How to Install a Ceiling‑Mounted Air Cooler in a Cold Storage – Basic Steps

If you are setting up a cold room, one of the key components is the ceiling‑mounted air cooler (also called an evaporator or cold storage fan unit). Getting the installation right is critical for even temperature distribution, efficient defrosting, and long‑term reliability.

Below I’ll walk you through the basic installation process – from unpacking to final checks. For more product details, visit our cold storage air cooler range.

Before You Start – Check the Unit

1. Inspect for loose parts after removing the outer packaging. Tighten any bolts or screws that have come loose during transport.
2. Check the fan blades – make sure they are firmly attached to the motor shaft and that they don’t rub against the protective guard.
3. If the unit is damaged or bent due to shipping, do not hang it. Repair it first or request a replacement.
4. Pressure test – the evaporator is factory‑pressurised with nitrogen and sealed with a capillary tube. Before installation, cut the capillary tube. If you hear a whoosh of gas, the coil is sealed and safe to use. If there’s no sound, there may be a leak – find and fix it before proceeding.

Mounting the Unit

1. Use bolts to hang the unit from the ceiling of the cold room. The bolt hole distances are given in the unit’s manual.
2. Keep a gap of 250–300 mm between the air cooler and the nearest wall (when fan diameter is 400mm or less). This allows proper air circulation and leaves room for maintenance.
3. Make sure the unit is perfectly level after hanging. An uneven cooler can cause poor drainage and fan noise.

Drainage and Piping

1. The drain pipe (for defrost water) must slope downward toward the outside of the cold room. Outside, bend the pipe into a U‑trap to keep a small amount of water inside. This seal prevents warm outside air from being sucked into the cold room.
2. Insulate the drain pipe inside the cold room. If the room temperature is below -20°C, install a heating cable inside the drain pipe to stop ice from blocking it.

Expansion Valve and Sensor

1. When installing the thermal expansion valve (TXV), strap the sensing bulb tightly to the horizontal suction line at the top of the pipe. Make sure it has good contact. Wrap the bulb and the suction line with insulation so the bulb is not affected by the cold room temperature.

Air Flow and Electrical

1. Position the air cooler so that its air outlet is not blocked by a beam or column. Obstacles reduce the throw distance and cause uneven cooling.
2. For D‑series (fluorocarbon) units, the electrical junction box is on the left front side. There are two sizes:
   • Small units (below 22m²) have terminals for defrost heaters with single‑phase or neutral connection.
   • Larger units (above 30m²) use a Y (star) connection for the three‑phase defrost heaters. Because three‑phase heaters are not perfectly balanced, you must connect the neutral wire. This also protects the other two phases if one heater burns out.
3. When the defrost heaters are turned on, the fan power must be cut off. Otherwise, the fan would blow hot air into the room during defrost.
4. The defrost controller should be set to run 1–4 cycles per day. The duration depends on how thick the frost builds up – usually shorter for low‑humidity rooms, longer for high‑humidity or frequent door‑opening cases.
5. The defrost timer should have a delay function – after defrost ends, the fans should not start immediately. Let the residual heat from the heater dissipate first, otherwise warm air enters the room and raises the temperature unnecessarily.
6. Finally, inspect the fins regularly (once a month or as needed). Dust and debris block air flow and reduce cooling efficiency. Clean them with compressed air or a soft brush.

Final Thoughts

Installing a ceiling‑mounted air cooler looks straightforward, but small mistakes – like a missing U‑trap, an uninsulated suction line, or incorrect defrost settings – can cause big problems later. Take your time with each step, follow the manual, and always test the defrost cycle before loading the cold room.

Note: Always work with a qualified refrigeration technician when handling refrigerant and electrical connections. Safety first.