No Frost – advantages and disadvantages

On the modern market there are fewer and fewer refrigerators and freezers that require manual defrosting. Only the small single-chamber refrigerators of domestic production and a certain number of freezing chambers of different brands can be referred to this category.

If you are going to buy a two or three chamber refrigerator of average and large volume and exactly such models, as the results of market research report, are in the greatest demand you will certainly face such terms as “automatic defrosting system”, “No Frost”, “Frost Free” or “freezer”. Therefore let’s try to understand the operating principles of modern refrigerators and identify the advantages and limitations of each type of defrosting.

Everybody probably understands that it is impossible to do without defrosting the fridge at all: the very work of the compressor and cooling system in a fridge means that there is a buildup of snow or hoarfrost on the inner walls. The manufacturers solve this problem in several ways.

And the type – drip

Samsung RL-44 QEUS refrigerator

As you understand, manual defrosting is very rare for refrigerating chambers, they defrost automatically by “drop” or “wind” type, the freezing chambers only by “wind” type or manually.

Drip-type defrosting is used in the majority of modern refrigerators. In this case the evaporator is located on the rear wall of the refrigerating chamber sometimes it is built into the back wall to save the space, in this case it is called “sunk evaporator” . The function of the evaporator is to cool the rear wall of the refrigerator so that the hoarfrost frost residue forms only on this wall. When the compressor stops, the ice particles start to melt and the moisture flows down into the drain along special guide channels and from there into a special vessel tray located above the compressor.

The temperature in the compressor area is quite high to allow the moisture formed in the refrigerator to evaporate. That’s where the cycle ends, and then it happens again. The defrosting process is carried out gradually and unnoticed by the refrigerator users who can only notice at what stage of the defrosting cycle the refrigerator is in at the moment, this is indicated by the rear wall, namely whether it is frozen or covered with water drops. The frequency and duration of the defrosting cycles depends on the setting of the temperature regulator knob the temperature in the refrigerating chamber , the degree of loading of the fridge-freezer with the products and the ambient temperature.

And this type is very windy

The wind type of defrosting, as a rule, is called No Frost system. In the No Frost models the evaporator is taken out of the refrigerator compartment and concealed in the housing behind the rear wall of the refrigerator or in the housing above the freezer compartment. The refrigerator is additionally equipped with one or more fans that ensure continuous circulation of the cold air inside the interior. The fan blows on the evaporator, the air cools and blows around the interior of the refrigerator through special air ducts. The moisture formed in the course of refrigerator operation does not freeze on the walls as a layer of hoarfrost, but “settles” in the coldest part – the evaporator.

The compressor switches off periodically and the frost layer, with which it is covered by by that time, is defrosted by a small heater, after which the formed moisture evaporates again.

Both refrigerating and freezing chambers can be equipped with No Frost system, whereas only the refrigerating chamber defrosts by the drop-type mechanism.

With any type of automatic defrosting the refrigerator is undoubtedly a great time saver for the users. Of course, you cannot do without defrosting at all: no matter how modern your fridge is, it is recommended to make preventive cleaning of the inside surface of the fridge 1-2 times per year when you turn it off, but of course you will not have to scrape off the 10 centimeters “snowy caps” with the help of a knife and ruler as you did a decade ago.

No Frost is not that simple

What is the model to choose, what are the advantages and disadvantages of No Frost comparing to drop-type refrigerators??

Experts speak about No Frost advantages:

– More even distribution of cold air and, consequently, temperature throughout the refrigerated freezer compartment.

– Faster restoration of the temperature regime in the chamber after loading a large batch of products or simply opening the door more than once this has a positive effect on the quality of cooling and preservation of food, saves energy .

Both the first and the second opinion are confirmed by the results of special tests conducted by “Demand” magazine: the difference in temperature inside the refrigerating chamber equipped with the No Frost system does not exceed 1-2 degrees whereas in the refrigerators of drop-type it can reach 5-6 degrees from +2 on the lower shelves to +8 on the upper shelves . The temperature difference is even more considerable in freezing chambers without No Frost up to 7-9 degrees in contrast to 1-2 degrees when having No Frost .

As for the faster restoration of the temperature after opening the door, herein the refrigerator capacity plays a role in addition to the No Frost, which is determined by the number of compressors and the quality of the thermal insulation of the refrigerator walls that are becoming more and more perfect every year. At the same time, some experts express the opinion that refrigerators without No Frost keep the temperature longer in case of power failure due to the absence of air ducts, through which cold air can leak.

Among the disadvantages of No Frost are called:

– The lowered level of humidity in the chambers due to the permanent forced air circulation and, as a consequence, the faster “drying out” of the foods.

– The reduction of the refrigerating chamber volume due to the additional equipment it is estimated, for example, that No Frost “takes away” at least 20 l of the useful volume of the freezing chamber .

– Higher noise level during operation simultaneous work of the compressor and ventilator plus the constant air mass flow .

– The increased power consumption during the refrigerator operation.

– Higher refrigerator cost, determined by the more complicated structure of the refrigerator and the presence of additional equipment for example, fans .

In our opinion the opinion about faster “drying” of foodstuffs in refrigerators with the No Frost system should not be the determining one: there are preconditions for faster “drying” of foodstuffs, but only if the rules of food packing are not followed during the storage.

The research conducted by the specialists of the “Demand” magazine showed, for instance, that the green salad leaves in both types of freezers start to wither already on the second day if they are not wrapped in the wet cloth. The same applies to the storage of cheese, meat, dairy products, fruit and vegetables. Practically the same moisture loss is also noted in special tests on “test packs”.

The data on the higher noise level of refrigerators with the No Frost system have been confirmed: Thus, while the standard two-compartment refrigerator operates on average at 42 dB the noise level of the refrigerators fitted with the No Frost system is on average 45-47 dB. At the same time, some manufacturers for example, Siemens use fans of improved design “low-speed” , in which case the noise level does not exceed the average class level.

Refrigerators with No Frost are really a bit more expensive than their “drop-in” counterparts, moreover the presence of many additional elements increases the probability of the product failure due to the breakage of one of the elements of its construction.

At the same time equipping the fridge with No Frost system increases its class and as a rule models with No Frost are positioned by the manufacturer as representing middle and high price categories, which increases the possibility of using improved technologies and having additional functions.

It should be noted that some refrigerators have a combination of a “crying” evaporator in the refrigerator compartment and a fan in the freezer compartment. Such a combination is quite attractive from the point of view of complex problem solving, especially along with the use of modern cooling technologies by most manufacturers.

These include, for example, multi-flow systems Multi Flow, Multi Air Flow, Super X-Flow, etc. , EcoFlow or EcoFlow systems.d. , door cooling systems, availability of supercooling mode, etc.p. And whether it is necessary for you to equip your fridge with the No Frost system or not, you can decide for yourself, because now you are fully equipped for it.

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