# Temperature Variations in a Flexible Thermoelectric Module with an Evaporative Heat Sink

## TL;DR

This paper studies how a thermoelectric module with an evaporative heat sink can cool a simulated skin model, showing modest temperature reductions that may not be sufficient for long-term use.

## Contribution

The study introduces a methodology using a skin model and temperature sensors to evaluate a thermoelectric cooling system with an evaporative heat sink.

## Key findings

- The cold side of the thermoelectric module was 3–4.5 °C cooler with the evaporative heat sink after 30 minutes.
- The temperature reduction is insufficient for long-term use or unfavorable conditions.
- Improved heat dissipation from the hot side is crucial for effective wearable cooling systems.

## Abstract

Exposure to hot microclimate constitutes a serious threat to human health, especially in environments where collective protection measures cannot be implemented. Despite technological advances, personal cooling solutions remain insufficient for long-term use. Thermoelectric modules (TEMs) offer a promising pathway for developing cooling garments. This paper deals with temperature variations in a cooling set composed of a TEM and an evaporative heat sink, for different supply currents. A special methodology was adopted that included the use of a skin model placed in a climatic chamber, and temperature sensors that allowed temperatures at several points to be recorded. After 30 min of operation, the cold side temperature of the TEM was approximately 3 °C to 4.5 °C lower than when the heat sink was absent and the TEM was not supplied. This is close to what thermal comfort requires and may become too small for longer operation or less favourable climatic conditions. Enhanced heat dissipation from the hot side is therefore essential for enabling TEMs to function effectively in wearable colling systems, which makes research on heat sinks other than evaporative ones necessary.