2012-04-02 - A project to upgrade the Air Handling Units (AHUs) at Manchester Airport with ABB low voltage drives and ABB high-efficiency IE2 motors is saving annually 4,000 MWh, as well as cutting CO2 emissions by over 2,000 metric tons a year.
ABB HVAC drives were selected because of their user friendly robustness and ability to integrate with the existing building management system (BMS) via BACnet protocols, allowing monitoring of a new high efficiency filtration system.
Mr. Andy Sheridan, Service Facilities Manager for Manchester Airport, says: “The ability of the ABB HVAC drive to use BACnet to communicate / integrate with our BMS is one of the key reasons for choosing them, as we knew we would be using these filters that could send signals back to a filter management system. Existing drives could not meet this requirement so cost effectively.
ABB replaced all of the 220 AHUs’ drive motors with IE2 high energy efficient motors, ranging between 3 to 90 kW. In addition to the original design is the inclusion of 110 variable-speed drives throughout Terminal 1, 2 and 3.
Mr. Sheridan says: “The airport has a commitment to achieve carbon neutrality by 2015. Together with our need to reduce costs and our environmental commitments, looking to improve the air handling in the terminals was an obvious choice.”
Manchester airport has made extensive use of ABB low voltage drives already in applications as diverse as escalators and pumping solutions. “We generally specify ABB drives now across the airport,” says Mr Sheridan. Paul Percy, Director of Massey Coldbeck Engineering and his technical team, the airport’s heating, ventilation and air conditioning (HVAC) specialist, recommended ABB drives and motors and installed all the drives for the airport energy saving project.
River of lights at Terminal 1
Working with members of the ABB Energy Appraisal Team, Massey Coldbeck Engineering carried out extensive trials on two identical AHUs, which serve the Terminal 1 check-in hall. “Areas of Terminal 1 are some 50 years old,” says Mr Sheridan, “And the normal practice at the time was to oversize motors running at 100 percent controlling airflow by throttling discharge dampers. By installing the latest ABB IE2 high efficiency motors and resizing for greater efficiency, energy savings of five percent can be realised.”
To prove the savings, Massey Coldbeck Engineering installed permanent half hourly data logging energy meters and monitored the readings over a six month period. By reducing the set point from 100 percent to 80 percent, it was shown that savings of over 50 percent could be made with no impact on air quality delivered.
Total calculated annual savings for the scheme’s high efficiency motors and drives equate to approximately 4,000 megawatt hours (MWh). “This saves around 2,200 metric tons of CO2
a year,” says Mr Sheridan. “We have a target to reduce our CO2
production by 27,000 metric tons a year, so this one application has reduced our emissions by 10 percent of our target, which for us are very compelling numbers.”
Whilst the AHU modification produce year on year energy savings, the high efficiency air filters require constant condition monitoring and the replacement of filters at the end of their serviceable life. Previously this would have been carried out by manually checking and recording the differential pressure indicators and trend plotting the readings. Massey Coldbeck Engineering, together with Manchester Airport’s engineering and Utilities working group and Western Automation, engineered a solution to monitor the filter pressure drop and air velocity via electronic sensors connected through the ABB ACH550 analogue inputs and onto the airport BMS workstation via BACnet protocol.
All the AHU HVAC drives are connected via the project installed Master Slave / Token Passing (MS/TP) EIA485 network to local BACnet routers and onto the BMS front end, this can eventually be linked to the airport Chroma system. This is a passenger and aircraft movement protocol, which will eventually dictate air quality, heating and lighting requirements relative to passenger levels. “Once completed the system will alert the necessary facilities managers of any filters that require replacement, and will also e-mail our system maintainers directly so that they can carry out the necessary replacement works.”