; this is, of course, the most important selling point of the VFDs that the end user should clearly understand. These comparisons are based on big amount of data collected from the field over the years. We do offer trainings, as well, to our customers showing all the benefits from the reduced inrush current to the smoother and continuous operation, which both help in extending the lifetime of the moving parts and the winding of the motors. Continuous monitoring of the operation of the compressor or fan or any other component run by the VFD enables the operator to act in a preventive way and repair components or, for example, adjust system/component settings before a damage occurs to the system.

Have owners budged on realising that the initial cost of a drive is only about 10% of the total cost of ownership?

Almost all owners have understood there is ROI when using VFDs after only a few years; however; not all of them are aware of the low initial cost to be invested versus the total cost of ownership. There is still a lot of education work to be done at the owner’s level. We do rely on the HVAC OEMs and contractors to support us in forwarding our message to the end-users, the developers and the consultants about the clear contribution of VFDs in reducing the energy bills and, thus, also the carbon footprint by making a small initial investment.

Would you say we still have numerous instances of uncommissioned VFDs, which are as good as not installing VFDs, in the first place? Are you seeing a shift in market behaviour towards proper commissioning, or is there still frustration over not getting the maximum out of the drives?

Such issues are no longer existent in our market. We are delighted by the increasing positive response of the successfully commissioned VFDs in the field. The operators are nowadays well trained to fully use all the VFDs functions, and if it’s not the case we, as a company, do support with the commissioning onsite with specialised engineers. We do have commissioning packages that meet such demands.

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