Frost Free Refrigerator Cooling Machine

Frost-free refrigerator
Kitchen frost-free refrigerator

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.

All the components work in harmony to achieve the temperature you desire. As a result, you don’t need to switch off your frost free refrigerator to defrost.

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.

Freezer burn

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.

Clean Your Refrigerator Fan-cooled Condenser

Condensing unit
Condenser and fan-motor

Clean your refrigerator fan-cooled condenser if it has gathered dust and dirt after months of operation. However, how often you clean it depends on the cleanliness of your environment air. A dusty enviroment means frequent cleaning.

Your refrigerator that has a fan-cooled condenser will work perfectly within its designer’s parameters when it’s new. But over time, its efficiency decreases. The amount of electricity it runs on to cool the same amount of stuff you pack in it increases.

The reason is because dust and dirt gradually cover the fan-cooled condenser tube. This hinders normal heat exchange that happens at the condenser.

In this article, you learn the few simple steps of how to clean your refrigerator fan-cooled condenser.

How the government protect consumers

For a start, the Federal Trade Commission sets energy standards to protect the consumer interest. Manufacturers must place Energy Guide and Energy Star Labels on their electric consumer products. The labels inform the consumer that the said appliances are compliant. So, a compliant appliance should run on the government’s (Bureau of Standardization) recommended minimum electricity.

If you’re planning to buy a refrigerator appliance, and electricity consumption is a concern, check the labels to verify that it’s compliant.

Condenser

Condenser tube (refer to the main photo above) is the refrigerator’s external heat exchanger. At the condenser, refrigerant dumps heat it collects from inside the refrigerator. This happens in the process called the refrigeration cycle.

The fan enhances heat transfer by blowing low-temperature air across the condenser fins. Besides, it removes the heat that the compressor and condenser dissipate.

Condenser tube’s outer surface should be clean and free from dust in order for it to allow efficient heat transfer. However, the air that moves across the condenser carries fine dust and dirt that sticks on the condenser tube surface. This gradually forms a layer of dust insulation that impedes heat exchange.

So, if the refrigerator isn’t completely broken down but cooling ineffectively, clean your refrigerator fan-cooled condenser.

Although calling in a qualified refrigerator technician would be your first option, a few DIY can save you bucks.

Let’s use the G420 showcase picture below to aid us in explaining the simple maintenance procedures. The main photo above is a pull-out of the below showcase’s condensing unit. It has the compressor, condenser, and fan. It exists on the lower part of the refrigerator.

Clean your refrigerator fan-cooled condenser
Showcase refrigerator with a fan-cooled condenser

To work on the condensing unit, you don’t need to remove the whole assembly as it’s done in the main photo of this post. But remove the front and rear covers only, to allow you enough working space.

The tools you need for this task are common tools found in your  home toolbox:

1. Remove front cover

To begin, switch off electricity supply to the refrigerator and remove the plug from the wall socket. This ensures you work on a safe electric appliance.

A rectangular ventilation plastic or metal sheet covers condensing unit assembly from the lower front. Arrows 1 to 4 shows the position of the screws holding the plate in place. Some refrigerator models have only two screws.

Unscrew the four screws using your screwdriver – in most cases, the screws are cross notched. You’d need a Phillips screwdriver to unscrew.

In some models, cables connecting the pilot lamp and Liquid Crystal Display (arrow 6) are attached to the cover. You’re not able to detach the cover from the refrigerator body. But you can move it to the refrigerator side to allow you ample working space.

If it’s a refrigerator that has run for three to six months without cleaning the condenser, it has a layer of dust accumulated on the tube and fins. A refrigerator condenser in a dusty environment would have more dust on it though.

2. Remove rear cover.

The rear cover is a rectangular grill vent. It’s also fastened with screws on its four corners. Unlike the front cover screws which are concealed in some models, you can easily see the rear cover screws. After removing the rear cover, you get the best view of compressor and fan.

How to clean Your refrigerator fan-cooled condenser

3. Clean condenser.

From the front side of the refrigerator, use your brush to clean condenser fins and tube. The fins are originally shiny and clean. But accumulated dust makes them take the color of dust. As you clean the condenser with the brush, the dust and dirt settle on the iron sheet that’s carrying the condensing unit components.

On dirtier condensing units, you’ll find pieces of paper and light waste that the fan pulled in.

Clean your refrigerator fan-cooled condenser and the fan from the rear side because you can access them easily thus.

The drain pan could also be full of accumulated dirt. If it has screws holding it in place, unscrew and remove the container. Most of them are made of plastic. Wash it in soapy water.

4. Blow dust.

To blow dust using an electric hand blower is messy. First, suck dust using the vacuum cleaner to minimize dust that would billow into the open air while using a blower. After, use the blower to remove dirt and dust hidden between joints. Hold blower nozzle near the condenser surface and, while hovering, flush with the highest hand blower pressure. Do this from both sides you removed the vents.

