Data center cooling: waste heat put to good use
Thermally driven recirculation cooling for data centres – Adconair AdiabaticDXcarbonfree
High power requirements from data centres are posing more and more new challenges for building owners and operators. Data centres must not only function reliably, but also be energy efficient. With the thermally driven Adconair AdiabaticDXcarbonfree system, the electrical energy required to cool the servers can be kept especially low, as heat is used instead of electricity. Otherwise unused heat, e.g. from industrial processes, district heating or waste heat from combined heat and power plants, can therefore be put to good use, are cost-effective and sustainable in cooling the data center.
Our “data footprint” is also becoming our “carbon footprint”. Data transfer – whether it is Google search, online shopping on the Walmart or watching the Netflix series – it warms up the atmosphere through data centers, which are also known as »energy monsters« that needs an enormous amount of cooling energy to operate.
Efficient data center cooling: ADCONAIR ADIABATIC DXcarbonfree
- Conventional synthetic refrigerants are not used
- Climate-neutral cooling technology combined with adiabatic evaporative cooling
- Integrated adsorption cooling circuit without movable components and therefore easy to maintain
- Air temperatures supplied can be as low as 20-25 °C, even at very high exhaust temperatures from the hot aisles
- All-in-one solution, all components integrated in one air handling unit (AHU)
- Intelligent, integrated control and regulation
How the adsorption cooling unit works
At the heart of the system lay two modules which are equipped with silica gel as an adsorption material. The physical process of adsorption generates cold water, which is used in a cooling coil for sensible cooling of the recirculating air. The flow temperatures from the refrigeration circuit, combined with indirect, adiabatic evaporative cooling, are low enough to cool the exhaust air from the hot aisle from 35 to about 20 °C. While one module is generating the cold water using this process, the second module is being regenerated. For the desorption of the saturated silica gel to take place it is supplied with hot water at 55 °C. The desorption process is at least as fast as adsorption, so there is always enough cooling power available.
The following diagram shows this process:
Waste heat put to good use – adiabatic cooling
As an additional alternative to the electrically driven variant of the AdiabaticDXcarbonfree cooling technology, Menerga has developed a thermally driven version in cooperation with a partner. The primary aim is to avoid high electrical power consumption in the summer cooling season. The term „carbonfree“ describes adiabatic evaporation cooling, which is supported by a cooling system operated with a refrigerant free of F-gas.
Cooling is provided using a closed adsorption refrigeration circuit fully integrated into the air handling unit. This system supplies the cooling coil with cold water to cool the recirculating air. Unlike a compression refrigeration system, no electricity is required to drive this. Instead, heat is used at a temperature of around 55 °C derived from systems such as solar thermal energy, district heating or waste heat from combined heat and power plants or emergency generators. The recooling of the adsorption cooling circuit, which is also integrated into the air handling unit, ensures very low recooling temperatures even in midsummer; Thereby enabling high cooling performance figures. Furthermore, the water refrigerant used (R718) has a Global Warming Potential (GWP) of 0 and therefore has no direct greenhouse potential. Unlike other natural refrigerants, it is also non-flammable and non-toxic.