Alphacool ES Reservoir 1U - DDC Version [15377]

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?
On the bottom and on the sides, there are mounting holes that allow you to mount in the standard 2.5" hard disk space. As with a 2.5" SSD, the reservoir can be screwed to the bottom or the sides. If there is no corresponding mounting space available, a Velcro pad is also included. Both parts of the Velcro tape have an adhesive surface allowing you to attach one part to the case and one part to the reservoir and then simply sticking them together. The assembly is finished and it is also easily removed if needed.

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.

Technical data

• W x D x H: 67.9 x 100.2 x 40 mm
• Net weight: 73 g
• Maximum working temperature: 60 °C
• Connections: 7 x G1/4"
• Pressure tested: 0,8 Bar