Peltier / TEC Calculator

A Peltier module (or TEC — thermoelectric cooler) is a solid-state device that pumps heat from one side to the other using electricity, commonly used to cool electronics, sensors, or small enclosures. Enter your hot side temperature, cold side temperature, heat load, ambient temperature, and thermal resistances, then select a module size and optimization mode to calculate the required operating current. Secondary outputs include operating voltage, power consumption, temperature difference (ΔT), ΔT/ΔTmax ratio, and coefficient of performance.

°C

Temperature on the hot side of the Peltier module

°C

Desired temperature on the cold side

W

Heat load that needs to be removed

°C

Environmental temperature around the system

K/W

Thermal resistance from TEC hot side to ambient

K/W

Thermal resistance from load to TEC cold side

Optimize for power consumption or physical size

Results

Operating Current

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Operating Voltage

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Power Consumption

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Temperature Difference (ΔT)

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ΔT/ΔTmax Ratio

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Coefficient of Performance

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Frequently Asked Questions

What is the difference between hot side and cold side temperature?

The hot side temperature is where heat is rejected (typically to ambient), while the cold side temperature is where cooling occurs. The temperature difference (ΔT) between these sides determines the Peltier module's performance requirements.

How do I determine the thermal resistance values?

Thermal resistance depends on your heat sink design and thermal interface materials. Typical values range from 0.5-2 K/W for good heat sinks with fans, and 2-10 K/W for passive cooling. Check your heat sink specifications or measure experimentally.

What is the ΔT/ΔTmax ratio and why is it important?

This ratio indicates how close you're operating to the module's maximum temperature difference capability. Values above 0.7 indicate you're pushing the module hard, which reduces efficiency and may require a larger module.

Should I optimize for minimum power or minimum size?

Choose minimum power for battery-operated applications or when electrical efficiency is critical. Choose minimum size when space is limited and power consumption is less important. Balanced mode provides a good compromise.

Why is my coefficient of performance (COP) low?

COP decreases with larger temperature differences and higher heat loads. Peltier modules are most efficient at small ΔT values. Consider improving thermal resistance or using multiple stages for better performance.

Can I use this calculator for heating applications?

Yes, Peltier modules can provide both cooling and heating. For heating mode, reverse the hot and cold side temperatures. The heat output will be the electrical power plus the heat pumped from the cold side.

What happens if I exceed the calculated operating current?

Exceeding the optimal current increases power consumption with diminishing cooling returns, and may damage the module through overheating. Always operate within the calculated parameters for optimal performance and longevity.

How accurate are these calculations?

These calculations provide good estimates based on typical Peltier module characteristics. Actual performance may vary ±15% due to manufacturing tolerances, thermal interface quality, and real-world conditions. Always verify with prototypes for critical applications.