Cooling Systems — Topic Hub

A curated navigational hub for data center cooling systems: air-side economisation, chilled-water plants, direct liquid cooling (DLC), free-cooling strategies, and PUE optimisation. This page aggregates articles, calculators, and standards references — it performs no calculation of its own.

Type Navigation Hub Domain Cooling Systems Engine None — reference only

▶ Open Cooling Systems Hub

01 Purpose & scope

This hub consolidates the cooling discipline of data center infrastructure engineering. It covers the full spectrum of heat-rejection strategies — from legacy raised-floor CRAC/CRAH arrangements through chilled-water primary/secondary loops and modern direct liquid cooling (DLC) to facility-level free-cooling and economiser cycles. The scope includes thermal envelope design, PUE decomposition by cooling contribution, and ASHRAE-envelope compliance for IT equipment inlet temperatures.

Cooling is the primary lever for PUE reduction in hyperscale and edge deployments. The hub links to worked-example calculators, comparative analyses, and detailed technical articles covering design tradeoffs.

02 What this hub links to

Chiller Plant Calculator — COP, capacity, primary/secondary loop sizing, wet-bulb approach
Water System Calculator — cooling tower make-up water, WUE, blowdown, drift losses
PUE Calculator — live PUE/DPPE decomposition: IT / cooling / power / lighting shares
Air vs Liquid Cooling Comparison — side-by-side TCO and PUE impact analysis
Chiller Plant Methodology Manual — full equation set behind the chiller calculator
Water System Methodology Manual — WUE / make-up / blowdown equations and constants
PUE Methodology Manual — Green Grid PUE definitions, DCiE, DPPE
DC Solutions Hub — broader data center design topic index

No calculation engine on this page. This is a curated navigation hub — it aggregates articles and tools; it performs no calculation. For calculation methodology, see the linked calculator manuals above.

03 References & standards

ASHRAE TC 9.9 (2021) — Thermal Guidelines for Data Processing Environments: A1–A4 / B / C / D class inlet-temperature envelopes; recommended (18–27 °C) vs allowable ranges.
ASHRAE 90.4-2022 — Energy Standard for Data Centers: mechanical load component (MLC) / electrical loss component (ELC) targets by climate zone.
The Green Grid WP#49 — PUE / DCiE / DPPE definitions and measurement tiers (IT-measured, facility-measured, source-energy).
ISO 30134 series — Data center key performance indicators: KPI 1 (PUE), KPI 2 (REF), KPI 5 (WUE), KPI 8 (CUE).
EN 50600-4-1/4-2 — Data center performance metrics: energy efficiency, renewable energy factor.
CIBSE TM65 — Embodied carbon in building services equipment; applicable to CRAC/CRAH/chiller selection.
AHRI 550/590 — Performance rating of water-chilling and heat pump water-heating packages.