3 min read

FAQs on Adiabatic Cooling in a Data Centre

Adiabatic cooling is one of the most efficient ways of cooling a data centre, saving everyone money (other than the energy company - see answer 2 below) and helping the environment, but what does adiabatic mean?

I caught up with Ash, our Data Centre Facilities Manager at 4D, to ask some questions about what adiabatic cooling is and why data centres use it.

Computers generate heat, and for the same reason your laptop has a fan, data centres need cooling infrastructure to avoid damage to hardware. However, due to the scale at which data centres operate, their cooling infrastructure uses advanced technologies to be able to handle the heat-load of a data floor full of servers.

Adiabatic cooling tower at a data centre

1. What is adiabatic cooling?

Adiabatic cooling uses a natural phenomenon to initiate cooling through evaporation. You know how sweating cools us down, or how you feel cold when you get out of the swimming pool? That’s down to the adiabatic process. The evaporation of water from your skin creates a cooling effect, bringing down your temperature. Adiabatic cooling works in the same way, using evaporation to create a cooling effect that can be used to cool air or water.

In our data centre we use two cooling loops:

  • The first loop constantly circulates through the cooling tower where water is regularly piped in to carry heat away from the second loop.
  • This second loop is completely sealed and circulates through the data centre in stainless steel pipes. It passes through the air handling units and rear door coolers and then goes back to the cooling towers where it meets a heat exchanger.
  • At the heat exchanger the heat is transferred from the water in the pipes to the water in the cooling tower, where the adiabatic process sends it out to the atmosphere.
  • Crucially, the two water loops never meet – it’s only heat that moves from one loop to the other. This keeps the data centre system cool and contaminant-free.

2. How does is it compare to conventional air cooling?

Adiabatic cooling is highly energy efficient. Unlike conventional cooling systems, it doesn’t require an energy-intensive compressor to achieve cooling. The only power that is needed is for the fan that assists the adiabatic process in the cooling tower and the pumps that move the water around. So you get clean, efficient cooling at a fraction of the cost of conventional air cooling systems.

If you want to take advantage of efficient cooling to reduce costs and your environmental impact, a lift-and-shift migration is a straightforward way to migrate your IT into a data centre which you can learn all about from our 'Migration Checklist'.

3. Does adiabatic cooling increase the risk of legionella?

Legionella is a risk where water mists. We’ve designed our cooling towers to pour rather than mist, so that risk is drastically reduced – and we also use an automated chemical dosing system to inhibit the growth of bacteria. In addition, we undertake manual checks on a weekly, monthly, quarterly, half-yearly and annual basis. We’re not taking any chances!

Adiabatic or evaporation cooling tower

4D's adiabatic cooling towers make us one of the most energy efficient data centres in the country

4. How do you avoid contamination?

Older style adiabatic cooling systems just blow (filtered) outside air directly into the data centre, but this risks contamination from the outside environment. Dust and pollen could wreak havoc with your equipment, which is why we came up with the second loop system. There’s no chance for contamination because the cooling water is completely sealed in stainless steel pipes.

5. Is it safe around electrical equipment?

Absolutely. Apart from the fact the pipes are stainless steel and were built to last, we made sure they were pressure-tested when they went in – at pressures way beyond those we would ever use here. And we have an automated leak detection system, which would give us advanced warning if ever there was a problem. We also have a backup air conditioning system just in case we do ever need to shut down the adiabatic cooling system for maintenance.

6. What are the benefits of adiabatic cooling?

The main benefits of our adiabatic cooling system are that it’s energy efficient and it’s clean. We pay much less to run this system compared to a conventional cooling system, which gives us cost savings we can pass on to our customers. And it’s better for the environment, which is important to us. At our Surrey data centre we have a PUE (Power Usage Effectiveness) of 1.12, making us one of the greenest data centres in the UK.

The closed-loop cooling system also guarantees we’re not bringing any contaminants to the data floor, which ensures the safety and health of your equipment.

Moving your IT to a data centre

As well as cooling, data centres provide advanced infrastructure to protect your IT's power and network connectivity. At 4D, we're also really proud of our expert engineers who work as an extension of your in-house IT team, taking care of your hardware and freeing up your team to focus on other business-critical projects. So if you want to reduce your system downtime and save costs, moving into a data centre is the easiest way to upgrade your infrastructure.

4D operates award-winning, UK-based data centres, and we have achieved industry-leading efficiency thanks to our adiabatic cooling towers, if that sounds like a good hosting environment for your IT, then get in touch.

About our contributor


Man with glasses in grey jumper circle photo

Ash Rance has been 4D's Data Centre Facilities Manager since 2018. He brought with him a wealth of experience from a long career working with managed infrastructure and data centres. At 4D he has helped to, quite literally, keep the lights on and has expertly managed our specialist environments helping us achieve our excellent performance record.


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