Frost Free refrigerator is a cooling machine for the household, office or business. It’s different from the classic refrigerator in that, ice doesn’t cover stuff you store in the freezer.
Frost free refrigerator is also known as a non-frost or no-frost refrigerator. Its technology preceded the conventional direct cool refrigerator. A direct cool system builds frost on the inner surface of the freezr compartment.
Both technologies are, however, available in the market for you to chose.
A typical frost free refrigerator has three main system components. The compressor, condenser, and evaporator. The system has other complementing control gadgets that do automatic defrost. They are the evaporator fan, defrost heater/element, thermal switch, and timer switch.
We have analog and digital timers in the industry. But I’m using the analog timer for explanation in this post.
If you open your no-frost refrigerator’s freezer compartment door, all items inside look clean and not covered with ice. But in a direct cool refrigerator, it’s common to see stuff covered in ice, and freezer compartment’s inner wall covered with a thick layer of ice. Sometimes you need to defrost the freezer to be able to take out stuff.
How the gadgets work in your frost free refrigerator
As the compressor runs, the refrigerant uses up the little heat that’s around the evaporator to boil. The resultant effect is low-temperature air around the evaporator. Continuously, the evaporator fan stirs up the cool air left around the evaporator to all the spaces in the compartments.
After a no-frost refrigerator has run for 24 hours or more, frost builds up on the evaporator. The thermal switch, which senses the cold evaporator surface temperature, closes, to connect the heater. The timer switch puts off the compressor and turns on the heater for defrosting. The heater melts ice on the evaporator, and the molten ice(water) flow down a drain pipe.
The timer switch has set duration before it cuts off electricity to the heater. Between 20 minutes to one hour. But if the defrosting completes before the timer’s set time, the thermal switch senses high temperature and opens, to disconnects the heater.
The extra gadgets push a no-frost refrigerator’s buying price a little higher than a direct cool’s, though.
In comparison with a direct cool system
In a direct cool refrigerator, the evaporator tubing is run behind the wall of the inner refrigerator surface. That’s why when the refrigerator is functioning, you see it form a layer of ice on the inner walls of the freezer compartment.
After days of operation, it’s common to find that ice covered the stuff you kept in the freezer compartment. To remove an item from the freezer compartment, you may need to first defrost the freezer compartment.
This frost build-up in the freezer compartment eats up space in the compartment. Also, the layer of ice impedes efficient heat transfer from items that need cooling to the refrigerant in evaporator tube.
Furthermore, the process of defrosting an ice-covered direct cool refrigerator takes time. You may need to switch off the refrigerator and open the freezer door to let warm air flow in to melt the ice. But if you have an urgent need for an item from the freezer, you’d have to bear with the delay.
The tedious manual defrost process is one of the reasons that informed the research and development of no-frost technology.
Self-defrost was a positive step in refrigeration technology advancement. But it never failed to spark controversy. In the advent of frost free technology, critiques speculated that it caused freezer burn. Freezer burn is the unpleasant effect on food(especially meat) you keep in a freezer. If it’s exposed to air, it dehydrates and oxidizes. The color of the meat turns and its texture changes, affecting its original taste.
The truth is, no-frost technology has nothing to do with freezer ban. To avoid freezer burn, package your meat in a recommended airtight packaging bag. Remove all the air in the packaging before placing inside the freezer. Poor packaging allows air into the bag and facilitates dehydration and oxidation.
From the consumer insight, 99.99% of users who’ve had a taste of a direct cool refrigerator, and are now on frost free, are happier.