A reliable cold room installation follows a fixed order: prepare the site and floor, assemble and seal the panels, fit doors and accessories, position the refrigeration equipment, run and insulate the piping, wire the controls, pressure-test with nitrogen, evacuate, charge, and commission with a logged pull-down. Skipping or rushing any of these steps—especially leak testing and evacuation—causes most early failures. Use the checklist below with the installation drawings supplied with your equipment.
What should be done before the equipment arrives?
- Confirm the final room layout, door positions and equipment locations against the drawings.
- Check that the site has the correct power supply: voltage, phase and frequency, with a dedicated, correctly rated circuit breaker for the condensing unit.
- Plan the condenser location with good airflow and no hot air recirculation, protected from heavy rain and direct exhaust from other equipment.
- Arrange a drain point for evaporator defrost water outside the room.
- Plan access for unloading panels and lifting condensing units.
- Prepare tools: hex keys for camlocks, sealant guns, pipe cutters, flaring and brazing equipment, nitrogen with regulator, vacuum pump, micron gauge, manifold gauges and charging scale.
How should the floor be prepared?
- Level the base. Panel walls need a flat, level floor; deviations cause gaps at joints and doors that do not seal. Aim for a tolerance of a few millimeters across the room.
- Chillers on an indoor slab can use insulated floor panels or an insulated screed.
- Freezers at −5 °C and below on ground need floor insulation, a vapor barrier below the insulation, and frost-heave protection such as heating cables or ventilation pipes beneath it.
- Forklift traffic needs a structural concrete wearing slab over the insulation, designed for the wheel loads.
- Fit perimeter channels or U-profiles where the wall panels will stand.
How should cold room panels be assembled?
- Start from a corner and assemble walls in sequence according to the panel numbering on the drawings.
- Apply sealant to panel joints before locking, then tighten every camlock fully. A loose camlock leaves an air path that frosts on the cold side.
- Check walls for plumb and square as you go, before fitting the ceiling.
- For wide spans, install ceiling hangers or a support structure as specified. Do not rely on wall panels alone beyond the span shown in the drawings.
- Seal all joints on the warm side with a continuous bead of silicone or PU sealant, which acts as the vapor barrier.
- Fit corner profiles, hygienic coving and trim as specified.
- Seal every penetration—pipes, cables and drain lines—with expanding foam and sealant on both sides.
What accessories must be fitted before start-up?
- Door: adjust hinges or sliding track so the gasket seals evenly; test the inside release handle.
- Door frame heater on freezer doors, wired and tested.
- Pressure relief valve in freezers, with its heater connected, to stop pressure differences stressing panels or locking the door.
- Strip curtain or air curtain to limit infiltration.
- Lighting rated for low temperature and humidity.
- Alarm button or emergency call inside the room, where required by local rules.
How should the refrigeration equipment and piping be installed?
Evaporator
- Mount the evaporator so air throws along the longest dimension, not directly above the door.
- Leave the manufacturer's recommended space behind the coil for return air.
- Level the unit with a slight fall toward the drain outlet.
Condensing unit
- Mount on a level base or wall bracket with anti-vibration pads.
- Keep clearances around the condenser, typically at least 0.5–1 m on the air inlet side and free discharge on the outlet side.
Piping
- Use refrigeration-grade copper sized according to the drawings or the equipment manual for the line length and capacity.
- Braze with dry nitrogen flowing through the pipe to prevent oxide scale inside.
- Slope horizontal suction lines slightly toward the compressor, about 1 cm per meter, so oil returns.
- Fit an oil trap at the bottom of each suction riser and about every 3–6 m of vertical rise, according to the manual.
- Insulate the suction line fully with closed-cell insulation; for freezers, use thicker insulation to prevent condensation and dripping.
- Support pipes with clamps at regular intervals and protect them where they pass through walls.
Drain line
- Slope at least 1:50 toward the outlet, with a trap outside the room.
- In freezers, install drain heater cable along the drain line inside the cold zone.
How should the electrical work be done?
- Wire according to the wiring diagram supplied with the controller and condensing unit.
- Check supply voltage within the equipment tolerance, commonly ±10% of the rated value.
- For three-phase units, confirm phase sequence before start-up, especially for scroll compressors, which can be damaged by reverse rotation.
