The combination refrigerator and freezer have been a staple of all lab applications. There has been a developing emphasis on temperature control in these units because of the value of samples put in these units. Temperature control is not a concern for the PHCbi combination models. These units have separate refrigeration systems; one for the refrigerator and another for the freezer. This design ensures that valuable vaccines, pharmaceuticals, reagents and other biological materials are in an environment that provides uniform and precise temperature control.