Process Cooling and Data Centres
A data centre is a large facility that houses many computer servers and other associated hardware and networking equipment. Its primary purpose is to store, manage, process, and distribute large amounts of data.
Data centres are designed to provide high levels of reliability, availability, and security for the information technology (IT) infrastructure of organisations. They typically feature redundant power and cooling systems, backup generators, fire suppression systems, and physical security measures to ensure uninterrupted operation and protection of the equipment housed inside.
Data centres play a critical role in the functioning of modern businesses and organisations, as they enable the storage and processing of vast amounts of data that are used to support critical business processes, applications, and services. They are used by a wide range of organisations, including businesses, government agencies, universities, and research institutions.
What is the Optimum Temperature for Data Centres?
The optimum temperature for data centres is generally considered to be between 18 and 27 degrees Celsius (64 and 80 degrees Fahrenheit).
However, the specific optimal temperature range for a data centre may depend on several factors, such as the type of equipment being used, the density of the equipment, and the location of the data centre. Some newer equipment can tolerate higher temperatures, and some organisations may choose to operate their data centres at higher temperatures to save on cooling costs.
It is also important to note that maintaining a consistent temperature level is critical for data centre performance and reliability. Sudden changes in temperature can cause hardware failures or data loss. Therefore, data centre operators typically employ sophisticated cooling control systems to ensure a stable and controlled environment for their equipment.
The top operating temperature for data centres can vary depending on factors such as equipment specifications, cooling capabilities, and environmental conditions. However, the generally accepted upper limit for data centre operating temperatures is around 40 degrees Celsius (104 degrees Fahrenheit). While it is technically possible to operate data centres at such elevated temperatures, it requires careful planning and implementation to ensure the reliability and performance of the equipment. Some key considerations include:
Why do Data Centres Need Process Cooling Equipment?
Data centres generate a significant amount of heat due to the large number of servers and other computing equipment that are housed in a relatively small space. The heat generated by the equipment can cause damage to the hardware and lead to system failures if not properly managed.
Process cooling equipment is necessary to maintain a stable temperature and humidity level within the data centre. This helps to prevent equipment overheating, which can cause system downtime and data loss. Cooling systems also help to improve the efficiency of the equipment, as many servers and other computing devices are designed to operate within a specific temperature range.
There are various types of process cooling equipment that can be used in data centres, including air-based cooling systems, liquid-based cooling systems, and hybrid systems that use both air and liquid cooling. These systems may include components such as chillers, pumps, cooling towers, heat exchangers, and fans, among others.
Air Cooling or Water Cooling?
Deciding between liquid or air cooling in data centres depends on several factors, including the specific needs and requirements of the data centre, the equipment being used, and the availability of resources such as water and energy.
Air cooling is a simpler and more traditional method of cooling, where cool air is circulated through the data centre to remove heat from the equipment. Air cooling systems are generally less expensive to install and operate than liquid cooling systems, and they require less maintenance. They are also a good choice for data centres with lower power densities and less heat-generating equipment.
Liquid cooling is a more complex and specialised method of cooling, where a liquid heat transfer fluid is circulated through the data centre to remove heat from the equipment. Liquid cooling systems are more expensive to install and operate than air cooling systems, and they require more maintenance. However, there has been a move towards liquid cooling in data centres in recent years for several reasons:
Immersion Cooling
Recirculating chillers can be used in immersion cooling systems to remove heat from the liquid heat transfer fluid that is used to directly cool the IT equipment.
In an immersion cooling system, the IT equipment (such as servers or GPUs) is submerged in a non-conductive heat transfer fluid that directly absorbs the heat generated by the equipment. The heat transfer fluid then flows through a closed loop system to a heat exchanger, where the heat is transferred to a primary water circuit that is circulated to a recirculating chiller.
