Temperature chaining
The premise is that every system in a datacentre can be equipped with a shared water infrastructure which is divided into multiple stages with different temperatures.
Temperature or energy chaining is applied in heating systems where hydraulic designs allow for return loops and serial heaters.
When liquid penetrates the IT space, internal fans are reduced or completely eliminated which saves energy.
The advantage of the active rear doors is that all the heat from air cooled IT is immediately absorbed by the water circuit when it leaves the rack which eliminates the need for CRACs, also in partial ILC implementations.
For example, storage environments are least suitable to be cooled directly by liquid due to the low energy production and the common dependency on moving parts.
High volumes of servers which require the least maintenance can best be positioned in a Total Liquid Cooling environment.
Varying specialised server systems which require constant physical access are best situated in Direct Liquid Cooled environments.
Therefore, different technologies can be set up in an optimised order of tolerance to allow a multi-step increase in temperature within the cooling circuit.
By chaining the segmented liquid circuits in larger environments, very high return temperatures can be achieved, which enables the practical and effective reusability of thermal energy and decreases investments needed to make large scale heat reuse a viable option.
A major advantage of this strategy is the fact that temperature differences (dT) within a cooling circuit can be drastically increased.
This results in a complete lack of cooling installations and the datacentre effectively acts like a large water heater.
The ILC racks in this setup effectively function as air handlers which maintain the entire room temperature and absorb all thermal energy leakage from the DLC and TLC environments.
In smaller footprints, temperature chaining can be achieved by creating a small water circuit with a mixing valve and buffer tank.
The advantage of this approach is the compatibility with variable input temperatures which are common with dry cooling installations.
