It is more usual for process chillers to be used in factories or in the plastics industry but the fish in Southend’s Sea-Life Adventure seem happy with their lot. HVR reports
WHETHER the water temperature is at the correct level in the tanks is, perhaps, the last thing on the minds of visitors to Sea-Life Adventure in Southend.

But, as they wander from exhibit to exhibit and underneath the glass corridor that provides an up close and very personal view of the centre's many sharks, it is thanks to water cooled by Tricool's process chillers, that the sharks and a wealth of other varieties of fish including Smooth Hounds, assorted urchins, sea horses and Piranha co-exist quite happily.

Careful control and constant monitoring of temperatures and salinity, along with a purpose-built cooling system, much of which was built by one of the centre's own aquarists, provides visitors with a valuable insight into the habitats of sharks, eels and some rather exotic fauna. in differing aquatic climes.

Sea-Life Adventure is independently owned and operated by Miller Leisure on Southend's famous seafront and near the world's longest pier.

The complex comprises two inter-linked buildings which contain 33 tanks on the main display floor and 30 in the other for quarantine, rehabilitation and breeding purposes. Three additional displays are home to the critically-endangered Mexican Walking Fish or Axolotl.

The other tanks in this the sea nursery section, are home to a variety of crustaceans. These include Freddie, a land hermit crab from Zanzibar who was captured in a Southend flat after unwittingly arriving in the UK via a shell brought back from the beach as a souvenir!

The Ocean Tank holding 195,500 litres of seawater is the largest tank and home to a mix of aquatic exhibits varying from the well-known Mullet to the more unusual Trigger Fish named Daryl!

The tank replicates a natural environment as the Southend estuary is the point where the North Sea meets the Channel and provides a rich habitat for a wealth of varieties of fish, shellfish and plant life.

Temperature control is critical for the Ocean Tank. Although a stand-alone tank, like all the others it is fed directly with sea water.

Too cold and the fish become 'skittish' and easily startled, too warm and like humans they become lethargic and lose their appetite. Maintaining the temperatures to address the needs of all its occupants is a balancing act. Cod and Mackerel dictate requirements with temperatures maintained between 14-15ºC.

Sea-Life was relying on a single stand-alone custom-built chiller installed 10 years ago to regulate temperatures for all of its tanks.

Age and the demands of a rigorous and exposed salt-laden environment all took its toll with breakdowns becoming a regular occurrence. During the day, the chiller was cooling the water for the smaller tanks and at night was switched over to cool down the larger tanks. A natural switchover meant that while one tank was cooling down, others were heating up causing swinging temperature fluctuations and an uncomfortable environment for Sea-Life's living exhibits.

Tricool was asked to design a solution while addressing, space limitations, energy efficiency and durability. David Knapp, Aquarium curator also had his own ideas of where the chiller should be sited and exactly where he wanted the pipe runs to feed the tanks.

With space at a premium in the plant room, the design had to make maximum use of space and provide easy access for maintenance.

At the heart of the design is one of Tricool's customised Series 2007 process chiller based on the Series 2000, specifically designed to cope in demanding environments.

The unit features a titanium heat exchanger and electronic temperature control with non-ferrous wetted parts. It was installed externally surrounded by a custom-built housing to blend in with the building's design and aesthetic appearance.

With maintenance a key issue for Sea-Life's own engineers, a large easy-to-clean condenser was essential and David ensured it was fitted at the far end of the plant room in line with the re-circulating tanks but backing on to the chiller, therefore affording direct but shorter pipe runs. A special coating suitable for a saline atmosphere was also fitted. It was also designed to ensure maximum compressor capacity at high ambient conditions and the condenser air is discharged vertically.

An aquatic environment is not the usual run of the mill application. To cope with the demanding environment and to address the centre's own specific requirements, Sea-Life also requested a number of non-standard features. These included a level fluid sight glass for the internal water tank, three-way valve to provide 'straight line' control and the ability to adjust heat when necessary.

Because of the working environment and close proximity to the sea, the chiller is subject to regular checks. Salinity levels are closely monitored. Too much salt could damage the chiller system and prove detrimental to the fish. However, Southend is some way down the estuary and there is some protection and salinity tends to be stable. Temperature fluctuations on the other hand are a major concern.

'We rely on the chiller year round,' says David. 'But it is not needed so much in the winter months when the ambient water and air temperature falls below 12ºC.'

The chiller comes into its own during the summer. Then the sun beats down on the mud flats, which accumulate the heat and act as huge radiators, heating the water up as the tide comes in. It therefore takes a while to cool the water down and while regular sand filter backwashes are also necessary, David has to be careful that not too much warm water is added to the tanks.

The chiller is a reliable workhorse and underpins the entire infrastructure.

'Our business focuses on education and conservation as well as presentation of the sea's creatures and their habitats.

Temperature control is prerequisite so that creatures like Daryl can be carefully displayed in as near to their natural habitat as possible.'

Tricool (01489 584006