SunDanzer (WHO Approved) Solar Battery-Free Vaccine Refrigerator – If your customer requires a World Health Organization (WHO) approved vaccine refrigeration system, then you will want to use the SunDanzer BFRV 15liter or 55liter model. Remember that the entire system should be installed per WHO specifications in order to meet the standard – the refrigerator is just one component and will not work well in a poorly designed or poorly installed system. Because these are DC direct units, the manufacturer recommends a certain module orientation. The modules need to be arranged in an East / West array. Refer to the information below.