Qc=2N[αI (Tc+273)-LI²/2σs-ks/L × (Th-Tc)]
U=2N[IL/σS+a(Th-Tc)]
△ T=[ I α ( Th+273 ) – L I ²/ 2 σ S ] / ( k S / L + I α )
ε=Qc/UI
Qh=Qc+IU

Explanation to symbois:

Qc: Cooling power of TECM(W)
U: Operation voltage of TECM(%)
I: Operation current of TECM(A)
△ T :Temperature difference when current is I and cooling power is zero( ℃ )
ε : TECM's cooling efficiency(%)
Qh: Heating power of TECM(W)
△ Tmax:
Maximum temperature difference rcachcd when the cooling power of TECM is zero and the temperulure of hot side is a specitied value( ℃ )
I max:
Current when TECM reaches the maximum temperature difference (A)
I ε max :
Current attached when the hot-side and cold-side temperature of TECM is a specified value and it requires getting the maximum efficiency(A)
N: Number of thermoclectric element of TECM
a: Seebeck coefficient of thermoclectric material(V/ ℃ )
σ : Electriacl conductivity of thermoelectric material(I/CM. Ω )
k : Thermo-conductvity of thermoelectric material (N/CM. ℃ )
Th : Temperature of hot-side when TECM operating ( ℃ )
Tc : Temperature of cold-side when TECM operating ( ℃ )
L: Length of thermoelectric element (cm)
S : Areu of thermoelectric element(cm²)

The value's range of α `σ and k taken by orient electric company