8. What do the thermoelectric parameters Imax, Vmax, dTmax and Qmax mean?
As current flows through any material, heat is generated.
This principle also applies to thermoelectric material. At a certain point, the heat generated can internally offsets the thermoelectric module’s ability to pump heat.
Each thermoelectric module has a heat-pumping limitation. This limit is referred to as Qmax.
The current associated with Qmax is referred to as Imax. The corresponding voltage across the coolers is referred to as Vmax.
If a TEC is completely insulated and isolated from the environment and running at Imax, it will produce its maximum temperature difference, dTmax. At this point, it will also be pumping no heat whatsoever.
As heat is applied to the cold side of the TEC, the temperature differential is suppressed. Effectively, one trades temperature differential for heat pumping. As such, if the temperature differential is 0, the corresponding heat load is Qmax.
The coefficient of performance (COP) is defined as the amount of heat pumping one gets for each unit of electrical power supplied.