1.  When the ideal operating temperature is less than the ambient temperature (active cooling);
2.  When the design requires a small size cooling device or there are tight space restrictions;
3.  When low maintenance cost and high solid state reliability is desired;
4.  When an application requires localized or spot cooling;
5.  When the design calls for precise temperature control especially when the ambient temperature varies greatly;
6. When low weight or portable cooling/heating is desired.