5,000 m³ Chili Cold‑Storage Project in Zunyi, Guizhou | High‑Humidity Mountain‑Region Vegetable Preservation EPC Case

Client: Zhuohao Agricultural Technology Co., Ltd. (Guizhou, China)

Service Delivered: Multi‑chamber cold‑storage layout design, insulation panel installation, refrigeration system deployment, site commissioning, URS‑aligned acceptance & operator training

Located in Zunyi, Guizhou mountainous area, this 5000 m³ vegetable cold‑storage facility is purpose‑built for local chili harvest season bulk storage. Zunyi features subtropical mountain climate with long high‑humidity rainy seasons. Without well‑optimized cold‑room envelope and energy‑saving refrigeration configuration, fresh chili easily suffers chilling injury, surface shriveling and mould decay during preservation.

The facility consists of three independent sealed cold chambers, designed for flexible operating temperature range of ‑5 °C ~ +8 °C, to satisfy different preservation requirements for fresh chili and other local seasonal vegetables, complying with strict energy‑efficiency and URS (User Requirement Specification) acceptance standards.

Core Project Metrics

• Total cold‑storage volume: 5,000 m³, divided into 3 independent cold rooms
• Adjustable operating temperature range: ‑5 °C ~ +8 °C for chili & local vegetable storage
• Compliance: Energy‑saving design standard, URS user‑specification hand‑over documents
• Project delivery scope: Envelope construction, full refrigeration hardware installation, on‑site test run and acceptance

Pre‑Construction Operational Pain Points

Before building this dedicated chili cold‑storage, the local agricultural operator faced prominent post‑harvest bottlenecks caused by mountain‑region climate:

1. High spoilage risk in humid mountain environment
   Local rainy‑season ambient humidity stays high. Temporary simple storage solutions could not stabilize temperature & humidity; fresh chili was prone to shriveling, mold and quality loss after harvest.
2. Lack of separated chambers for different‑batch chili inventory
   Large single cold room cannot separate newly‑harvested batches and stock in mid‑term preservation. New‑crop field‑heat input disturbed storage environment for existing goods.
3. High historical cold‑room energy consumption
   Previous makeshift cold‑rooms adopted electric defrost solutions, creating heavy power consumption and frequent temperature fluctuation during defrost cycles, damaging sensitive chili produce.
4. Safety risks for cold‑room access & equipment operation
   Old‑style cold‑room doors lacked anti‑lock safety mechanism and condensation‑proof measures, bringing potential safety hazard for on‑site workers.

Local‑site constraint note: Guizhou mountain‑zone projects need to balance insulation performance, defrost mode and anti‑condensation design under persistent high‑humidity ambient conditions.

Custom‑Built Engineering Solutions

1. Intelligent Energy‑Saving Refrigeration System

• Compressor hardware: 3 × Emerson Copeland™ ZPS25KQE scroll compressors (25 HP each)
• Refrigerant: Eco‑friendly R448A refrigerant (GWP=1273)
• Control components: Danfoss™ electronic expansion valves
• Energy‑saving optimizations:
  1. Variable frequency drives (VFD) reduce frequent compressor start‑stop cycling losses according to real‑time thermal‑load
  2. Hot‑gas bypass defrost technology; cuts energy consumption by about 40 % compared with traditional electric heating defrost, and avoids sharp temperature disturbance to stored chili vegetables.

2. Insulation Envelope & Special‑Function Cold‑Room Doors

Component	Specification	Site‑specific Optimization
Cold‑storage wall & roof panels	100 mm double‑sided color‑steel polyurethane panels, Class B1 flame‑retardant	Reliable thermal performance for Guizhou high‑humidity mountain conditions; good anti‑moisture penetration
Electric sliding cold‑room doors	Polyurethane filled, aluminum‑alloy frame, 0.5 mm double‑sided color‑steel surface	Anti‑lock safety release device; built‑in electric heating strip for anti‑condensation; emergency alarm system
Loading vestibule air curtain	Yongxing Diamond high‑speed air curtain (2300 mm), powder‑coated housing, pure‑copper 220 V motor	Blocks inflow of hot‑humid outside air during frequent door opening operations

On‑site Assembly & Cold‑Room Installation Photographs

Original project photos record insulation panel lifting, refrigeration unit mounting, cold‑room door installation and XPS floor extruded‑board laying for this Zunyi chili cold‑storage.

Measurable 12‑Month Operational Outcomes After Commissioning

✅ Three‑independent‑chamber layout supports batch‑separated chili storage, prevents fresh harvest field‑heat from disturbing existing preserved stock
✅ Hot‑gas bypass defrost plus VFD variable‑frequency setup greatly lowers overall facility power‑consumption; reduces temperature fluctuation during defrost cycles
✅ Anti‑condensation door system plus high‑speed air‑curtain mitigate interior condensation risks brought by Guizhou mountain‑area humid air
✅ Safety‑optimized cold‑room door assemblies eliminate worker trapping risks during daily warehouse operations
✅ Stable adjustable‑range cold chambers can serve both fresh chili and other seasonal local vegetable preservation needs.

Practical Lessons Learned For Vegetable Cold‑Storage In Humid Mountainous Regions

Summarized from real‑world Zunyi chili cold‑storage construction, key pitfalls for agricultural cold‑storage investors in high‑humidity mountain zones:
1. Adopt electric heating defrost for vegetable cold rooms → large energy waste and big temperature swings which easily damage sensitive fresh produce such as chili peppers
2. Build one single large cold room for multi‑batch vegetable incoming → newly‑harvest field‑heat destabilizes storage environment for goods already in‑stock
3. Omit anti‑lock safety release device for cold‑room sliding doors → personnel trapping safety hazard
4. Skip high‑speed air‑curtain at loading doorway → large‑volume hot‑humid outdoor air inflow, interior condensation and higher spoilage rate
5. Ignore anti‑condensation heating strip on cold‑room doors → door‑frame dew dripping accelerates panel aging.

FAQ For Mountain‑Area Vegetable Growers & Agricultural Operators

Q1: What temperature range is recommended for fresh chili pepper cold‑storage?
A: Fresh chili peppers are chilling‑sensitive vegetables. General recommended storage sits around 7‑10 °C with RH 90‑95 %; long‑time storage below 6 °C will trigger chilling injury including surface pitting, softening and mold outbreak. This project’s ‑5 °C ~ +8 °C adjustable range supports both fresh chili and other vegetable varieties.

Q2: Why hot‑gas bypass defrost is preferred over electric defrost for chili cold‑rooms?
A: Hot‑gas bypass defrost consumes ~40 % less power, and avoids dramatic indoor temperature spikes which may cause quality loss for temperature‑sensitive chili produce.

Q3: Why use independent multi‑chamber design for chili cold‑storage?
A: Separate chambers isolate different harvest batches. Newly‑picked chili carrying heavy field‑heat can be processed in one room without disturbing already‑preserved stock in other compartments.

Request Your Custom Vegetable Cold‑Storage Proposal

If you plan agricultural cold‑storage construction for vegetables in high‑humidity mountain‑zone regions, share your total target volume, main crop varieties and local ambient‑humidity characteristics. Our engineering team can deliver energy‑saving oriented layout concept plus itemised USD‑denominated quotation.