Cold Storage for Agricultural Produce

An agricultural cold store is a system for storing vegetables, fruit and post-harvest produce, operating at 0°C to 10°C with relative humidity controlled in the range of 85% to 95%. Tan Long designs and delivers turnkey chill rooms and agricultural cold stores for cooperatives, packing houses and processing plants nationwide.

Why produce needs its own cold store rather than sharing a freezer store

Installation process for cold storage wall and ceiling insulation panels. — PU/PIR panels are assembled using Camlock fasteners for a tight seal, ensuring maximum heat loss prevention.

After harvest, vegetables and fruit are still living tissue — they continue to respire, transpire and ripen. The storage problem is not to freeze them solid but to slow that living process down without causing damage.

This is the fundamental difference from a seafood or meat freezer store. Chilled too deeply, many tropical fruits such as mango, dragon fruit and banana suffer chilling injury — pitted skin, internal browning, loss of flavour — even without freezing. Conversely, if the humidity is too low the goods wilt, lose moisture and lose saleable weight.

Three factors to control at the same time

SCADA system monitor for intelligent refrigeration system programmed by Tan Long. — The SCADA software monitoring interface displays temperature and pressure parameters in real time, 24/7.

Temperature — 0°C to 10°C depending on the product group. Each type has its own threshold, and the chilling injury threshold of tropical fruit is much higher than that of temperate vegetables.
Relative humidity — 85% to 95%. A factor a freezer store need not worry about, but one that determines weight loss in a produce store.
Air circulation. Air has to reach the whole mass of goods to carry away respiration heat, but gently enough not to dry the surface.

Controlled atmosphere for high-value fruit

For products that need long storage or are shipped to distant markets, controlled atmosphere technology extends the storage life by a further 30% to 50% compared with an ordinary cold store.

The principle is to lower the O₂ concentration to 2% to 5% and raise CO₂ to 3% to 8%, slowing the respiration of the fruit. This solution suits products valuable enough to justify the additional investment in the gas control system.

Ethylene — the factor most often overlooked

Many fruits produce ethylene as they ripen, and the gas makes sensitive products around them ripen and age faster. Bananas are a strong ethylene source, while leafy vegetables and flowers are highly sensitive to it.

A mixed-product store therefore needs separate chambers by product group rather than one shared space — a detail usually overlooked at design stage and paid for in losses over the whole life of the store.

The investment case for cooperatives and packing houses

For produce, a cold store is not only a technical item but a price negotiation tool. Without one, goods have to be sold as soon as they are harvested — exactly when the whole region comes into season and the price is at its lowest. With one, the business controls when it sells and can reach more distant markets.

The scale of the investment should be calculated from the output per crop and the price difference between peak and off season, not from the land available. With a small output, it is possible to start with a container cold storage or a medium-capacity panel store and expand gradually.

The delivery process at Tan Long

Survey and heat load calculation. Establishing the product groups, output per crop, storage time, the temperature of goods at intake and the site conditions.
Chamber separation by product group. Separating strong ethylene producers from sensitive groups, and setting the temperature and humidity range for each chamber.
Refrigeration system and air flow design. Arranging the evaporators so that air reaches the whole mass of goods without blowing directly onto the product and drying it.
Equipment manufacturing at the plant. Tan Long manufactures the pressure equipment and the ancillary equipment for the system in-house.
Installation, commissioning and handover. The panel enclosure, cold storage door, the refrigeration system, control cabinet, together with operating instructions.

Reference configuration table by scale

Size	Temperature range	Humidity control	Suited to	Unit price
Small chill room	0°C – 10°C	RH 85% – 95%	Cooperatives, collection points	Contact us for a quote.
Packing house chill room	0°C – 10°C	RH 85% – 95%, separate chambers	Export packing house	Contact us for a quote.
Controlled atmosphere store	0°C – 10°C	RH controlled, O₂ 2–5%, CO₂ 3–8%	High-value fruit, long storage	Contact us for a quote.

The actual configuration and the quotation are settled after a site survey and a heat load calculation for the specific product groups and output.

Tan Long scope of supply

Chill rooms and agricultural cold stores, temperature range from 5°C to -40°C, capacity from 10 tonnes to 12,000 tonnes
Humidity control and air circulation systems tailored to each product group
Multi-temperature chamber separation within a single project
Manufacture of pressure equipment and ancillary equipment for the refrigeration system
PLC control cabinets, with remote temperature and humidity monitoring
Dedicated cold storage doors and a matched set of cold storage materials

Why choose Tan Long

Designed, manufactured and installed in-house. The equipment is manufactured at the Tan Long plant, which allows it to be built to the exact project specifications instead of forcing the project to fit off-the-shelf equipment.

More than 20 years in industrial refrigeration, with experience on projects up to 12,000 tonnes.

We understand the problem the grower and the packer face, not only the technical problem: the store has to help control when you sell and reduce losses, not merely keep things cold.

With seasonal produce, the biggest question is how long holding stock past the season still leaves a profit — see the analysis on holding produce past the season.

Frequently asked questions about agricultural cold stores

What temperature and humidity does an agricultural cold store need?

The common range is 0°C to 10°C depending on the product group, with relative humidity of 85% to 95% to limit weight loss from moisture. Each type of produce has its own threshold, so it must be set from the actual product list.

Why should produce not be kept in a freezer store?

Because vegetables and fruit continue to respire after harvest; the aim is to slow the living process, not stop it completely. Chilling too deeply causes chilling injury — pitted skin, internal browning, loss of flavour — particularly with tropical fruit.

What does controlled atmosphere achieve?

Lowering O₂ to 2% to 5% and raising CO₂ to 3% to 8% slows the respiration of the fruit, extending storage life by roughly 30% to 50% compared with an ordinary cold store. It suits high-value products held for a long time.

Can every kind of produce be kept in one store?

It is not advisable. Beyond the differences in temperature and humidity range, some fruits produce strong ethylene, which makes leafy vegetables and flowers age and wilt quickly. A mixed-product store needs separate chambers by product group.

Should a small cooperative invest in a cold store?

It depends on the output per crop and the price difference between peak and off season. With a small output, it is possible to start with a container store or a medium-capacity panel store and expand as the planted area grows.

Does Tan Long build cold stores at growing areas?

Yes. Tan Long surveys the output, the product groups and the actual site conditions, then proposes a suitable scale, delivering for cooperatives as well as packing houses and processing plants.