Mattress assemblies including phase change materials and processes to dissipate thermal load associated with the phase change materials
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Solution Overview
Problem
High thermal mass mattress assemblies with phase change materials experience prolonged thermal loading that overlaps with subsequent sleep cycles, reducing the effectiveness and consistency of thermal performance.
Innovation Solution
Incorporation of a spacer layer with a pump system that provides positive or negative air flow to dissipate thermal load during non-use periods, utilizing a conduit for fluid communication with foam layers containing phase change materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If phase change materials are used in mattress assemblies to absorb body heat, then cooling sensation and thermal comfort are improved, but thermal load retention overlaps with subsequent sleep cycles reducing effectiveness
Solution Approach 1:
The pump system is activated during non-use periods (daytime) to proactively dissipate thermal load from the phase change materials before the next sleep cycle begins. This preliminary action ensures the PCMs are reset to their initial state, preventing overlap with subsequent sleep cycles and maintaining consistent cooling performance.
Solution Approach 2:
The mattress assembly implements periodic thermal management by alternating between heat absorption during sleep cycles and active heat dissipation during non-use periods. The pump operates intermittently based on thermal sensor feedback, creating a cyclical pattern that matches the usage pattern and maintains optimal thermal performance across multiple sleep cycles.
2Quantity of substance
If high thermal mass materials are used to store heat, then thermal energy storage capacity is improved, but heat dissipation time is prolonged causing overlap with next sleep cycle
Solution Approach 1:
The pump system uses pneumatic principles to force air through the spacer layer and across the phase change material surfaces during non-use periods. This active air flow dramatically accelerates heat dissipation compared to passive convection, reducing the heat dissipation time from hours to minutes while preserving the high thermal mass capacity for heat storage during sleep cycles.
Solution Approach 2:
The spacer layer is designed with high porosity to enable rapid air flow through the mattress assembly during pump operation. This porous structure allows efficient heat transfer from the phase change materials to the moving air while maintaining the thermal mass properties of the PCMs, resolving the contradiction between storage capacity and dissipation speed.
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
Ensures consistent thermal performance from one sleep cycle to the next by effectively dissipating retained heat, maintaining the effectiveness of phase change materials.
Implementation Method 1
a pump comprising a conduit, wherein the conduit is in fluid communication with the spacer layer, and wherein the pump is configured to provide positive air flow or negative air flow into the air permeable layer to dissipate a thermal load associated with the phase change material
Implementation Method 2
Phase change is a term used to describe a reversible process in which a solid turns into a liquid or a gas. The process of phase change from a solid to a liquid requires energy to be absorbed by the solid. When a phase change material ("PCM") liquefies, energy is absorbed from the immediate environment as it changes from the solid to the liquid.
Implementation Method 3
a phase change material absorbs and releases a large quantity of energy in the vicinity of its melting/freezing point. Therefore, a PCM that melts below body temperature would feel cool as it absorbs heat, for example, from a body.
Implementation Method 4
Phase change materials, therefore, include materials that liquefy (melt) to absorb heat and solidify (freeze) to release heat.
Implementation Method 5
the PCM will slowly release that heat to maintain body temperature
Data Source
AI summary
Mattress assemblies including phase change materials and processes for dissipating retained in the mattress assemblies generally include a spacer layer in proximity to one or more foam layers containing a phase change material; and a pump in fluid communication with the spacer layer to provide a positive or negative air flow into the spacer layer to reduce retained heat in the phase change materials subsequent to a sleep cycle. The process includes operating the pump between sleep cycles to reduce the retained heat.