What Are the Installation Requirements and Precautions for Cold Rooms?

What are the installation requirements and precautions for cold rooms?

To help ensure proper cold room installation, we provide six common installation requirements, including panel installation, unit coolers, refrigeration equipment, refrigerant piping, power distribution, and refrigerant charging.

1. Installation Requirements for Assembling Cold Room Panels

Review the project design and building material list, and carefully inspect materials and accessories.

Before installation, check the quantity of cold room panels. When loading and unloading storage panels, handle them with care and lay a scratch-resistant layer at each panel and floor joint.

When assembling the cold room, there should be a gap between the wall and the roof, the floor or ground must be level, and the construction environment should be kept clean.

Before fixing the interior of the storage unit with aluminum angle, seal it with glass sealant first, then secure it with aluminum angle using solid tension. The distance between rivets is 300 mm. The distance between the upper and lower sides of the door is 100 mm.

Cold Room Installation

2. Technical Requirements for Unit Cooler Installation

When selecting the hanging point location, first consider the position for air circulation. Second, consider the orientation of the cold room structure.

The gap between the evaporator and the panel should be greater than the thickness of the evaporator.

All suspension bolts of the unit cooler should be tightened. Seal the bolt and suspension bolt perforations with sealant to prevent cold bridging and air leakage.

When the ceiling-mounted evaporator is too heavy, use No. 4 or No. 5 angle iron to make a crossbeam. The beam should span across to another top panel and wall panel to reduce load bearing.

Unit Cooler

3. Installation Requirements for Refrigeration Equipment

Semi-hermetic or hermetic compressors should be equipped with an oil separator, an appropriate amount of oil should be installed in the oil area, and when the evaporation temperature is below -15°C, install a gas-liquid separator and add an appropriate amount of refrigerant oil.

A vibration-damping rubber base should be installed under the compressor base.

When installing the unit, leave maintenance space for easy observation of gauges and adjustment of valves.

The high-pressure gauge should be installed at the tee of the liquid storage charging valve.

The overall layout should be reasonable and the color unified. The installation structure of each model unit should be consistent.

Bitzer Refrigeration Unit

4. Installation Requirements for Refrigerant Piping

The copper pipe diameter should be strictly selected based on the compressor's suction and discharge valve connections. When the distance between the condenser and compressor exceeds 3 meters, the pipe diameter should be increased;

The condenser suction surface should maintain a distance of more than 400 mm from the wall, and the outlet should maintain a distance of more than 3 meters from obstacles;

The inlet and outlet pipe diameters of the liquid receiver should follow the discharge and liquid outlet pipe diameters indicated on the unit sample.

Refrigerant Piping

The compressor suction line and evaporator return line should not be smaller than the dimensions indicated on the sample to reduce the internal resistance of the evaporator piping.

When making the regulating station, each liquid discharge pipe should be cut at a 45-degree angle and inserted into the bottom, and the liquid inlet pipe should be inserted into the regulating station at one-quarter of the pipe diameter;

The discharge pipe and return air pipe should have a slope. When the condenser is positioned higher than the compressor, the discharge pipe should slope toward the condenser, and a liquid trap should be installed at the compressor discharge outlet to prevent gas from cooling and liquefying and flowing back to the high-pressure discharge port after shutdown, causing liquid compression on restart;

The evaporator outlet of the suction line should be installed with a U-bend. The suction line should slope toward the compressor to ensure smooth oil return;

The expansion valve should be installed as close to the evaporator as possible. The solenoid valve should be installed horizontally with the valve body vertical, and pay attention to the liquid direction;

If necessary, install a filter on the compressor return line to prevent dirt from entering the compressor system and to remove moisture from the system;

Before fixing the refrigeration system, use nuts and lock nuts, wipe with refrigeration oil for lubrication and to enhance sealing. After fastening, wipe clean. The root of each zone door should be tightly locked;

The expansion valve thermal bulb should be fixed with a metal clamp at 100mm-200mm from the evaporator outlet and tightly wrapped with a double-layer insulation layer;

After installing the refrigeration system, ensure overall aesthetics and color consistency. There should be no unevenness between pipes.

5. Installation Requirements for Power Distribution System

Each contact point should be equipped with a maintenance wire number;

Strictly follow the drawing requirements to make the electrical control box and connect to the power supply for no-load testing;

Mark the name on each contactor;

Secure each electrical component wire with binding wire;

Electrical contacts should be tightly attached to the wire connectors, and the main wire connectors should be tightly clamped with wire clamps, and tinned if necessary;

Electrical Box

Lay out and secure the conduits for each equipment connection with clamps. When connecting PVC pipes, glue them together and seal the pipe ends with tape;

The distribution box should be installed horizontally and vertically, with good ambient lighting and a dry room for observation and operation;

The area occupied by wires in the conduit should not exceed 50%;

Wire selection must have a safety factor, and the surface temperature of the wire should not exceed 40°C during equipment operation or defrosting;

The circuit system must be a five-wire system; if there is no ground wire, install a ground wire;

Wires should not be exposed to the air to avoid long-term exposure to sunlight and wind, wire aging, short circuits, leakage, etc.;

The installation of conduits should be aesthetically pleasing and sturdy.

6. Technical Requirements for Refrigeration System Commissioning

Measure the power supply voltage;

Measure the resistance of the compressor's three sets of windings and the motor insulation;

Check the open/close status of each valve in the refrigeration system;

After evacuation, inject refrigerant into the liquid receiver to 70%-80% of the standard charge, then run the compressor to add gas from the low-pressure side until sufficient;

After startup, first listen to the compressor sound to see if it is normal, and check whether the condenser and air cooler are operating normally. Check whether the three-phase current of the compressor is stable;

After cooling stabilizes, check each part of the refrigeration system, such as discharge pressure, suction pressure, discharge temperature, suction temperature, motor temperature, crankcase temperature, and the temperature before the expansion valve. Observe the frosting condition of the evaporator and expansion valve, and observe the oil level and color change in the oil sight glass. Check whether the equipment operating sound is abnormal;

Set parameters and expansion valve opening based on the cold room's frosting and usage conditions.