Sr. No	Infrastructure	Components	Remark
1	Packhouse	Sorting, cleaning, grading, packing, precooling, staging or ripening	At production centre.
2	Cold Storage	Receiving, holding, maintain quality and delivery	Within vicinity of production clusters.
3	Multi commodity multi chamber cold storage	Receiving, holding, bulk breaking, distribution	At consumption centre.
4	Logistic / Transport	Different temperature for different nature of commodity.	Temperature-controlled, insulated and frozen vehicles entire supply chain.

Cold chain infrastructure projects are easier said than done. Therefore, each component of cold storage needs to be selected very carefully, either the structure of building, machine or insulation part of the project. The current practices followed in cold storage infrastructure are discussed as under:

Building - Earlier civil building used to be a part of cold chain infrastructure, however, the same has been replaced with pre-engineered building (PEB). The PEB can be installed above wall of certain height or plinth level as per the requirement. In case of pack house, it better has wall with tiles on it, to maintain the cleanliness in the premises.  Also, an epoxy coated floor would be better option instead of other flooring option. Epoxy floor will help in proper cleaning and maintaining hygiene in the area.
The height of the PEB can be raised more than 15 m. This is an advantage for the PEB that when there is a space constraint to match the desired capacity the building height can be increased till the requirement, subject to height permission and FSI norms of particular location.

Another advantage of having pre-engineered building in cold chain like project is that, these steel structures take 40% to 45% less time for installation as compared to construction of civil work. The time saved will give chance to generate revenue from the project. In case of civil work, the demolition cost is required and cannot be used as the demolished component, however in case of steel building, the unit can be easily dismantled and can be shifted at new place or can be sold in scrap too. In terms of cost, both civil and steel work will be similar, steel work could be sometimes below, as steel rate in market keeps on fluctuating.

Insulation - Earlier days in civil infrastructure project thermocol used to be placed in between thin metal sheet and brick wall. However, such type of insulation is not durable and needs to keep on replacing as and when required. Therefore, in modern cold storage project PUF panels are being used.

PUF panels are lightweight, energy-efficient and durable panels. Suitable for diverse applications, PUF panels consist of a rigid core sandwiched between sheet metal structural boards. PUF insulated sandwich panels integrate joists and studs, insulation, vapour and air barriers. PUF panels acts as wall to the steel structure and insulated material for cold storage. The width of PUF ranges from 40mm to 150mm used in cold storage projects.

Capacity - In modern cold storage projects will be beneficial if the same being setup near consumption centre. As there would be a requirement of mixed kind of product range. Generally, in modern cold storage the chamber size is small, as multiple products would be required to store, which leads to multiple temperature requirements too. Therefore, so as to match their temperature requirement and which also reduces the utility cost small size multiple chambers are generally proposed. As per the National Horticulture Board, such projects should have capacity of 250 MT/ chamber.

The product which is going to be stored must have removed field heat, if received from field. Each product one handles has its own temperature requirement after harvesting at farm. However, when the temperature of harvested produce is reduced within four hours of harvesting by means of pre-cooling or any other way of it, the following changes can be achieved - Decrease in respiration rate; - Reduction in water loss; - Sensitivity of ethylene is reduced; - Microbial development is slowed.

Sr. No	Temperature Zone	Temperature Range	Products Stored
1	Frozen	-5°C to -40°C	Processed food (Frozen, Blast or IQF)
2	Chilled	+0°C to + 5°C	Apple, Orange, Pear, Grapes, Carrot tc.,
3	Cold/ Cool Storage	+8°C to 15°C	Processed food
4	Ambient Storage	+15°C to 25°C	Chocolate, Powders etc.

Material handling - Generally, this has been observed in modern cold storage infrastructure that, the material is being placed on the pallet and the pallets on the steel racks. the height of each shelf of rack would be kept maximum is 1.50 metre and which holds load up to 750 to 1,000 kg material subject to volume of the product. The height of racking can go up to 10 heights vertically. The standard size of pallet followed is 1,000 mm X 1,200 mm and 1,000 mm X 1,300 mm. The types of pallet racking system have range of mobile racking, stationery racking and drive in racking system. However, mobile and drive in racking is not seen personally anywhere but stationery has been seen at many places. Stationery racking could be single deep or double deep. The material moment in rack based cold storage units is done through the rich tricks, which can lift loaded material till 15 metre height and can extend its fork 2 metre. The turning radius of rich truck is 3.20 metre, therefore in case of stationery racking distance between two racks would be minimum of 3.20 metre.

However, in single product like potato storing cold storage, the capacity can be of 1,000 MT / chamber or more than that. In single chambered or big chamber sized modern cold storage infrastructure, potatoes are directly loaded in chamber in loose condition through extendable loader conveyer till the desired height and stored for long time.

However, in case of old infrastructure single commodities are stacked on mezzanine floor in the cold storage. Mezzanine floors are not permanent structure, but have load bearing capacity to handle the load of stacked material. Such floors have made up of wooden or mental strips placed at desired distance, which helps in circulating cold air throughout all floors.

Major refrigeration components
Thermostatic Expansion Valve - Before the evaporator, this is located at the end of the liquid line. This is a device that controls the amount of refrigerant that flows to the evaporator.

Evaporator - The sole purpose of the evaporator is to remove the unwanted heat from the product through liquid refrigerants. The liquid refrigerant must be at a low pressure.

Capacity Control System - As its name might suggest, the capacity control system regulates the power and energy consumption, although it can also manage dehumidification or decrease compressor cycling. The on/off cycling of the compressor is the simplest form of capacity control.

Compressor - In simple terms, a compressor can convert low-temperatures to high-temperatures, which can be the cause of an increase in pressure. Through a compressor, heat can be easily released.

Condenser - This device can extract heat from the refrigerant. Fans placed above the condenser unit draw air over the condenser coils.

Receiver - As a temporary storage and a surge tank for liquid refrigerant, the receiver acts as a vapour seal. With a primary purpose of preserving the vapour moving down the liquid line to the expansion valve, receivers can be made for both horizontal and vertical installation.

(The author is dy VP and project management consultant for food processing and cold storage at ITCOT Consultancy and Services Limited, Mumbai. He can be contacted at chidrawaramol@gmail.com)