Facility Water System (FWS)
Data Center
The facility water system (FWS) is the outer loop of a data centre cooling installation. It picks up the heat of the inner loop, the technology cooling system, across a heat exchanger and rejects it to the surroundings. Dry coolers and free cooling modules, pump sets, buffer tanks and hydraulic separators, and the treatment of the circulating water all belong to this loop. The medium is water or a water-glycol mixture, and the glycol content drives both the required flow rate and the choice of wetted materials. This section describes what each assembly does in the loop; the matching range is currently being built up.
No articles are listed in this branch at present. The subcategories are already in place so that the intended scope of the facility loop is visible, together with the gaps that still exist today. Until the range is published, the sections below set out the selection criteria: the task each assembly performs in the loop, which materials hold up in a data centre water-glycol circuit, and what to watch for when components of different metals are combined.
Categories
Function and selection criteria per assembly
| Assembly | Function in the cooling loop | What matters when selecting |
|---|---|---|
| Dry coolers and free cooling modules | Reject the heat of the loop to ambient air and replace mechanical cooling as soon as the outdoor temperature is low enough | Capacity at the design point, air flow and sound level, wetted material, glycol content of the medium |
| Buffer tanks and hydraulic separators | Provide water volume in the loop and decouple the source side from the load side hydraulically | Storage volume, connection size and port arrangement, insulation, shell material |
| Water treatment, softening, demineralisation | Condition fill and make-up water and keep hardness, dissolved salts and particles out of the loop | Raw water quality on site, loop volume, process (filtration, softening, demineralisation), monitoring of water values |
- Data centres with air-cooled dry coolers and year-round free cooling
- Colocation floors with strictly separated facility and IT loops
- Retrofitting a free cooling branch onto existing chillers
- Edge sites with compact outdoor heat rejection
- Installations running water-glycol where frost protection is required outdoors
- Refurbishment of older loops in which galvanised or mixed-metal sections are replaced