8,500 m³ 10‑Chamber Controlled‑Atmosphere Cold‑Storage Project In Zigong | Basin‑Climate Fresh‑Fruit Preservation EPC Case

Project Date: September 2025

Client: Regional fresh‑fruit producing enterprise in Zigong, Sichuan

Service Delivered: Multi‑chamber CA layout design, air‑tight enclosure construction, refrigeration & gas‑regulation hardware installation, centralized monitoring system, on‑site commissioning and URS‑compliant acceptance

This large‑scale controlled‑atmosphere cold‑storage technology cold‑storage facility is built in Zigong, located in the humid Sichuan basin. The local subtropical climate features frequent overcast weather, high year‑round humidity and hot summer ambient temperatures. Without robust air‑tight CA construction and anti‑condensation measures, stored fresh produce suffers accelerated ripening, mould and quality loss.

The client required ten independent CA chambers for batch‑wise fresh‑fruit preservation. Core objectives included precise stable temperature control, unified centralised platform for gas‑humidity‑temperature management, balanced operating energy‑efficiency and full compliance with user requirement specification (URS) for commercial produce warehousing. Separate chambers enable flexible stock management for different fruit varieties and staggered harvest batches.

Core Project Metrics

• Total CA cold‑storage volume: 8,500 m³, split into 10 fully independent sealed chambers
• Design operating temperature for all CA rooms: 2‑7 °C for multiple types of fresh commercial fruits
• Engineering deliverables: Air‑tightness pressure test, full equipment commissioning, URS‑aligned hand‑over documentation
• Design targets: Independent chamber control, real‑time remote monitoring, optimised long‑term energy consumption

Pre‑Construction Operational Pain Points

Our engineering team analysed the client’s existing fruit‑handling workflow and identified key bottlenecks for this basin‑area CA build:

1. Need for isolated chambers for mixed fruit batches
   Different fruit varieties demand distinct oxygen / carbon‑dioxide set‑points. Shared single chambers force compromise on gas parameters and shorten permissible storage time.
2. High‑humidity basin environment challenges for CA air‑tightness
   Zigong’s persistent damp ambient conditions place extra stress on panel joints and door seals. Minor air leakage quickly undermines CA preservation performance.
3. Demand for unified centralised supervision across ten chambers
   Manual per‑room checking would create heavy labour overhead. Client required one platform to read temperature, humidity and gas data for all ten chambers, plus remote alarm capability.
4. Balance capital expenditure with ongoing power consumption
   Large‑volume CA facilities carry substantial running‑cost risk. Equipment selection needed to balance upfront investment against year‑round energy‑saving performance.

Local‑site constraint note: In Sichuan basin humid locations, CA joint sealing quality directly determines actual shelf‑life outcome; even small leaks erase most benefits of controlled‑atmosphere investment.

Custom‑Built Engineering Solutions

Every chamber was equipped with independent refrigeration and gas‑control hardware, while all units feed back to one central monitoring platform.

1. Refrigeration System Configuration

Each of the ten CA storage chambers is fitted with dedicated 20 HP Italian Refcomp piston condensing unit, complete with condensers, solenoid valves and pressure‑control assemblies. Piston‑type hardware delivers reliable stable cooling performance for cyclic CA‑room loading cycles.

Supporting evaporators adopt Zhejiang Kaili DL‑210 high‑efficiency air coolers, engineered for uniform temperature spread inside each chamber together with dependable defrost sequences to minimise local fruit temperature shock.

2. Insulation & Envelope Construction

• Wall panels: 100 mm double‑sided colour‑steel polyurethane panels with B2 fire‑retardant rating. Good waterproof and moisture‑blocking properties reduce thermal load for the high‑humid basin operating environment.
• Strict multi‑step joint‑sealing procedures are implemented for all panel seams to satisfy CA air‑tight acceptance criteria.

3. Integrated Controlled‑Atmosphere Gas‑Regulation Hardware

Independent Rainox CA gas‑handling assemblies serve each storage compartment:
– Oxygen‑nitrogen generation unit built around Siemens PLC core, paired with Schneider electrical components and SMC pneumatic valves
– CO₂ scrubber system adopting Panasonic control modules plus German‑sourced pneumatic actuators, supporting intelligent automatic regeneration cycles.

4. Centralised Monitoring & Protection Platform

Jingchuang full‑automatic intelligent control system unifies management for all ten CA chambers:
– Comprehensive motor protection functions: phase‑loss, phase‑sequence, overload and under‑voltage safeguards
– Continuous real‑time tracking for temperature and humidity; multi‑level alarm triggering for out‑of‑range conditions
– Automatic historical‑data logging plus mobile‑client remote access for off‑site supervisory checks.

Multi‑Chamber CA Facility On‑Site Assembly & Finished Interior Photographs

Original on‑site documentation capturing CA compartment interior views, workers applying air‑tight joint sealant and refrigeration‑unit installation stages for this Zigong 8500m³ project.

Measurable 12‑Month Operational Outcomes After Commissioning

✅ Ten‑chamber independent layout allows separate gas‑parameter tuning for different fruit batches, maximising usable off‑season storage duration
✅ Careful CA joint‑sealing construction mitigates humid‑basin air‑leak risks and maintains stable controlled‑atmosphere conditions
✅ Single unified monitoring platform cuts routine on‑site inspection workload and provides remote early‑warning capability
✅ Selected hardware balances procurement cost and continuous‑run energy‑efficiency for year‑round commercial fruit operation.

Practical Lessons Learned When Building Multi‑Chamber CA Cold‑Storage In Humid Basin Regions

From hands‑on Zigong project delivery, key pitfalls for investors planning multi‑compartment CA facilities:
1. Combine multiple fruit varieties inside single CA chamber → cannot optimise gas set‑points for each crop, reduces overall preservation performance
2. Reduce attention to panel‑joint sealing work in high‑humidity basin climate → slow air leakage degrades CA effect and shortens fruit shelf‑life
3. Rely on manual separate inspection for many CA rooms → high labour cost and delayed fault‑response time
4. Over‑prioritise low‑initial‑cost hardware without evaluating seasonal power consumption → high recurring electricity bills reduce project profit margin.

FAQ For Fruit Enterprise Managers Planning Multi‑Room CA Investment

Q1: What is the operating temperature range for these Zigong CA chambers?
A: Designed set‑point runs 2‑7 °C, suitable for multiple varieties of commercially‑stored fresh fruits; exact gas and temperature parameters need further tuning per specific crop.

Q2: Why build ten separate CA chambers instead of fewer large rooms?
A: Independent compartments enable different O₂ / CO₂ configurations for mixed fruit varieties, and support staggered incoming harvest batches without disturbing stock already in preservation.

Q3: What is the main technical risk for CA cold‑storage built inside Sichuan humid basin locations?
A: Air‑tightness degradation at panel seams. Persistently damp ambient conditions amplify the negative impact of small leaks on controlled‑atmosphere preservation performance.

Q4: What functions does the centralised monitoring system deliver for multi‑chamber CA projects?
A: It unifies temperature‑humidity‑gas‑status reading for all rooms, automatic fault alarms and mobile remote‑access, lowering daily management burden for operators.

Request Your Multi‑Chamber Controlled‑Atmosphere Cold‑Storage Proposal

If you plan multi‑compartment CA construction for fresh‑fruit business, please share total target volume, fruit‑variety portfolio and local climate background. Our engineering team can deliver air‑tight‑focused layout concept plus itemised USD‑denominated quotation.