With the amount of computing equipment present, data centres produce a lot of residual heat. Without a comprehensive strategy to keep data centre rooms cool, facilities run the risk of equipment overheating, which could lead to failures and downtime. As data centres pride themselves on their ability to remain accessible 24/7, cooling is a crucial part of digital infrastructure.
Of course, cooling solutions require power to run, which brings further considerations around energy efficiency and cost into play. Many data centre operators are looking toward the latest in passive and liquid cooling technology to stay ahead of the curve when it comes to energy efficiency in cooling their facilities.
Digital Infra Network spoke with Vijay Madlani and Karthik Velayutham from Katrick Technologies about their latest passive cooling innovation.
Can you tell me a bit about how your passive cooling system works?
Sure. So, our TVB cooling technology uses mechanical vibrations to remove heat from the system passively. The way it works is we have a chamber filled with bi-fluids of different densities and thermal properties, and when heat enters the chamber, a phase change occurs with one of the fluids, which then interacts with a second fluid to create a dynamic movement between them, converting the thermal energy into fluid vibrations.
Then, an array of protruding internal and external heat fins captures these vibrations and converts them into random mechanical vibrations. The resultant effect oscillates the fins to passively dissipate the unwanted heat by moving ambient air around it.
I suppose it is a bit outside-the-box because normally data centres want to improve the mechanical efficiency of the system, rather than lose mechanical energy. But, in this instance, those mechanical losses are leading to a much-improved rate of heat rejection. Based on our calculations, we believe that a TVB passive cooling system can save over 50 per cent of the cooling power requirements per annum in the Northern hemisphere.
Just to confirm, this is a unique system to Katrick?
Capturing heat and converting it into mechanical vibrations for cooling has never been done before, no. We were actually working on heat engines using mechanical vibrations, when we stumbled upon the idea of utilising the technology at data centres because one of the byproducts on the heat engine is that it actually removes the heat.
What kind of data centre facility is TVB cooling technology suitable for?
I will give you an example. We are working with a PLC data centre provider called Iomart, which is where we did our first prototype trial for COP, which has been very successful. We have also recently been working with one of the largest banks in the world to see whether the technology could be utilised at their facilities. So, I think that shows the scale of potential applications – from a data centre provider to a large server provider for banks, the system is applicable across the board, at any facility which wants to remove adverse heat.
Data centres in the Northern hemisphere, particularly in countries with cooler climates such as Norway and Sweden, are able to use free cooling, whereas it is much more difficult for a facility in Saudi Arabia to have access to free cooling. How does your technology work in different climates?
The data centre we visited recently in Scandinavia is testing three different options. One of those options is free cooling. Bear in mind that, with free cooling, it is not just a case of letting air in; the air has to go through a filtration and dehumidifier system, which takes up a lot of space because the fans they use for that are enormous. So, if we were to compare that with our system, it is pretty much the same amount of energy usage. But, obviously, sometimes the temperature will increase and a data centre reliant on free cooling will have to use more power for a more traditional cooling technology.
I suppose the biggest advantage we have in Scandinavian countries is that our technology utilises DHT to enhance the cooling effect. There are probably some new regulations coming in soon which means that data centres will need to utilise waste heat, so we are already ahead of the curve in that respect.
Then, if we go to other countries in the same hemisphere – Germany, or the UK – our technology will have an even greater advantage when you compare it to free cooling because of the more temperate climates.
In places like Hong Kong and the Middle East, as you said, free cooling just is not possible, and they have to use conventional cooling systems. The temperature will not always be upwards of 40 degrees though, it will fluctuate, so if it sits around 30 to 35 degrees, we can really compare with the conventional system and save around 30 per cent of cooling power requirements. In the UK though, that is more like 70 per cent, and it is between 75 to 80 per cent in Norway.
Can your technology work alongside district heating participation?
No, our technology just rejects the heat. The thermal energy that comes from a data centre is very low quality, and, if we tried to utilise that heat and convert that to electricity, the thermal efficiency would also be very low.
We went to a data centre yesterday, actually, and, on average, they are using about two megawatts of energy for cooling. If we were to use our system, that would drop to between 400 and 500 kilowatts, so that is a massive difference in terms of power usage. If we captured that heat and tried to produce power instead, we would probably only produce 40 or 50 kilowatts, and the cooling effect will be drastically reduced. So, that is why we decided that trying to produce energy is not very efficient, compared to actually just rejecting the heat.
What are the costs associated with implementing this kind of passive cooling system? Is it easier for it to be deployed at a new build, or is it just as easy to retrofit it to an existing build?
In terms of a new data centre, it is very straightforward. In the design phase, the footprint for their condensers will be practically the same, but the height will probably need to increase compared to a typical data centre building to fit the cooling structure in place.
We can also provide solutions to retrofit data centres, but obviously, there are extra considerations in terms of space for smaller, inner-city builds.
Could you tell me about the liquids you use? How sustainable are they?
Even though the fluids we use are termed as ‘refrigerants’, they have zero ozone-depleting potential, they are non-toxic, non-flammable, and non-reactive. They pretty much like water, to be honest. There is a reason we are very specific about the types of fluid we use, and we are very keen the ensure that the fluids we use to meet these criteria and are as sustainable and environmentally friendly as possible.
We are speaking with some global manufacturers of these fluids, who are trying to create fluids with these properties at a cheaper rate. That would definitely make the technology even more accessible for operators interested in increasing their energy efficiency via passive cooling.
There is a lot of buzz around liquid and immersion cooling as the future of data centre cooling, in terms of providing energy efficiency. Where do you see your passive cooling system fitting into that?
I think, in five years or so, the size of the transistor will get smaller, there will be an increase in demand for capacity, and the residual heat coming from all these servers will just get higher and higher. Eventually, we will get to the point where standard cooling systems will not be able to cool facilities efficiently using just air. I am sure that, in the future, the industry will move towards immersion cooling ducts. Our patented design means that, when that shift happens, we are able to adapt straight away.
From a cost perspective, if you look at the sector as a whole, which is going to grow at a very aggressive rate over the coming years, our technology has the potential to save up to 25 per cent of the total operating costs that a facility faces. That 25 per cent that has been saved can then be used elsewhere to grow the business without any extra capital. That, I think, is a great selling point for encouraging businesses to think about implementing technology which can increase energy efficiency and savings.