Thermal Storage Air Handling for Data Center Free Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Data centers face high operational costs and environmental impact due to energy-intensive mechanical cooling systems and limitations of evaporative and free-cooling methods in high humidity environments, where relative humidity constraints hinder effective heat removal and can cause damage to computer systems.

Innovation Solution

An air handling system incorporating a thermal storage unit with phase change materials that adjusts thermal energy absorption and release based on ambient conditions, reducing relative humidity and maintaining temperature and humidity thresholds for efficient cooling of heat-producing components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical chillers are used for cooling, then temperature control is reliable, but energy consumption and operational costs increase substantially

Engineering Contradiction:
Improvetemperature control reliabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system pre-cools air during nighttime when ambient temperatures are lower, storing this cooled air in a thermal storage unit. During daytime when cooling demand is high, the stored cold air is released to supplement mechanical chiller operation, reducing overall energy consumption while maintaining reliable temperature control

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cooling system operates in periodic cycles, alternating between free-cooling mode (when ambient conditions permit) and mechanical chiller mode (when temperature thresholds are exceeded). This periodic operation reduces energy consumption by minimizing mechanical chiller runtime while ensuring temperature reliability

Inventive Principle:
Principle #19Periodic action

2Use of energy by moving object

If evaporative cooling or free-cooling is used, then energy consumption is reduced, but relative humidity exceeds upper thresholds causing system malfunction

Engineering Contradiction:
Improveenergy consumptionVSAvoidsystem operational reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system changes the temperature parameter of incoming air by pre-cooling it in the thermal storage unit before it enters the data center. This temperature reduction decreases the air's humidity ratio, allowing free-cooling operation even in high ambient humidity conditions while maintaining relative humidity below critical thresholds

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The thermal storage unit acts as an intermediary between the ambient environment and the data center cooling system. It conditions the ambient air by removing excess heat and moisture, delivering pre-conditioned air that enables reliable free-cooling operation without directly exposing the data center equipment to unconditioned high-humidity air

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If free-cooling is used in high humidity environments, then operational costs are reduced, but water vapor condensation damages computer systems

Engineering Contradiction:
Improveoperational costVSAvoidwater vapor condensation
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The system preliminarily conditions ambient air by cooling it below its dew point in the thermal storage unit, causing water vapor to condense and be removed from the air before it enters the data center. This preliminary dehumidification prevents condensation on computer systems while enabling free-cooling operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system extracts water vapor from the ambient air stream by cooling the air in the thermal storage unit to a temperature where condensation occurs. The condensed water is separated and removed, delivering dehumidified air to the data center that prevents equipment damage while maintaining low operational costs

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively cools data center components by condensing water vapor and adjusting humidity levels, allowing for operation within acceptable temperature and humidity ranges, reducing energy consumption and environmental impact while maintaining system integrity.

Implementation Method 1

the thermal storage unit is configured to remove thermal energy from air passing across the thermal storage unit, thereby condensing water vapor in the air and reducing a dew point temperature of the air

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 2

under another set of ambient air conditions, the thermal storage unit is configured to release the previously removed thermal energy into air passing across the thermal storage unit

Methodology Applied
Scientific EffectThermal energy release: Conduction (thermal)

Implementation Method 3

a thermal storage unit may include a phase change material such as a paraffin wax, salt solution, an inorganic phase change material, or other suitable material with a high heat of fusion. The phase change material may melt (i.e. change from a solid phase to a liquid phase) when air passes across the thermal storage unit under a given set of ambient air conditions

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 4

The phase change material may subsequently solidify (and therefore recharge) when air passes across the thermal storage unit under another set of ambient air conditions. The solidifying of the phase change material may result in thermal energy being released into the air

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3430876B1Free cooling in high humidity environments
Publication Date: 2021.06.30 AMAZON TECH INC
  • EP3430876B1 patent drawingFigure 1A~1B
  • EP3430876B1 patent drawingFigure 2A~2D
  • EP3430876B1 patent drawingFigure 3

AI summary

A data center includes heat producing components and an air handling system that provides reduced relative humidity air to cool the heat producing components. The air handling system includes a thermal storage unit that removes thermal energy from incoming air under a given set of ambient air conditions and releases thermal energy into incoming air under another set of ambient air conditions. Under the given set of ambient air conditions, the thermal storage unit cools the incoming air and causes water vapor to condense out of the incoming air. Under the other set of ambient air conditions, the thermal storage unit releases thermal energy into the incoming air, thus heating the incoming air.