Thermal isolation of sections of individual
thermoelectric elements, modules and arrays of modules can
be used to progressively heat and cool a working fluid so as
to increase system efficiency when compared with that of
standard TE modules with isothermal hot and cold sides.
Equations for performance in heating and cooling modes are
derived for steady state conditions with one-dimensional,
temperature-independent material properties. Analytical
approximations with closed form solutions are given for
COP in cooling and heating. Results are compared with
precise numerical solutions. Efficiency is shown to increase
up to 120% over that of conventional TE modules for
certain important applications that involve cooling or
heating of a fluid or solid, such as air conditioning and
heating. Limitations of the technology are also discussed. It
is shown that in the particular case of steady state
refrigeration usage benefit is limited or does not occur.
Predicted performance of air conditioning systems using
thermal isolation, in combination with advanced TE
materials with ZT of 2 to 3 are shown to be comparable to
refrigerant 134A.