The Alphacool ES reservoir for DDC pumps is specially designed for 1U server racks. The reservoir is extremely compact and integrated pump top for the DDC pump allows for extremely high pump performance. The large reservoir is more than sufficient for a liquid cooling loop in a 1U server rack.

How Can I Connect the Reservoir?
The reservoir offers a total of seven G1/4" connections, 1x OUT and 6x IN. The connection possibilities are distributed on all sides. One IN is located on each side. Additionally, there are two IN on the top side which are mainly used for filling. One IN can be used directly for filling, while the second IN is used to allow air to escape more easily during the process. Due to the many connection possibilities, various mounting options are possible.

What Mounting Options Does the Expansion Tank Offer?
There are mounting holes on the sides that allow mounting in the standard 2.5-inch hard drive space. If no corresponding space is available for mounting, a Velcro strip is also included. Both parts of the Velcro have a self-adhesive surface that allows you to attach one part to the enclosure and one part to the storage bin. The mounting is ready and can also be easily removed if necessary.

Direct Radiator Mounting Is Possible!
The scope of delivery includes a double nipple fitting with which allows the reservoir to be screwed directly to a radiator of the Alphacool NexXxoS series. For 1U housings Alphacool offers special 40 mm radiators from the NexXxoS X-Flow series. With these radiators, the reservoir can be mounted via the double nipple on the side or in front of the radiator. This saves a lot of space instead of connecting the reservoir with a longer hose.

Installation of the Pump
The installation of the DDC pump is very easy. The O-ring is put on and then the pump is placed into the pump top and fixed with four screws. Please note that a DDC version with the original Laing pump housing is installed. Other pump housings may be larger and may not fit the reservoir.


The Alphacool ES Reservoir 1U - DDC version is an extremely compact expansion tank especially for 1U server racks with extensive connection and mounting options.

Note on application
Please use only in conjunction with clear transparent water cooling fluids. The particles and additives in Pastel liquids can clog and permanently damage water cooling products such as radiators, pumps, coolers and hoses. This can result in voiding the manufacturer's warranty as well.

Technical data