- Connect protective earth to every metal component.
- Place temperature sensors as specified: room sensor in the return air, defrost termination sensor in the coil.
- Program controller set points: room temperature, differential, defrost interval and termination, drip time and fan delay.
How do you leak-test, evacuate and charge the system?
- Pressure test with dry nitrogen to the test pressure stated in the equipment documentation or local code. Never exceed the rated pressure of any component. Hold for at least several hours, ideally 24 hours, and check for pressure drop after correcting for temperature changes. Check joints with leak-detection fluid.
- Evacuate using a two-stage vacuum pump and a micron gauge to about 500 microns (about 67 Pa) or lower.
- Vacuum hold test: isolate the pump and watch the gauge. A rise that stabilizes indicates residual moisture; a steady rise indicates a leak.
- Charge by weight according to the manual, adjusting for pipe length. Zeotropic blends such as R404A, R407C and R448A must be charged as liquid.
What should be checked during commissioning?
| Check | Typical target |
|---|---|
| Evaporator superheat | About 5–8 K; adjust the expansion valve if outside this range |
| Liquid subcooling at condenser outlet | About 3–6 K, or as specified |
| Sight glass | Clear liquid with dry moisture indicator |
| Suction and discharge pressures | Consistent with design evaporating and condensing temperatures |
| Compressor current | Within nameplate rating |
| Defrost cycle | Heaters energize, termination occurs at set temperature, fan delay works, water drains |
| Safety devices | High- and low-pressure switches trip and reset correctly |
| Pull-down | Room reaches set point within the design time, logged at regular intervals |
What are the most common installation mistakes?
- Uneven floor, leaving gaps at panel joints and doors that never seal.
- Unsealed penetrations around pipes and cables, which let warm, moist air into the panel joints and cause ice.
- Brazing without nitrogen, leaving oxide flakes that block filter driers and expansion valves.
- Skipping the vacuum hold test, so moisture remains and forms acid or ice at the expansion valve.
- Vapor-charging a zeotropic blend, which shifts the refrigerant composition and reduces capacity.
- Missing oil traps on suction risers, starving the compressor of oil.
- Condenser in a confined space, causing hot air recirculation and high-pressure trips on hot days.
- Unheated freezer drain lines, which freeze and flood the room with defrost water.
- Loading product before pull-down is complete, which overloads the system on its first day.
Most of these problems are invisible on the day of start-up and only appear weeks later. A careful commissioning record makes them easier to diagnose.
What should be handed over to the owner?
- As-built drawings, wiring diagrams and controller settings.
- Commissioning record with pressures, temperatures, superheat, current and refrigerant charge.
- Operating instructions: loading limits, door discipline, alarm response and daily checks.
- A maintenance schedule: condenser cleaning, drain checks, door gasket inspection and periodic leak checks.
What should the owner check after handover?
- Daily: room temperature display and alarms, door closing and gasket condition, no ice on the evaporator face or floor.
- Weekly: drain outlet clear, condenser area free of debris, no unusual noise from compressor or fans.
- Monthly or quarterly: condenser coil cleaning, more often in dusty or coastal sites; check defrost operation and heater current.
- Annually: leak check, electrical connection tightness, pressure switch test and a full performance check against the commissioning record.
Our cold rooms are supplied with installation drawings and video guidance, and our condensing units ship with wiring diagrams. For project-specific installation support, contact our team.
Frequently asked questions
How long does it take to install a cold room?
A small walk-in cold room can often be assembled and commissioned in one to three days by an experienced crew. Larger multi-chamber rooms take longer, depending on floor work, piping length and site conditions.
What vacuum level is needed before charging refrigerant?
A common target is 500 microns (about 67 Pa) or lower, measured with a micron gauge, followed by a hold test to confirm the system is dry and leak-free.
Why does a freezer room need a pressure relief valve?
When warm air enters and cools, the room pressure drops below outside pressure. The valve equalizes it, preventing panel stress and making the door easier to open.
Do cold room panels need sealing after camlocking?
Yes. Sealant on joints and a continuous bead on the warm side form the vapor barrier and stop air leaks, which otherwise cause frost, condensation and higher energy use.
