The D4.5E9 is engineered specifically for deep-freeze storage and blast-chilling applications operating at a room temperature of -35 °C. Powered by dual 400 mm external rotor motors, the unit delivers a high-velocity air volume of 7800 m³/h (2*3900 m³/h) and a strong 10-meter air throw. This high-volume configuration makes it highly effective at maintaining uniform temperature levels in medium-sized commercial walk-in freezers, eliminating warm pockets near racking corners.

Operating at evaporating temperatures as low as -42 °C causes rapid ice buildup on cooling coils. The D4.5E9 mitigates this with an extra-wide 9.0 mm fin pitch (3 FPI) paired with a staggered copper tube arrangement. The wide spacing allows for extensive frost accumulation without choking the airflow, extending the time between defrost cycles. Internally, the inner-grooved copper tubes generate high refrigerant turbulence to break up thermal oil barriers, maximizing overall heat exchange.

To withstand constant humidity cycling and washdowns, the casing is constructed from high-quality prepainted steel panels combined with an aluminum internal tube sheet. The unit features an integrated 4.7 kW high-output electric defrost system with stainless steel heating elements fitted in both the coil core and the insulated drip tray. This dual-zone heating ensures all melted frost is completely drained through the 1" port before it can refreeze. Every unit is pressure tested at 2.8 MPa to guarantee absolute leak-tightness.

Ruifujie is an established global manufacturer specializing in advanced commercial refrigeration hardware and thermal transfer systems. For over 20 years, our production facilities have engineered high-efficiency industrial evaporators, air-cooled condensers, and robust commercial compressors, including scroll, screw, and semi-hermetic reciprocating models. By combining automated production lines, precise mechanical tube-expansion, and strict multi-phase pressure testing, we deliver highly reliable systems that meet the rigorous standards of modern cold chain logistics. Ruifujie remains a trusted OEM/ODM manufacturing partner for engineering contractors and refrigeration distributors across Europe, North America, and the Middle East.

A1: In rooms operating at -35°C, any water that melts off the coil will instantly refreeze upon hitting a freezing cold metal drain pan. To prevent this block, we install independent stainless steel heating elements directly within both the coil block and underneath the drip tray. This ensures the pan is heated simultaneously, allowing all meltwater to flow freely out of the 1" drain port before the cooling cycle restarts.

A2: Yes. The D4.5E9's internal coil design, structural metallurgy, and 2.8 MPa pressure rating are fully compatible with a wide range of standard industrial fluorinated refrigerants, including R404A, R23, R134a, and R22.

A3: A completely flat fin allows a laminar boundary layer of air to form, which acts as an insulator and reduces heat exchange. The double-sine wave pattern with open-window cuts physically forces the passing air into a turbulent state, breaking up this boundary layer and bringing the warm room air into continuous, direct contact with the cold fin surfaces.

A4: All Ruifujie products are securely packed in reinforced wooden boxes to ensure structural protection during transport. For ocean freight, units can be shipped with a pre-charged holding refrigerant or nitrogen pressure; however, for air freight safety compliance, all products must be shipped completely empty of refrigerant.

A5: Our standard trade terms are FOB Shenzhen or EXW, with all transactions settled in USD. We support secure payment methods including Telegraphic Transfer (T/T) and Western Union to facilitate seamless commercial transactions.

Ruifujie offers competitive, tiered pricing for cold room contractors, engineering firms, and commercial refrigeration distributors. If you are designing a low-temperature storage project and need technical layouts or bulk pricing, send over your room dimensions and local voltage standards. Our technical sales team will provide a tailored hardware match and an official commercial quote within 8 hours.