Coolants and Loop Chemistry
Data Center
Coolants and loop chemistry cover everything that circulates in the liquid loop of a data centre or keeps it serviceable: the heat transfer fluid itself, its inhibitor package, agents against microbial growth, cleaners for commissioning and the instruments used to assess the condition of the loop. The common approach in an IT loop is a mixture of deionised water and propylene glycol at a glycol content of around 25 percent. It protects outdoor piping and dry coolers against freezing without loading heat transfer as heavily as higher concentrations do.
Two things decide how long a fill lasts: the inhibitor package that maintains the passive layers of the installed materials, and regular sampling, which reveals inhibitor depletion, pH drift or early microbial growth before damage occurs. This section is currently being built up: the subcategories describe the function each group has in the cooling loop, articles are not listed yet. On material compatibility and miscibility we can advise already now.
Categories
Materials in the water-glycol loop of a data centre - suitability and limits
| Material | Suitability in the IT loop | Note |
|---|---|---|
| Stainless steel | unrestricted | standard for pipe, valve and fitting |
| PVDF, PP, PE, PTFE | unrestricted | hose, fitting and housing parts |
| POM, PVC | unrestricted | moulded parts and side stream components |
| Brass, red brass, bronze, copper | only with single-material pairing | avoid contact with other metals in the same loop |
| Galvanised steel | not permitted | zinc dissolves in a glycol loop and enters the fill |
| Aluminium | not permitted | cannot be controlled long term in a mixed loop with stainless steel and copper alloys |
- Initial fill of new direct-to-chip cooling loops
- Topping up and reconcentrating existing fills
- Flushing and cleaning before commissioning
- Recurring condition checks during operation
- Dry coolers and outdoor piping exposed to frost