At 135m, the Coca-Cola London Eye is the world’s largest cantilevered observation wheel. The 32 ovoidal capsules offer visitors a panoramic view of London, and the attraction is open for visitors all year round, in all weather.

Working alongside the Sweett Group, temperature control specialist Dunham-Bush has recently upgraded the capsules with a temperature control solution to ensure visitors can enjoy views across London no matter the weather.

Managing director of Dunham-Bush, Mike Holding, said: “Each eight metre 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. The ride is around 30 minutes which means comfortable conditions within the capsule need to be achieved as quickly as possible and then maintained for the remainder of the ride.

“Extremes of temperature and humidity must be managed: from the environments that crowds of visitors on hot sunny days create, to visitors with wet coats on rainy days. Not only do passengers need to be comfortable on their journey, but the glass in each capsule must remain free from condensation to ensure a clear view of the capital.”

Dunham-Bush designed and manufactured a climate control system to be installed into each of the 32 capsules. This new system was developed to improve comfort and prevent condensation through temperature and humidity control, and fresh air introduction.

Mr Holding said: “Under the floor of each capsule is mounted a two-circuit 15kW air cooled chiller module, each 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 also used to pre-condition 280lt/second 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.”

He continued: “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.