Refrigerator’s Air Circulation and Humidity

Refrigerator depends on forced air to transfer heat. The fans inside the refrigerator move the air around. Removing the heat also relies on the air flows. Because of this there should be anything inside that can block the circulation of air.

There are three basic types of forced-air systems in our refrigerators. They are the following:

Exclusively adequate for small-volume interiors and not for larger refrigerators, the ceiling-type refrigeration has a single fan mounted on its ceiling. Due to a single location, hot spots in the interior cabinet particularly in the corners might produce hot spots undesirable for its operation. This is not the case for mullion type refrigeration where intake and exhaust are available on both ends.

Mullion means the division between panels; it is the panel between the doors that become cold. Combining these two types, the duct-type refrigeration system has taken advantage of the combined features. Circulation is not an issue. This type of refrigeration has strategically positioned its forced-air unit at or above ceiling level. Now, the hot air circulates through a series of small air ducts with ventilation to various spots on the back wall of the cabinet.

Circulation plays vital importance in refrigeration system. Consider for instance a raw food; the working functionality of refrigerators will dictate how safe our food will remain especially for raw foods which freshness varies roughly about 5-7 degrees Fahrenheit. Thus, an increase of temperature beyond 42 degrees will spoil seafood, poultry, or red meats. That said, keeping refrigerator air circulation properly will ensure to eliminate undesirable feedback or worse non compliance with HACCP guideline of temperatures that could result to bad publicity.

Another factor for keeping a good refrigerator circulation is ensuring that evaporator coils are large enough to withstand a temperature lower than the acceptable temperature of the appliance. This is important to eliminate the possibility of the food to soften or grow mold and bacteria when there is high relative humidity in the environment which causes moist to condense a supposed dry food. This gear’s main purpose is to ensure that the moisture content that forms on the evaporator coils are reduced and kept in the cabinet of the refrigerator. Nonetheless, it is not ideal for the coils’ temperature to become too low as it would transform the moisture into ice crystals and immerse on the coils. This makes the airflow within the system contained and the moisture in the refrigerated space diminished.

For refrigeration system to function desirably, it is really important to sustain delicate balance of air circulation especially when cost and quality of food is at stake. Hence, though keeping frost off the coils may be complex, it is of utmost importance to keep them zero frost to ensure 100% workability. Natural heat on the environment to defrost, can impact the temperature of the food inside.

Hussman Modular Defrost of Bridgeton, Missouri introduced a concept that aims to defrost the coil gradually. It involves an automated system which defrosts coils at less than nine minutes per section, and never frost-off alongside sections simultaneously. This concept works for both regular refrigerators walk-in and reach-in but without freezers. By keeping the compressors non-stop to make up for frozen coils, the quality of food and efficiency of energy are maintained.

Humitech International Group, Inc. of Dallas, Texas introduced another concept which aims to control humidity for inside refrigerated space. They use a mineral product called sorbite to absorb moisture and odors.

Except most food, fruits and vegetables don’t sustain its freshness at 80 to 85 percent relative humidity. They require more humidity, up to 95 percent. Slowing down the air circulation is performed to increase moisture content. This is why most refrigerators have dividers to ensure that desired airflow is contained on sections where it is desired.

In the coolest section of a refrigerator, the freezers, an average relative humidity of less than 35 percent is maintained. Anything beyond this would instantly raise the temperature as it would touch the coils. Special food storage is required for freezers due to its low humidity.