TR-300T Refrigeration Units for Cargo Van Introduction. Kingclima TR-300T van refrigeration unit is a split design. This vehicle powered roof top mounted refrigeration units can apply for mid-sized sprinter / Kingclima vans, other medium sized refrigerated vans with container volume of 10~15m³. With R404a refrigerant, the temperature range is -20℃ to 30℃ for transporting