Cooling and Heating Capacity

Cooling and Heating Capacity

The cooling and heating capacity of a given thermoelectric system is dependent upon the operating temperature, how many thermoelectric modules are used, the type of thermoelectric modules used, and how much power is applied. Figures 1 and 2 show the variation of cooling and heating capacities with applied current for Solid State Cooling System’s ThermoCube.

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Figure 1

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Figure 2
There is an optimum current, Iopt, at which the maximum cooling capacity is achieved. Cooling capacity decreases at current levels above Iopt as resistive heating, which increases with the current squared, overwhelms the Peltier cooling which increases linearly with current. The overall heating capacity continues to increase with current due to resistive heating. The upper limit on heating is achieved at Imax, the module’s maximum operating current. The variation of cooling and heating capacities with temperature runs in opposite directions (see Figure 3).

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Figure 3
At a constant applied current, the cooling capacity increases as the cold side temperature increases and the heating capacity decreases as the cold side temperature increases. The maximum temperature between hot and cold sides also changes with current applied. Applications where the object being cooled is much colder the heat sink require higher current levels than applications where the difference in temperatures is less. Solid State Cooling Systems optimizes the trade off between cooling capacity, power consumption and capital cost to maximize the benefits to our customers.