Following the refurbishment of a number of its air handling units, Belfast International Airport is hoping to make annual energy savings of 1,000,000kWhrs.
Following the previous success of retrofitting variable speed drives (VSDs)s to two 30kW circulating pump drives, it was decided to fit variable speed drive control to the 28 fans on the AHUs covering 35 to 40% of the main airport: “From past experience we knew VSDs could offer substantial energy savings and with rapidly rising electricity prices, and prompted by the availability of a 30% grant from our energy supplier, Energia, under their energy efficiency scheme, we decided to refurbish a number of our air handling units with variable speed drive control,” said airport technical supervisor Colin Sloan.
28 Danfoss VLT®6000 Hvac drives, supplied by Greenville Electrical, were installed and commissioned, initially with the drive outputs limited to 30 – 37Hz, pending full commissioning of the air quality monitors. Despite the hot summer conditions, during which the air-con system functioned satisfactorily with the fans at 80% speed, the actual savings exceeded expectations and the energy bill was down by over £15,000 for the three month period. In cooler weather conditions, it is anticipated savings will be even greater, especially with the AHUs under full automatic environmental control.