Mike Holding, MD of Dunham-Bush, explains: “Each 8m capsule fitted to the London Eye needs specific environment-control requirements depending on time of day, number of passengers and prevailing weather conditions as the London Eye rotates. Extremes of temperature and humidity must be managed: Not only do passengers need to be comfortable, but the glass in each capsule must remain free from condensation to ensure a clear view of the capital.”

Holding continues, “Under the floor of each capsule is mounted a two-circuit 15kW air cooled chiller module, equipped with four-scroll compressors, two plate heat exchangers and two air cooled condensers fitted with EC fans. Two Dunham-Bush type VBH 1200 Q air handling units (AHUs) each equipped with cooling coils, filters and electric heater elements are used to pre-condition 280L/s of fresh air before the introduction into the capsule. The modular arrangement allows a complete chiller to be lifted out of a capsule and replaced with minimum disruption to the operation of the attraction, should the need arise. 

“There are two Dunham-Bush ‘Panther 7’ fan coil units (FCUs) installed in the roof of each capsule to maintain comfort conditions in the space and to ensure the glass is clear. Our engineers had to adapt the initial design for installation at an angle to fit the roof void with multiple air discharge paths to distribute the air along the length of the capsule. 

“The AHUs and FCUs are controlled from a single controller which also monitors the chiller, ensuring a fully integrated system that responds to the prevailing conditions at all times.

“Once passengers enter the capsule and the doors close, the first obligation is to achieve the design temperature within the capsule through the AHUs. Once the temperature has been achieved, the Panther FCUs ensure comfortable conditions are maintained for the passengers for the duration of their journey.” 

All the capsules have now been upgraded and have been proven over at least one full season with excellent results.