The Sub Zero BI-48SD/O Refrigerator 48" Built-in meets with your preservation needs efficiently. Microprocessor continuously supervises the temperature conditions in the system and alters the temperature in the refrigerator for achieving better performance. The Sub Zero BI-48SD/O Refrigerator 48" Built-in has separate compressors and cooling systems so that the food items are preserved at optimal temperatures. Crisper drawers are placed near the evaporator so that high humidity levels are maintained in the system thereby ensuring the freshness of the food for a longer period. The air purification system in the Sub Zero BI-48SD/O Refrigerator 48" Built-in removes mold viruses and bacteria thereby safeguarding the food stored from quick spoilage.