Extra Features Of Freezer

A freezer or refrigerator is a cooling device to cool the various components to a temperature below ambient atmosphere. It consists of a thermally insulated mechanism to transfer heat from comparatively warm environment to the external atmosphere. The main usage of freezers is to store and preserve various eatables. The more distinct definition of a freezer would be a device which maintains a temperature below the freezing point of water. Therefore, freezers keep their contents frozen at around -18 degrees C.

Principle of Working

The working principle is based on the use of heat pumps. A circulating refrigerant enters the compressor as a vapor at boiling point. The vapor is then compressed and it exits as superheated vapor. The superheated vapor then enters the condenser which cools the vapor. The saturated liquid refrigerant then passes through the expansion valve where its pressure decreases abruptly. The cold and partially vaporized refrigerant travels through the evaporator tubes. A fan circulates room air across the evaporator tubes because of which refrigerant is totally vaporized. This way the heat is extracted from the air and cooling is achieved.

Extra features

1) Automatic defrosting: In refrigerator water-vapor condenses on the cooling coils as frost and build up a thick ice layer. This ice acts reduces the cooling efficiency. For automatic defrosting, a heater and thermostat are fitted around cooling coils. The cooling is switched off and heater turned on till the temperature exceeds the freezing point of water around cooling coils. This melts any frost formation and normal cooling process is resumed.

2) A power failure warning: This alerts the user by flashing a temperature display. The maximum temperature reached during the power failure may also be displayed.

3) A status indicator: It is used to notify the user the probable time to change the water filter.

4) A cooling zone: This mechanism allows cold air to be diverted to the refrigeration section to cool milk, juice or other eatables in the door shelf.

5) Temperature controller: This knob controls the temperature of the refrigerator according to the type of food-item stored and according to the external atmosphere. It also regulates the amount of cold air circulating in the freezer compartment or the compartment where food items are stored.

6) LCD: This LCD may be used to suggest to the user what types of food-items should be stored at what temperatures. It also indicates the expiration date of the stored food-item.