Application Analysis in HVAC Industry – Frequency Inverters Reduce Energy Bills for a 5-Star Hotel

The Kempinski Hotel – Mall of the Emirates, part of the globally renowned Kempinski network, first opened in 2006. The central air conditioning system was built without frequency inverters, with no consideration for potential energy savings. The hotel climate was controlled through the building management system, and all air handling units operated at fixed speed only. Any airflow regulation was performed solely through adjustable dampers.

In summer, when temperatures in Dubai exceed 40°C, the air conditioning system becomes more important than an oasis in the desert! System operating costs represented a significant portion of the hotel’s total operating expenses, making it vital for management to find ways to improve system control and efficiency to reduce electricity costs. The company’s engineering team issued a tender, and after several meetings with GI Tech, Invertek’s trading partner in the UAE, it was confirmed that preference would be given to Invertek Optidrive Eco HVAC frequency inverters.

The Eco range was specifically designed for precise motor control in fans and pumps, using IE2, IE3, and IE4 motors, and can control all types of motors, including AC induction (IM), AC permanent magnet (PM), brushless DC (BLDC), and synchronous reluctance (SynRM) motors. Eighty-three drives, ranging in power from 2.2 kW to 22 kW, were installed in 43 AHU panels in various parts of the system—an installation that, as explained by GI Tech Director Ali Akhavenas, presented considerable challenges:

“During our initial site survey, we noticed several issues that made us think very carefully before submitting our final recommendations. In most locations, there was no space for new panels, and existing panels had very limited space to accommodate new equipment.”

By installing Invertek Drives Optidrive Eco frequency inverters in the air conditioning system at Kempinski Hotel Mall of the Emirates, up to 25% energy savings were achieved. The Optidrive Eco HVAC range is specifically designed for use in HVAC building service systems and enables energy savings by varying fan speed to regulate air conditioning system performance according to changing operational demands.

The unique Eco Vector motor control strategy is continuously adjusted in real time to ensure the most efficient operating conditions for the load, typically reducing energy consumption by two to three percent compared to standard AC drives. This ensures similar long-term cost savings by selecting higher efficiency without requiring replacement of previously installed equipment. The energy consumption audit commissioned by the hotel’s senior management after receiving several high electricity bills was the final confirmation of this assessment: it was determined that the HVAC system was exactly what was needed for both the hotel and the budget.

“As this is a luxury visitor facility, it was also crucial that the work be performed outside operating hours to avoid disturbing guests.”