September 2019

49 www.drivesncontrols.com September 2019 BUILDING SERVICES IE3 motors and VSDs cut energy bills by 40% at Madrid hotel T he world’s hotel industry is responsible for 1% of all global carbon emissions, according to the International Tourism Partnership (ITP). This figure is expected to grow as tourism continues to boom, with the total number of hotel rooms worldwide predicted to expand from 17.5 million to more than 25 million by 2050. The hotel industry regards sustainability as one of its main challenges, especially as an increasing proportion of guests regard green credentials as being a critical factor when making their travel plans. One of the world’s largest hotel operators is IHG (InterContinental Hotels Group). With more than 5,500 hotels and resorts in nearly 100 countries, IHG has set up a sustainability programme, called Green Engage, that helps its hotels to manage and report their use of energy, carbon, water and waste. The programme recommends more than 200 green measures, implementation plans and support systems to help the hotels to achieve targets, and recognises their progress through four levels. Between 2013 and 2017, the programme helped IHG to cut its energy consumption by up to 25%. And between 2018 and 2020, the hotel group is hoping to reduce its carbon footprint per occupied room by a further 6–7%. A key focus area in IHG’s energy reduction programme has been its HVAC systems, which can account for 60–80% of the energy consumed in a hotel. The InterContinental Madrid hotel, for example, has cut its energy usage by 445MWh a year by equipping its HVAC (heating, ventilation and air-conditioning) systems with variable-speed drives and high- efficiency motors. The five-star hotel, which hosts around 100,000 guests a year, has achieved all four levels of the Green Engage programme – the first in Europe to do so. The 65-year-old hotel has eight pump groups that serve its HVAC systems as well as hot water supplies for rooms, kitchens and other facilities. Although these systems were well maintained and in good condition, the hotel’s managers were concerned that energy efficiency levels were below best practice. They therefore called in a local firm, Exel Industrial, to carry out a detailed energy survey. This revealed that the hotel’s energy use was high, particularly in the existing baseplate pumps, where the motors and pumps were both inefficient. “The study showed that 40% of energy could be saved by decreasing the frequency of the motor by 10%,” reports Enrique Bernad Lillo, Exel’s quality and financial manager. In 2016, Exel installed 13 ABB HVAC drives and 16 ABB IE3 motors in new baseplate pump groups and integrated them into the hotel’s building management system. Using VSDs to regulate the pumps is providing the system with greater stability and considerable energy savings, because the motor speeds are now adjusted to match the precise demand at any given time. The drives andmotors also offer benefits that go beyond energy savings because they have helped to cut noise levels while offering smooth starting. This lowers the stress on the pumping systems, helping to extend maintenance intervals. The need for maintenance is also being reduced by longer pump operating lives, especially because the VSDs can eliminate the potentially harmful effects of pump cavitation caused by voids in liquids imploding near metal surfaces and triggering intense shockwaves inside the pump. Following the retrofit, the Madrid hotel is using around 40% less energy, saving up to 445MWh, and cutting its annual energy bill by more than £28,000, delivering a return- on-investment of less than two years. “This is a great example of how our variable-speed drives, combined with our high-efficiency motors are providing the most affordable, effective and sustainable means of saving energy and optimising operations for our customers,” says Morton Wierod, president of ABB’s motion business. The InterContinental Madrid is aiming for further reductions in energy consumption, and plans to share its best practices with other IHG hotels. The hotel has already cut its carbon footprint by 253 tonnes of CO 2 (carbon dioxide) a year. If similar energy savings could be replicated in a quarter of the world’s 187,000 hotels, global CO 2 emissions could be cut by nearly 12 million tonnes a year – similar to shutting down three coal-fired power plants. n Hotels account for about 1% of global carbon emissions. By retrofitting VSDs and IE3 motors to its HVAC system, a Madrid hotel has cut its annual energy bill by more than £28,000, resulting in a payback of less than two years. The InterContinental Madrid hotel has cut its energy usage by 445MWh a year by retrofitting VSDs (left) and IE3 motors to its HVAC plant