Refrigerator's Air Circulation and Humidity

Read Review On Refrigerator's Air Circulation and Humidity

The refrigerator relies on forced air to replacement heat. Fans inside the appliance move air around. The faster the air flows, the more swiftly the heat is removed. For this reason, you don't want to do whatever to block the airflow. There are three basic types of forced-air systems in refrigerators. In ceiling-type refrigeration,
a singular fan is mounted on the ceiling of the appliance. This is enough for small-volume interiors but is not used in larger refrigerators. Because it only has a singular location, it might allow for hot spots in the corners of the interior cabinet. In back-wall or mullion-type refrigeration, the airflow theory takes in air above the top shelf and discharges it below the lowest shelf.

The duct-type refrigeration theory is a composition of the first two types. Here, the forced-air unit is settled at or above ceiling level, and the air is circulated through a series of small air ducts vented to discrete spots on the back wall of the cabinet. Just how foremost is air circulation? Well, the variation between safe and unsafe raw foods can be as tiny as five to seven degrees Fahrenheit. Seafood, poultry, or red meats will spoil within 18 to 24 hours if their refrigerated climatic characteristic rises above 42 to 45 degrees
Fahrenheit, and you already know the Haccp guideline of temperatures no higher than 40 degrees Fahrenheit. Would you rather risk a lawsuit and the resulting negative publicity from food-poisoning allegations, or keep your refrigerator air circulating properly?

Humidity is the number of moisture (or water vapor) in the air. At separate temperatures, air can hold separate amounts of water. In refrigeration, the type of humidity we are interested in is the relative humidity, or how much of its maximum water-holding capacity the air contains at any given time, expressed as a percentage. For example, 85 percent humidity indicates that the air is retention 85 percent as much water as it could hold at that temperature. Relative humidity greatly affects the appearance and rate of deterioration of many foods. If the air surrounding the stored foods has a very low relative humidity, for instance, the air simply picks up moisture from the foods themselves, causing outside discoloration, cracking, and drying.

If the air has a high relative humidity, some of the moisture will dehydrate on food that is supposed to be kept dry, causing it to soften or grow mold or bacteria. Fortunately, most foods do well in a relative humidity of 80 to 85 percent. To achieve this optimum level, manufacturers are implicated that the refrigerator's evaporator coils be large enough to operate at a climatic characteristic a few degrees lower than the desired climatic characteristic of the appliance. This differential reduces the number of moisture that accumulates on the evaporator coils and keeps the moisture in the cabinet of the refrigerator instead. If the coils' climatic characteristic becomes too low, however, the moisture will turn to ice crystals and get stuck on
the coils.

In this case, airflow through the theory is blocked and the moisture in the refrigerated space is depleted. As you can see, getting all the factors right is a delicate balance, with your food costs and food potential at stake. In short, it is difficult to keep frost off the coils but needful to keep them frost-free so they will operate properly. Adding heat to the area, to defrost the coils, can compromise the climatic characteristic of the food inside. A fairly new belief from Hussman Modular Defrost of Bridgeton, Missouri, does just what its name indicates: defrosts the coil in sections. The automated theory defrosts coils at no more than nine minutes per section, and never defrosts adjacent sections at the same time, all programmed by an electronic controller capable of running up to six walk-ins.

The idea works for walk-in and reach-in refrigerators but not freezers. It maintains food potential and saves power by retention the compressors from working overtime to compensate for icy coils. Another humidity-control hint for inside refrigerated space was pioneered by Humitech International Group, Inc. Of Dallas, Texas. Humitech uses a mineral stock called sorbite to suck in moisture and odors.

We mentioned most foods do well at 80 to 85 percent relative humidity, but fresh fruits and vegetables are exceptions. They want more humidity, up to 95 percent. To increase moisture content, you can slow down the air circulation. This explains why there are separate, finished produce bins in most refrigerators-to hold in natural moisture from the vegetables and to restrict airflow.

Freezers utter an midpoint relative humidity of only 30 to 35 percent. Any more moisture would automatically raise the climatic characteristic because it would hit the coils, frost in place, and block the airflow, causing the freezer air to come to be warmer. The low humidity of freezers requires special food storehouse precautions. Use moisture- and vapor-proof wrapping to preclude the outside damage we know as "freezer burn" from occurring if any moisture condenses on the food.