The recirculating chiller cools the heat transfer fluid within the primary water circuit to a specific temperature and circulates it back to the heat exchanger, where it removes the heat from the heat transfer fluid in the immersion cooling system. The fluid within the primary water circuit is then recirculated back to the chiller for further cooling.
The use of a recirculating chiller in an immersion cooling system provides several benefits. It allows for precise temperature control of the secondary coolant, which can improve the efficiency of the cooling system. It also allows for the use of high-density IT equipment that generates a significant amount of heat, as immersion cooling can provide more efficient cooling than traditional air- or water-cooling methods.
Rack Mounted Solutions
Rack mounted chillers are recirculating chillers that are designed to be mounted directly onto a server rack in a data centre. They are used to provide localised cooling to high-density IT equipment, such as servers, storage systems, and networking devices.
Rack mountable chillers are typically compact and lightweight, with a slim profile that allows them to fit seamlessly into a server rack. They are designed to provide efficient and reliable cooling to IT equipment, with precise temperature control and a low noise level.
One of the main advantages of rack mounted chillers, is that they provide localised cooling to the IT equipment, which can help to reduce the overall cooling load of the data centre. This can result in improved energy efficiency and lower operating costs.
Rack mountable chillers can be designed with a variety of features and options to meet the specific cooling requirements of the data centre. For example, Applied Thermal Control have a variety of cooling capacities, ranging from 0.5kW to 1.9kW depending on the size and density of the IT equipment.
They may also have advanced control systems that can monitor and adjust the coolant temperature, flow rate, and other parameters to optimise performance and reduce energy consumption.
Direct-to-Chip Cooling
Recirculating chillers can be used in chip cooling by circulating a heat transfer fluid (such as water or a water-glycol mixture) through a closed-loop cooling system to remove heat from the chip.
The chiller cools the heat transfer fluid to a specific temperature and circulates it through the cooling system. The heat transfer fluid absorbs heat from the chip and carries it back to the chiller, where it is cooled and recirculated back to the chip.
The cooling system can be designed in several ways, depending on the specific application and requirements. In some cases, the heat transfer fluid may be circulated directly through the chip or the heat sink. In other cases, a cold plate may be used to transfer heat from the chip to the coolant.
Recirculating chillers can be particularly effective for cooling high-performance computing clusters and other high-density chips that generate a significant amount of heat. They can also be used in applications where a precise and stable heat transfer fluid temperature is required, such as in medical equipment or research facilities.
In addition to chip cooling, recirculating chillers can also be used for other cooling applications in the data centre, such as the cooling of servers, storage systems, and other equipment. They can be designed to be energy-efficient and environmentally sustainable, using technologies such as variable-speed compressors and renewable energy sources like solar or geothermal power.
Passive Cooling in Data Centres
Passive cooling is an approach to cooling data centres that relies on natural or low-energy methods to dissipate heat without the use of mechanical equipment such as fans or pumps. It aims to minimise or eliminate the need for active cooling systems, reducing energy consumption and operational costs. Here are some common techniques used in passive cooling for data centres:
Heat Transfer Fluids Used in Data Centres
Recirculating chillers in data centres are typically used with heat transfer fluids to provide efficient and effective cooling. The heat transfer fluid is circulated through a closed loop system to remove heat from the equipment and carry it back to the chiller for cooling.
When making a decision, it is essential to evaluate specific data centre requirements, such as temperature ranges, equipment compatibility, safety concerns, and budget constraints. Additionally, factors like cooling efficiency, maintenance needs, environmental impact, and overall system reliability should be considered.
Ultimately, selecting the most suitable heat transfer fluid involves finding the right balance between performance, cost, safety, and environmental considerations. Consulting with experts and conducting thorough evaluations will help ensure an optimal heat transfer fluid choice for data centre cooling systems, promoting efficiency, reliability, and sustainability.
There are several types of heat transfer fluids that can be used with recirculating chillers in data centres, depending on the specific application and requirements. Some of the commonly used heat transfer fluids include:
