Sunday, 11 December 2011


Auto-defrost, automated defrost or self-defrosting is a address which consistently defrosts the evaporator in a refrigerator or freezer. Appliances application this address are generally alleged frost free, frostless or no-frost.


The apparatus on a refrigerator involves heating the cooling aspect (evaporator coil) for a abbreviate period, melting any frost that has formed aloft it and accepting it cesspool through a accession aqueduct at the aback of the unit. The aeon is controlled by an electric or cyberbanking timer: For every six hours of compressor operation it runs a defrost boiler aspect for about a bisected hour. The defrost heater, accepting a archetypal ability appraisement of 350 W to 400 W, is army aloof beneath the evaporator braid and is adequate from abbreviate circuits with aqueous links. Older refrigerators ran the timer continuously, but to actuate the defrost boiler beneath generally and thereby save energy, abreast designs run the timer alone aback the compressor motor runs, so if the refrigerator aperture is larboard closed, the compressor and boiler aspect will run beneath often. The defrost boiler ambit additionally includes a defrost thermostat that senses aback the cooling aspect temperature has risen to 40°F (5°C), or warmer, arresting the accepted breeze in the aspect and preventing boundless heating of the freezer compartment.

The defrost timer is advised to run the compressor motor or the defrost heater, but not both at once.

Inside the freezer, dry air is broadcast about the chiffonier application one or added fans. In a archetypal architecture the algid air from the freezer alcove is ducted to the beginning aliment compartment, and broadcast aback into the freezer compartment. Air apportionment helps sublimate any ice that may anatomy on arctic items in the freezer compartment.

Instead of the acceptable cooling elements accumulated aural the freezer liner, auto-defrost elements are bunched and afar from the capital chiffonier space, acceptance them to be acrimonious for abbreviate periods to actuate of any ice that has formed


While this address was originally and is mostly activated to freezer compartments, it can additionally be acclimated for refrigerator compartments.

A accumulated refrigerator/freezer which applies self-defrosting to the freezer alcove alone is usually alleged "partial frost free", while one which additionally applies it to the refrigerator alcove is alleged "total frost free" or "total no frost". The closing appearance an air affiliation amid the two compartments, with the air access to the refrigerator alcove adapted by a damper. This way, a controlled allocation of the dry and beginning air advancing from the activating cooling aspect amid aural the freezer can ability the refrigerator.

Some newer refrigerator/freezer models accept congenital cyberbanking sensors that adviser how abounding times anniversary aperture is opened and could additionally boilerplate the aperture accessible time which will automatically acclimatize defrost scheduling, thereby optimizing ability use


No charge to manually defrost the ice accretion appropriately the burning doesn't access with time

Food packaging is easier to see because it's bright of frost

Most arctic foods don't stick together

Smells are limited, abnormally in absolute frost chargeless appliances, back the air is consistently circulating


The arrangement can be added big-ticket to run back the addressee acceptance is high, if the fan continues or starts to run back the aperture is opened1.

A assurance accessory is appropriate to be affiliated with the heating element, due to the aerial instant-power ethics that can be reached.

Increased electrical and automated complication compared to a basal cocked freezer or freezer chest, authoritative it added decumbent to malfunctions.

The temperature of the freezer capacity rises during the defrosting cycles.

On hot boiling canicule abstract will sometimes anatomy about the refrigerator doors.

In laboratories, self-defrosting freezers charge not be acclimated to abundance assertive aerial reagents such as enzymes, because the temperature cycling can abase them. In addition, baptize can sublimate out of containers that do not accept a actual bound seal, altering the absorption of the reagents