Peltier Cooler Calculator

This tool calculates key performance metrics for thermoelectric (TEC) modules, including cooling power (Q_c), heat pumped to the hot side (Q_h), electrical input power (P_in), coefficient of performance (COP), and required heatsink thermal resistance. It uses fundamental thermoelectric equations based on user-provided electrical and thermal parameters.

COP = Q_c / P_in, representing cooling efficiency—the ratio of useful cooling power delivered to electrical power consumed. A higher COP indicates better energy efficiency; typical TEC COP values range from 0.3–0.7 under practical conditions. This metric helps compare module suitability for battery-powered or energy-sensitive applications.

The Seebeck coefficient quantifies a TEC’s voltage generation per temperature difference (µV/K); here expressed in mV/K for convenience. For standard bismuth-telluride modules, S_m typically ranges from 35–45 mV/K at room temperature. Accurate S_m improves Q_c and COP estimates—consult your module datasheet for the exact value at your operating ΔT.

T_hot (heatsink temperature) and T_cold (cold-side target temperature) define the thermal gradient across the module, which directly affects Q_c, P_in, and COP. Real-world performance degrades significantly as ΔT increases—this calculator models that nonlinearity using standard thermoelectric equations with linearized material properties.

Typical single-stage TECs operate from 1–15 A and 1–16 V (e.g., common 40×40 mm modules: 6 A @ 15.4 V max). Exceeding rated current causes excessive Joule heating and rapid efficiency loss—or irreversible damage. Always verify inputs against your module’s datasheet maximums (I_max, V_max, and Q_c,max).

This value (in °C/W) is the *maximum allowable* thermal resistance from the hot-side module surface to ambient air—accounting for both conduction through the heatsink and convection to ambient. To ensure stable operation, select a heatsink with ≤80% of this value (i.e., derate by 20%) and include interface thermal resistance (e.g., 0.1–0.5 °C/W for TIM).

No—this tool models only single-stage thermoelectric coolers using standard linearized equations. Multi-stage modules have strongly nonlinear behavior, interstage temperature dependencies, and reduced efficiency. For cascaded designs, use manufacturer-specific curves or specialized simulation tools like COMSOL or dedicated TEC modeling software.

Peltier cooling power (Q_c) peaks near zero ΔT and declines as T_hot − T_cold grows due to increased conductive heat leakage and Joule heating dominance. The calculator reflects this intrinsic limitation: at large ΔT, more input power becomes waste heat rather than useful cooling—making high-ΔT applications inherently inefficient.

Results are theoretically sound but assume idealized, steady-state conditions: uniform temperatures, perfect thermal contact, and constant material properties. Real-world performance is typically 15–30% lower due to parasitic losses, mounting pressure effects, and airflow inconsistencies. Always validate critical designs with empirical thermal testing.

Q_c is the heat absorbed at the cold side (cooling capacity); Q_h is the total heat rejected at the hot side. By conservation of energy: Q_h = Q_c + P_in. Since P_in = I × V, Q_h is always greater than Q_c—highlighting why hot-side thermal management is critical for stable operation.