Shipping Containers Blog

Posts Tagged ‘reefer containers’

Refrigerated Containers, sometimes known as reefer containers, are shipping containers designed to hold goods in a temperature controlled environment. This can be set anywhere between -20C to +20C. As such a refrigerated container is suitable for a variety of goods ranging from fresh produce (chill controlled), ice cream (hard frozen) to explosives and chemicals (temperature controlled). All controllers on refrigerated containers have a display that will show the set point and running temperature.

It is important to site a refrigerated container on level hard standing. The weight of the container’s insulated doors mean that unless the unit is sited correctly the doors are likely to be hard to open and may even get a build up of ice behind the door seals, effectively freezing them shut.

A refrigerated shipping container is designed to maintain the temperature of the goods placed inside rather than to blast freeze them. For maximum efficiency the products should be stacked a foot away from the front panel (which is the end opposite the doors!) and be a foot below the ceiling for maximum efficiency. This allows the airflow to pass under the product (through the t-bar flooring) and up by the doors, before passing over the top and back down again. Refrigerated containers are designed to maintain the temperature of the goods placed inside rather than to blast freeze them.

Most reefer containers normally have a Partlow to record the temperature that the unit is running at. Some controllers even have the facility to download information via a laptop equipped with the appropriate software programme. It is also possible to attach a system which, should the unit drop below the set temperature, a call is generated to a phone (mobile or land line) by way of warning so an engineer can be called out promptly to fix the problem.

In order to keep the reefer container running efficiently it is a good idea to defrost (remembering that this defrosts the machinery and not the product stored inside) once or twice a day. A service is recommended every 6 months but this does depend on where the unit is sited as dirt/dust will affect the operation of the unit if not cleaned out regularly. For example, if you are putting the refrigerated container in a dusty environment you may need to service your container more regularly in order to stop it from becoming clogged. The servicing interval can also be dependent on the temperature the unit is running at - chill is less work for the machine than freezing for example.

Refrigerated Containers can be adapted in a variety of ways. Lights, internal alarms, emergency stop buttons, butchers or caterers doors are all commonly installed conversions. Solid checker plate flooring is also popular - particularly when the products are going to be store at temperatures above +0C.

T-bar floors are often thought to be less desirable than checker plate in a refrigerated container. They are considered difficult to walk on and to keep clean and there advantages overlooked. It is important to remember that these containers were designed as shipping containers that could keep cargo in a temperature controlled environment whilst in transit. The original containers came with t-bar floors and there are a number of good reasons for that.

refrigerated container with t-bar floor

Truth is t-bar floors have lots of different advantages as far as keeping the contents of the reefer containers chilled or frozen. The main one is how the t-bar floors design helps air flow. The profile of the floor allows for the chilled/frozen air to travel around the container from the refrigeration unit underneath the contents. This means that the unit works to maximum efficiency in terms of economy and effectiveness. Providing the contents are packed so that there is space to the sides and top of the container the air flow can continue to travel round unimpeded.

One criticism that is often levelled at t-bar flooring is that it is difficult to load pallets using anything with wheels! A very simple and cheap solution can be taken by following the example of supermarkets. They lay a piece of plywood onto the floor for the wheels to travel over. It is simply removed when the reefer container is loaded.

Like all containers used for food storage it is important that refrigerated containers can be kept clean. The steel sides and the t-bar floor are the original features and respond well to being jet washed. Unlike checker plate flooring it is difficult for food to stick to a t-bar floor.

Obviously, there are times when a t-bar floor is not going to be the answer. It would not be the best choice for a food preparation area for example. But for the original purpose of a refrigerated container - to keep food chilled or frozen - it is hard to beat.

PR: wait… I: wait… L: wait… LD: wait… I: wait… wait… C: wait… SD: wait…

We have been discussing refrigerated containers on this week’s blog and quite a few of you have rung the office with questions which I thought would be a good idea to answer here.

How is the temperature recorded on a refrigerated shipping container?

On marine units the controller will have a display that will show the set point and the running temperature.  If particularly required some units have displays which can also be “downloaded” - whereby you can see a set of parameters over a set period of time although you will need additional equipment in the form of a laptop,  specialised software etc.  Other units have a Partlowchart (like the taco graph that some lorries have) although it is important should you wish to use them you specify this to your supplier at point of order.

How should a refrigerated shipping container be loaded for maximum efficiency?

The products inside te container should be stacked at least a foot away from the front panel (which is the end opposite the doors!) and at least a foot away from the ceiling. This allows air to flow under the product (through the t-bar flooring) and up by the doors before going over the top of the goods and back down again.

Can I use a refrigerated container to bring things down to temperature?

A refrigerated container is designed  to maintain the temperature of the goods placed inside rather than bring the goods down/up to the set point temperature like a blast freezer.

Tomorrow we will deal with some of the more challenging technical questions to do with electricity supply and servicing that some of you seem so keen to know about - our electrician has been relentlessly quizzed and come up with some understandable answers to your questions.

Refrigerated Shipping Containers are available in a variety of different sizes and I have been asked to list the dimensions of them so that readers can get a clear idea of what they need.

POWER SUPPLY: 3 Phase, 415-460 volts. 32 Amp per phase, motor rated supply
POWER CONSUMPTION: 5.5kw @ -18C Frozen, 7.2kw @ +2C Chill
All used Reefer Containers sold in Wind & Watertight condition.

All refrigerated containers vary slightly in their actual dimensions but the above table gives a good general guide to base your calculations on.

Popular models of refrigerated shipping containers include carrier, thermoking, daikin and mitsibushi. Parts for these are readily available in the UK.