Coolers designed to work with passive cooling systems

The combination is suited to protecting remote and mission-critical control and instrumentation equipment. The two cooling technologies can work together to handle extreme climatic conditions, or maintain continued operation in the event of one system failing. Should electrical power fail completely, the passive cooling system continues to operate indefinitely - maintaining low shelter temperatures until maintenance work can be performed. The new family of water coolers - dubbed Hybricool - are housed in tough GRP enclosures, which are suitable for use in the harshest of environmental conditions.

Intertec's Hybricool water coolers offer an IP rating of IP65 and can also be provided in versions suitable for use in hazardous areas. A range of sizes and cooling capacities allows users to select optimal cooling solutions for all common scales of outdoor protection applications from enclosures, to larger cabinets and walk-in shelters.

The main target application for the new water cooler family is enhancing the performance and reliability of shelters and cabinets fitted with passive cooling - a technology that operates by natural convection and requires no electrical power. Intertec's passive cooling systems typically employ water as a medium to store the coolness of the night and use it to moderate temperatures throughout the day. This form of cooling is widely used for 'off grid' applications where electrical power is unavailable and/or unreliable, and in remote locations, such as on SCADA systems for pipelines and oil and gas wellheads.

A passive cooling system can typically limit the maximum internal temperature of cabinets and shelters to around 10°C above minimum night-time temperatures - making it suitable for applications in arid and desert climates. The addition of an Intertec Hybricool water cooler reduces the dependence on low night-time temperatures, opening up applications in a much broader range of climates and geographical locations. Such hybrid or 'semi-passive' cooling systems - combining active and passive cooling technologies - can easily be configured to maintain internal shelter temperatures at 20°C or less.

Hybricool operates on the refrigeration principle, and has a closed loop system with four main components: compressor, condenser, throttle and evaporator. The evaporator is a heat exchanger element that can be installed inside the water storage tank of a passive cooling system to decrease temperature. The interior and exterior compartments are isolated to keep any outside weather from entering the cabinet or shelter. No filters are required, as the condenser - which sits in the external compartment - is coated with a special dust protection system. The coating also ensures advanced protection against aggressive media. No condensate is formed, and no icing is possible, due to the direct thermal transfer to the water buffer. Hybricool can be controlled to suit the application, such as by timer, or regulated by thermostat.

Intertec expects the combination of a Hybricool and passive cooler to allow process instrumentation and control engineers to create highly reliable cooling strategies for critical equipment - with a high degree of failsafe redundancy. When electrical power is available, the cooler feeds cool water into the cabinet's passive cooling system to provide a highly efficient cooling mechanism. If the cooler should fail for any reason - because of an electrical power loss for example - the passive cooling system retains enough capacity to keep a cabinet or shelter cool for several days, allowing plenty of time for maintenance to take place.