Cold storage for oranges oranges require a standard temperature of 3-8°C (37-46°F) and a relative humidity of 85-95%. Prepared correctly and held in those conditions, commercial oranges keep their juiciness and bright colour for 3 to 5 months. Building a cold store of this kind costs from 80,000,000 VND for a small volume to over 140,000,000 VND at industrial scale.
With over 20 years of experience, Tan Long (tanlongvn.com) is a contractor specialising in turnkey design and installation of cold stores for agricultural produce, providing optimal ethylene control and moisture-loss prevention for growers and exporters in Vietnam.
Core technical standards for keeping fresh oranges in cold storage
Controlling the micro-climate accurately inside the cold storage is critical if oranges are not to rot or dry out after harvest.
What are the ideal temperature and humidity for oranges?
The ideal storage temperature for fresh oranges is 3-8°C, together with a relative humidity of 85-95%. Holding the temperature below 8°C inhibits the growth of Penicillium mould, while staying above 3°C avoids chilling injury, which causes dark spots on the peel. Oranges are 80-85% water, so store humidity must stay above 85% to limit moisture loss and keep the peel from wilting and wrinkling, in line with post-harvest produce storage standards.
Respiration and the sensitivity of oranges to ethylene
Oranges are non-climacteric, meaning they do not ripen further once picked. They are, however, extremely sensitive to the ethylene produced during storage. A high accumulated Ethylene concentration causes the stems to drop, the peel to turn a dull yellow and the vitamin C content to fall. The store's ventilation system must therefore be designed to purge 2-3 times a day, keeping the ethylene concentration below 1 ppm.
The 4-step process for preparing oranges before they enter the store
Putting oranges straight from the orchard into the store without preparation spreads disease and mould through the whole batch.
Step 1: Harvest at the right ripeness and grade for sale
Oranges should be harvested with proper secateurs once the peel is at least two-thirds ripe. Any fruit that is scratched, bruised or showing signs of disease is then removed, to avoid cross-contamination in the cold room.
Step 2: Wash and treat with a 1% sodium hypochlorite solution
The oranges are washed under clean water spray, then dipped or misted with a 1% sodium hypochlorite solution for 2-3 minutes. This step destroys the fungal spores and bacteria on the peel.
Step 3: Wax the fruit to protect the peel
A thin coat of food-grade wax (such as Citrashine) is applied. The wax forms an artificial film that replaces the natural bloom lost in washing, cutting moisture loss to below 5% and giving the fruit an attractive shine.
Step 4: Pack in perforated film and ventilated cartons
Each orange is wrapped in a plastic bag pre-perforated with 2-3 small holes for gas exchange. The fruit then goes into matching perforated cartons stacked on pallets, so air from the evaporator can pass through the whole load unobstructed.
Equipment and specifications for a produce cold store dedicated to oranges
A cold store for fresh oranges is made up of three main parts — the insulated panel envelope, the compressor package and the control panel — with the airflow designed to be gentle so the fruit surface does not dry out.
Standards for insulated panels (PU/PIR) and the cold store door
The envelope uses EPS panels (density 15-20 kg/m³) or PU/PIR panels (density 40-45 kg/m³), 75 mm to 100 mm thick. The doorway (sliding or hinged) is clad in 304 stainless steel with an anti-condensation seal heater, keeping the store fully insulated from the outside.
Condensing units suited to the above-zero temperature range
The store uses an industrial condensing unit running in the above-zero range (chiller), from leading brands such as Bitzer, Copeland or Tecumseh. The ceiling-mounted evaporator is specified with a 4-6 mm fin spacing and an electronic expansion valve, so cold air diffuses evenly rather than blowing at high velocity directly onto the cartons.
Control panel and automatic temperature alarm system
The power panel is fitted with a microprocessor temperature controller (Dixell, Danfoss or similar), NTC sensors and safety switchgear. The system raises an automatic alarm by sounder or SMS when temperature or humidity moves outside the 3-8°C and 85-95% bands.
Price guide for designing and building an orange cold store at Tân Long (latest update)
Expense cold storage installation for storing fresh oranges ranges from 80,000,000 VND to over 140,000,000 VND, depending on the total store volume, the panel thickness and whether the compressor is brand new or reconditioned.
