Underslung Belt-Driven Truck Refrigeration Unit | DEFU

1. Engine-Driven, No Auxiliary Power Unit

The compressor is belt-driven from the vehicle engine through a multi-ribbed serpentine pulley. There is no second engine to service, no separate fuel system, and no shore-power connection — one powertrain powers both the truck and the cold chain.

2. Underslung Condenser Saves Cargo Space

The condenser is a sealed 960 × 390 × 420 mm chassis-mounted unit, installed under the frame rails between the axles. Nothing intrudes into the cargo box and nothing sits above the roof line.

3. Four-Module Kit, One Supplier

Compressor, condenser, evaporator and in-cab controller are matched, pre-tested and shipped as a single system — with the refrigerant charge, hose routing and wiring diagram defined for the installation.

4. All-Copper Evaporator Core

100% pure copper tubes with internal threading, a hydrophilic blue-fin heat exchanger and a stainless steel housing. Three horizontal discharge outlets distribute air evenly along the length of the body instead of dumping it in one spot.

5. Stable Cooling in High Ambient Conditions

Rated at 30 °C ambient with 2.65 kW (model 280) and 3.5 kW (model 380) at 0 °C evaporating, holding 1.59 kW / 1.96 kW down to −18 °C. The belt drive keeps compressor speed tied to engine speed, so capacity is maintained on long climbs and in dense traffic.

6. In-Cab Digital Control, Dual Screen

The dash-mounted controller shows set point and actual box temperature simultaneously, with defrost, set and up/down keys reachable from the driver's seat. 12 V / 24 V DC control platform.

1. Drive — The engine crankshaft drives a multi-ribbed belt, which turns the Guangyu 5S11 compressor mounted in the engine bay.
2. Compression — Refrigerant R404A is compressed and discharged as high-pressure gas through the insulated pressure line.
3. Condensing — The underslung condenser rejects heat through a 50-tube pure copper coil with dual high-flow fans, converting the gas to high-pressure liquid.
4. Metering — A brass thermal expansion valve controls refrigerant flow into the evaporator.
5. Cooling — The three-fan evaporator absorbs heat from the cargo box and returns low-pressure gas to the compressor. Temperature is set and monitored from the in-cab digital controller.

• Evaporator: 100% pure copper tubes, internally threaded for higher heat transfer; hydrophilic blue-fin coil for corrosion resistance and drainage; stainless steel housing, 1250 × 490 × 220 mm.
• Condenser: all-aluminium parallel-flow core with a large heat sink and heavy-duty steel casing, 960 × 390 × 420 mm, protected by a perforated grille.
• Compressor: Guangyu 5S11 cast-aluminium body with a multi-ribbed serpentine pulley; Guangyu 5H14 available as an option on model 380.
• Piping: insulated copper lines with a receiver-drier and brass expansion valve; all joints leak-tested and the system evacuated before charging.

The kit is designed for a bodybuilder or workshop install rather than a dealership retrofit:

Bolt the condenser bracket to the chassis rails between the axles, keeping the grille clear of the exhaust and the rear axle travel.

Mount the compressor on the engine accessory drive; align the pulley with the crankshaft and set belt tension to specification.

Hang the evaporator from the front bulkhead, leaving clearance for the door and the cargo load line.

Route insulated lines along the frame, fit the receiver-drier and expansion valve, evacuate and charge with R404A.

Connect the controller harness in the cab, set the target temperature and verify pull-down.

Installation and commissioning manual, wiring diagram and hose routing drawing are supplied with every unit.

Light truck cold chain distribution

4.2 m box bodies moving chilled and frozen goods between distribution centres and retail outlets — the reference installation for this system.

Meat, dairy and frozen food delivery

Hold −18 °C across multi-drop routes where doors open frequently; the three-outlet evaporator re-cools the box quickly after each stop.

Pharmaceutical and temperature-sensitive logistics

Stable set-point control with in-cab readout and defrost cycles for 2–8 °C and frozen categories.

Fishery and agricultural transport

Continuous cooling from the point of catch or harvest, independent of mains power at either end of the route.

Engineering and service vehicles

Cooling for mobile workshops and specialised equipment cabins where a conventional reefer unit will not fit.

Fleet retrofit programmes

Standardised kits for distributors and bodybuilders converting existing light trucks to refrigerated configuration.