Electronically Commutated motors and fans are playing a big role in cutting down energy consumption in Europe and North America – directly reducing the carbon footprint. EC Technology has arrived in the Middle East.
In any motor, either the rotor or the stator must have a rotating magnetic field in order to cause the motor to turn. This rotation can be accomplished by three-phase AC power, or single-phase power with some sort of circuit element like a capacitor, inductor, or resistance to synthesise a second phase or an electro-mechanical commutator to switch power to different coil groups as the motor turns.
The biggest limitation of AC power is that the frequency and voltage are constant, which makes speed control difficult. In the case of single-phase AC, phase shifting methods produce a very imperfect rotating field causing considerable losses in the motor or a very weak starting torque.
An electro-mechanical commutator can help achieve wide-range speed control, and high starting torque. The limitation is that it has friction and wear problems that reduce efficiency and require frequent maintenance. In addition, to ensure speed control, a voltage controller becomes a must.
To understand the significance of EC technology in the emerging green economy of the region, Earthwitness caught up with Jochen Friess, managing director of ebm-papst Middle East.
Friess explains, “EC is a different motor technology; the motor is driven by a DC voltage. With EC technology it is possible to realise any kind of speed without any kind of limitations and most importantly without any drop in efficiency. So this makes speed control with EC fans quite easy and it is possible without losing any of the efficiency.
“On top of that EC motors compared to AC motors, even if they run at full speed, they already have a higher efficiency than normal motors. They have lower power input and providing the same performance or higher.”
With EC fans, energy saving is the main feature – making it environment friendly technology. “During speed control you don’t lose any efficiency. And if you reduce the speed (RPM) of the fan by 10%, the power input gets reduced by 25%. It is possible to connect our fans directly to a sensor – that means the fans will always run at a RPM which is actually required. A standard fan, which is not speed controlled will always run at full speed.”
Getting into more details of how energy is saved, Friess says, “An EC fan with intelligence will only run at the speed to supply enough cool air, which is required depending on the sensor signal. If I have set the sensor signal at 24 degrees, so the fan would cool down the room to 24 degrees and then reduce the speed; that’s where the huge saving comes. If you reduce the RPM by 50% you only have a power input of about 17%, in comparison to full speed. The power consumption is a third of the RPM and that makes the whole concept very interesting regarding energy saving. Speed control is a solution to reduce power consumption.”
According to Friess, the market penetration of EC fans in the Middle East is slightly less than five per cent, which is very low. Given the increased interest in green buildings and LEED ratings, EC technology will be in focus very soon. ebmpapst has been promoting the technology through media and seminars, with a special focus on the consultants in the region.
Friess admits that the consultants in the Middle East literally dominate the decision making when it comes to the use of technology in buildings, and as luck would have it, most consultants are not aware of the technology and the cost benefits attached to it.
Freiss claims that ebmpapst has been studying the aerodynamics of the fans, including their conventional AC fans, and have succeeded in achieving power saving of 25%, by using highly efficient aerodynamic blades. ebmpapst started its Middle East operations in Jebel Ali in February 2006, Friess adds, “Our main customers are manufacturers of air conditioning equipment. Our biggest customers are in Iran, Saudi Arabia, Egypt and UAE. But UAE covers about 20% of our sales.”
Talking about success stories, Friess is very proud of the success they have had in such a short time in the region. “We had probably the biggest EC project worldwide, which was realised in Saudi Arabia for the Panda Hypermarket. They built a completely new distribution centre for both dry goods as well as cold storage goods. The whole facility is equipped with EC fans. This covers more than 70,000 sqm of storage area.”
The Panda Hypermarket distribution center is located in a remote area, and has problems with a steady power supply. ebmpapst took on the challenge, “It was important for them to use high efficient products to reduce the overall power consumption. They also used EC because they have a fluctuating power supply. The EC technology allows them to have a fluctuating power supply without a fluctuating air performance supply.”
The distinct advantage delivered in the project is that the EC fans keep a constant RPM as long as the power supply doesn’t drop below 60-70% of voltage. There was also considerable cost saving in installations as expensive control systems are not required to be installed with the EC technology.
As for the ROI, Friess says, “It depends very much on the application – how many hours the fan is running, how much control you have. If the fan is always running full speed then there is not potential to save. If you have fluctuating demand of cooling capacity of the fan then there is huge potential to save. In Europe we have an ROI within 18–20 months.
The green economy is here to stay; Friess expects the market to embrace the green values it so loudly proclaims. The optimism is not lost on Friess, “Everybody is talking about green and sustainability. I guess that is how it starts – first there should be discussions, and with time people get convinced.”
With Panda Hypermarket in Saudi Arabia ebmpapst has provided the region with a HVAC/R roadmap on substantial energy saving. Given the ROI is achieved in less than two years; the savings on energy can help companies in the region to be more competitive.
