An important feature of Peltier modules is the maximum achievable temperature difference dTmax. This is specified in K (Kelvin), often mistakenly in °C (nominally the same, but not right). It is misleading that this maximum temperature difference in the data sheets refers to operating in a vacuum and therefore in practical operation under atmospheric conditions can by far not be reached. This reference value is suitable as a comparison at best. Unfortunately, this situation is usually more or less concealed shamefully in the data sheets, our delivery plant is no exception. On the other hand, if everyone is telling fibs, the basis of comparison is true nevertheless.

Caution: the maximum temperature difference is achieved at 0 W pumped heat output, the maximum heat pump capacity at 0 K temperature difference between hot and cold side!

Rule of thumb: The thicker a Peltier module the higher dTmax, the thinner a Peltier module, the higher the heat pump output.