Adiabatic Retrofit – A lifeline for legacy chiller systems

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In 2022, the UK experienced a 40.3°C record-high temperature, putting a strain on many businesses’ cooling systems, The high temperatures were a wake-up call for the need to be specifying with more safety margins for new cooling equipment, and possible solutions for the legacy equipment.

Loss of cooling is a critical failure in data centres and no amount of resilience (N+1, N+N) can stop the problem of rising ambient air temperatures.  Consequences of raised temperatures can include:

  • Reduced performance and reliability of IT equipment
  • Increased risk of component failure
  • Increased electrical consumption as chillers operate at maximum capacity for longer periods
  • Breach of operator SLA (Service Level Agreement)

Tim Bound (Director at Transtherm) comments “Emergency response systems do not formally include stationing people on the roof with a hosepipe throughout the hottest parts of the year, but this is becoming an increasingly common practice and presents a great risk to the resilience of data centre cooling systems.”

Adiabatic Retrofit for chiller systems

One solution that has gained traction in recent years is adiabatic retrofit technology.  This technology bridges the gap between original air temperature design figures and on-site peak air temperatures, avoiding the possibility of overheating within the data centre and associated problems.

Injecting a fine mist of water into the inlet airstream can reduce the dry bulb temperature by 13-15°C in the UK, meaning if the original design dry bulb air temperature was 30°C, this will allow the chiller to operate in as much as 45°C.

One of the key benefits of an adiabatic retrofit is its cost-effectiveness. Rather than investing in a new chiller system to accommodate the rising temperatures, businesses can retrofit their existing equipment with adiabatic cooling technology for a fraction of the cost and without the need for a disruptive strip-out and install program.

The Transtherm system includes various safety features that control droplet sizing, UV sterilisation, risk of stagnation, as well as materials that actively repel Legionella bacteria, so you can be assured that the health and safety aspect has already been thoroughly considered.

Adiabatic Systems can save huge amounts of energy in hotter climates

Adiabatic systems are most effective in hot, dry environments such as Dubai.  Since the relative humidity in such locations is low, the opportunity to increase the humidity is larger and, therefore, the reduction in air temperature can be much greater.

In climates that have much higher average air temperatures, the adiabatic system can be run for much larger periods of the year and with reduced chiller air inlet temperatures of circa. 30°C, rather than up to 50°C+, the plant will consume less energy during those times.

Quick & easy installation

The installation process is quick and straightforward, and data centres can see immediate reductions in summertime dry bulb temperatures.

Transtherm’s adiabatic retrofit system includes everything you need:

  • An adiabatic wet box (which houses an inlet double check valve, filters, solenoid valves, UV sterilisation, spray booster pump and pressure reg valve)
  • PLC based control system (which controls the various spray, purge and sterilisation functions) that can either run in standalone mode or react to requirements from the site BMS
  • The required adiabatic spray bars
  • When running for longer periods in the year, air inlet filters

With all parts already included and pre-programmed for required site parameters, installing the system is extremely straightforward.  The adiabatic wet box and control system arrive mounted on a free-standing frame, the spray bars need to be attached to the chiller (using the clips supplied), interconnecting pipe work between the wet box and spray pipe will need to sorted on site and a drain pipe needs to be plumbed to the purge connection and that is it.  There are other control options for integration with chiller or BMS controls and these can be discussed on a job-by-job basis.

Environmental and cost-saving solution

The retrofit technology is designed to operate only when the ambient temperature rises above a certain threshold, which helps to conserve water and reduce maintenance costs.

Since it is designed to be compatible with legacy equipment, customers can save huge amount of money by adding an adiabatic system, rather than replacing the entire chiller.

In conclusion, adiabatic retrofit technology offers a cost-effective and sustainable solution for legacy chiller systems and can help keep data centres running within SLAs and in warmer climates can help to significantly reduce energy consumption.