Cost of a small cold store (15 m³ – 30 m³) for growers
| Store volume (m³) | Estimated capacity (tonnes) | Compressor rating (HP) | Indicative turnkey price (VND) |
| 15m³ | 3.5 – 4 tonnes | 2.0 HP | 80.000.000 – 90.000.000 |
| 20m³ | 5 – 6 tonnes | 2.5 HP | 90.000.000 – 100.000.000 |
| 30m³ | 7.5 – 9 tonnes | 3.0 HP | 105.000.000 – 115.000.000 |
Cost of an industrial cold store (40 m³ and above) for exporters
| Store volume (m³) | Estimated capacity (tonnes) | Compressor rating (HP) | Indicative turnkey price (VND) |
| 40m³ | 10 – 12 tonnes | 4.0 HP | 125.000.000 – 135.000.000 |
| 50m³ | 13 – 15 tonnes | 5.0 HP | 140.000.000 – 155.000.000 |
| 100m³ | 25 – 30 tonnes | 10.0 HP | Contact us for a site survey |
(Note: the prices above are indicative only and may vary with material market prices. Contact Tân Long for an accurate quotation.)
Tân Long – a leading refrigeration contractor for produce cold storage
Tân Long (tanlongvn.com) has more than 20 years of experience advising on, designing and building cold stores for agricultural produce in Vietnam. Across hundreds of projects at fruit-growing centres in the Mekong Delta and the southeast, Tân Long's engineers commit to using 100% genuine equipment, calculating the heat load accurately and providing in-depth humidity control for commercial oranges. We offer a turnkey service from free site survey through to on-site warranty and maintenance for 12-24 months, so the system runs reliably and efficiently.
To get the most out of a Tân Long cold store, accurate installation is only part of it — the owner must also be alert to the operating risks that can cause losses across a whole batch.
Risks and mistakes that spoil oranges when running a cold store
Running the store incorrectly can ruin an entire batch of oranges even when the equipment is working perfectly. Here are the three most common mistakes:
Stacking too tightly and blocking the airflow: Placing cartons against the wall or in front of the evaporator fans obstructs air circulation. The shadowed corners never receive enough cold air, generate heat, and the oranges rot quickly.
Not setting up a regular defrost: Frost packing the evaporator reduces heat transfer, letting the store temperature climb above 8°C without the operator noticing.
Opening the store door too often: Going in and out frequently without a PVC strip curtain causes serious heat loss, leaving condensation on the fruit and creating ideal conditions for mould.
Frequently asked questions about storing fresh oranges in cold storage
Can oranges be stored with durian, bananas or mangoes in the same room?
Absolutely not. Oranges must never be stored with fruit such as durian, banana, papaya or mango. These climacteric fruits produce very large quantities of ethylene as they ripen. In the enclosed space of a cold store the gas reaches the oranges immediately, forcing them to ripen, softening the peel and substantially shortening their storage life.
How many tonnes of oranges will a 20 m³ mini cold store hold?
A 20 m³ mini cold store (internal dimensions of roughly 3 m x 3 m x 2.2 m) will hold a maximum of 5 to 6 tonnes of fresh oranges. The actual capacity depends on the carton specification and on stacking the pallets with enough space for air to circulate.
Which orange varieties (sanh, xoan, vinh) keep longest in storage?
Storage life depends largely on the biology of each variety. Cam sanh and Cam V2: a thick peel rich in essential oils and good disease resistance give these the longest storage life, up to 2.5 to 3 months. Cam xoan and cam mat: a thinner peel that loses moisture more easily, so safe storage is usually 1.5 to 2 months under ideal conditions.
What is the difference between a fixed cold store and a reefer container?
Criterion Fixed cold store (built by Tân Long) Reefer container Capital cost Better value at larger volumes, from 80 million VND Higher, with the cost of renting or buying the container Temperature stability Extremely stable, thick panels, separate compressor easy to maintain Less stable when left in strong sunshine Flexibility Installed permanently at the buying centre or plant Easily moved, suited to sea and road transport A fixed cold store suits large buying centres that need to hold goods for long periods, while a reefer container works better for moving and exporting goods through border crossings and seaports. See also: Ice cold storage: construction and applications Seafood cold storage: design and installation pricing to standard Restaurant cold storage: choosing, designing and installing to F&B standards
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Kỹ sư Nguyễn Toàn Thịnh (Giám đốc Kỹ thuật)
Hơn 18 năm kinh nghiệm thực chiến chỉ đạo tư vấn thiết kế và thi công hệ thống lạnh công nghiệp nặng, kho tự động ASRS và cấp đông IQF qua hơn 29 đại dự án quốc gia.
