The actual process air conditioners use to reduce the ambient air temperature in a room is based on a very simple scientific principle. The rest is achieved with the application of a few clever mechanical techniques. Actually, an air conditioner is very similar to another appliance in your home; the refrigerator. Air conditioners don’t have the exterior housing a refrigerator relies on to insulate its cold box. Instead, the walls in your home keep cold air in and hot air out.

Your air conditioning unit uses chemicals that convert from gas to liquid and back again quickly. These chemicals transfer the heat from the air inside your property to the outside air.

The AC unit has three key parts. These are the compressor, the condenser, and the evaporator. Your unit’s compressor and condenser are typically located in the outside part of the air conditioning system. Inside the house is where you will find the evaporator.

The cooling fluid reaches the compressor as a low-pressure gas. The compressor squeezes this gas/fluid, and the molecules in the liquid are packed closer together. The closer the compressor forces these molecules together, the higher the temperature and energy rise.

This working fluid exits the compressor as a high-pressure, hot gas, and it moves to the condenser. The outside unit of an air conditioning system has metal fins all around the housing. These fins work like the radiator on a vehicle, and they help dissipate heat more quickly.

When the fluid leaves the condenser, it is much cooler. It’s also changed from a gas to liquid because of the high pressure. The fluid makes its way into the evaporator through a minuscule, narrow hole and when the liquid reaches the other side of this passage, its pressure drops. When this happens, the fluid begins to evaporate to gas.

As this occurs, the heat is extracted from the surrounding air. This heat is required to separate the molecules of the liquid into a gas. The metal fins on the evaporator also help exchange thermal energy with the surrounding air.

When the refrigerant leaves the evaporator, it is once again a low-pressure, chilled gas. The process starts all over when it goes back to the compressor. There is a fan that’s connected to the evaporator, and it circulates air around the inside of the property and across the fins of the evaporator.

Installation, maintenance and repair of Residential Air conditioners

Large scale deployment of Air conditioners and cooling systems

In fruit and vegetable production, packing represents one of the final farm practices. In order to sell the crops as soon as possible and continue with other farm activities, some farmers preferably skip crop packing. When doing so, they usually sell their products in shipping containers without a special package. For some farmers, on the other hand, packing is an obligatory farm practice, essential for crop quality preservation, as well as marketing management. In response to this, packing can be a simple practice of moving the fruit into a shipping container or it can include a variety of post-harvest management practices.

A packing house is a facility where fruits and vegetables are received and processed prior to distribution to market.

Packing can be practiced on the farm, immediately after the harvest or later when the crops are delivered in a storage facility. Furthermore, packing can be practiced manually, or with the use of packing machines. The choice of adequate packing method will depend on the requirements of each crop production, as well as farmer’s financial possibilities and post-harvest management requirements.

Fruit & vegetable processing in a pack house begins with a process called dumping. It is a practice that includes moving the fruits from the bin or container to a packing house. The fruits can be delivered to a packing house manually, dumped on a conveyor belt or padded ramps. Besides that, the fruits can be dumped into the water for cleaning as shown in the picture above.

Several other processes such as sorting and selection, advanced cleaning, fungicide application and waxing are performed in a packing house depending on the type of produce being processed

Read a more detailed explainer on the processes that go on inside a packing house here.

Every cold room we build has a built-in compressor that does the bulk of the work. The compressor is part of a system that also includes a liquid/gas refrigerant and a heat exchanger. The entire system is sealed and under high pressure. The cooling cycle begins with the refrigerant, as a gas, moving through the compressor where it is constricted (compressed) considerably, thus raising its temperature and pressure. This hot gas then leaves the compressor and starts flowing through the line into the interior spaces of the cold room. That’s when the magic happens.

Hot gas coming in contact with the cooler temperatures of the line inside the cold room causes the gas to quickly contract and liquefy. Still under high pressure, the liquid refrigerant flows through the line and absorbs heat from the interior space, gradually getting warmer as it makes its way through the loop. The warming refrigerant eventually flows through a heat exchanger, a device that removes the heat before sending the refrigerant back to the compressor. The compressor then compresses the refrigerant and starts the whole cycle again.

Compressors do most of the work in keeping our cold rooms cold. But they cannot do it all alone. In order to minimize the amount of work they have to do and keep the temperature inside consistent, we use a special type of insulating material to line the walls of the cold rooms. The insulating material is a poor conductor of heat. As such, it helps to keep cold exterior spaces cold regardless of how warm it is outside.

The heat from exterior spaces will simply not carry through the insulation well enough to have a serious impact on interior temperatures. Maintaining consistent temperatures is also crucial in preventing condensation which can form on the inside of the unit which could lead to ice formation and even mold growth. Now you know how a cold room keeps things cold. If you are in need of a cold room give us a call.