After blowing dust, you may use a damp cloth to wipe off the remnant dust on the condenser and its surrounding. But if you have the technical know-how, give the condenser a water-pressure wash. However, don’t do it if you have no technical skills. You can accidentally flush water where it isn’t needed.

Conclusion

While a showcase refrigerator condensing unit is accessible from the lower front and back of the refrigerator, some chest refrigerator condensing units are accessed from the sides. You can also apply this same procedure to clean your chest refrigerator fan-cooled condenser.

And that’s it.

Screw back the covers.

Arrow T points to the Thermostat position inside the refrigerator. Your model may have it at a different position. So after you’ve done the cleaning, adjust it to the maximum level to test whether efficiency has improved.

Arrows L1 and L2 point to screws holding the neon light plastic cover. If the light isn’t functioning and you’d like to find out what’s the matter, remove the cover. It’s not a complex process. In most cases, two screws hold the cover into place. If you remove the cover and the light source is the fault, changing it is as easy as changing your house light bulb or fluorescent tube.

Bottom Freezer Refrigerator

bottom freezer refrigerator
Bottom freezer refrigerator

A Bottom Freezer Refrigerator is a home or office cooling device. It has two compartments. An upper and lower compartment. Its upper compartment is a chiller and lower compartment is a freezer. Hence the name bottom freezer.

You keep stuff that needs deep freezing in the freezer compartment and those that need chilling in the cooler.

Although a bottom freezer refrigerator differs in design from its top freezer counterpart, that doesn’t make any difference in cooling efficiency. It only presents a unique taste of style. For example, if the refrigerator’s height is higher, short people or children easily access items in the lower freezer compartment.

Suppose, in a given day, the family’s rate of removing and replenishing stuff from the lower compartment is high. The family members who have to stand on their toes to access the freezer of a top freezer refrigerator, find bottom freezer design convenient.

A basic bottom freezer refrigerator doesn’t have high-end features like the ice cube and water dispenser. With its simplicity, a basic bottom freezer refrigerator requires minimal space in the kitchen or dining area. However, make sure you maintain the recommended distance of two to five inches between the refrigerator condenser and the wall, for ample air circulation. A refrigerator condenser dissipates heat and needs space for the ambient air to neutralize the heat.

Like other basic top freezer refrigerator models, a bottom freezer refrigerator has one compressor. The compressor is the electric motor that pumps the refrigerant around in the refrigerator system in a process called refrigeration cycle. It’s a process that results in heat dissipation at the condenser. The air around the condenser should absorb this heat, and thus the reason you should leave some space between the refrigerator condenser and the wall.

Inner workings of a top freezer refrigerator

Inside the bottom freezer refrigerator chiller compartment, is a small light bulb for illumination.

A defrost heater runs along the door frame, to melt frost that sometimes freezes on the door and block it.

A thermostat is installed inside the upper cooler compartment, and it is marked with minimum to maximum settings. The thermostat switches the compressor off-and-on as the refrigerator temperature dictates.

A user should know whether this intermittent off-on switching exists because it helps in power economy. If it doesn’t, the compressor would run continuously without a stop. This means unnecessary power consumption.

An analog refrigerator thermostat is an affordable field replaceable unit. If yours develop a problem, and you are a lover of DIY, you can buy a new one and replace.

General information

When shopping for a basic bottom freezer refrigerator, the numerous number of models to choose from can overwhelm you. But the bottom line is, focus on time-tested brands.

Quality refrigerator manufacturers install quality compressors and other gadgets on their refrigerators. One sure way of verifying that the refrigerator brand is worth your money is to look at the compressor.

You can also consult a qualified technician or a user who has a good experience with a bottom freezer refrigerator.

Tip: Instead of running a defrost element along the refrigerator door frame, some manufacturers run the condenser tubing. The condensed refrigerant that flows inside the tube is warm, and it melts frost that would trap the refrigerator door. However, there is a disadvantage of a refrigerator built with condenser tubing run along the door frame if the tube is made of iron. Water condensate penetrates the joints to get in contact with the iron tube and cause oxidation.

Eventually, the iron develops pores through which refrigerant leak. If that happens, it would soon be the beginning of a user’s nightmare. She would need to weigh the cost of repairing the refrigerator and buying a new one.

Although every machine has a lifespan, a user should get value for money. Some refrigerators begin to give users a headache so soon.

Refrigerant Gas And Its Use

Refrigerant gas
30 lb portable refrigerant cylinder

Refrigerant gas is the substance that transfers heat in a refrigeration system. It does that as it flows in the system in a process called refrigeration cycle.
The refrigeration system is a closed tube system comprising the compressor pump, condenser and evaporator tube.
 
At the evaporator, the refrigerant absorbs heat that’s around the evaporator tube for it to boil. The refrigerant then rejects the heat at the condenser tube. So it’s a continuous transfer of heat from the evaporator to the condenser. However, the process is a reverse in a heat pump.
The evaporator is inside the conditioned room (for a mini split system). But the condenser is outside the conditioned room.
 
The refrigeration industry attribute invention and development of refrigeration systems to different pioneers. But one remarkable recorded invention is the Carrier air conditioner brand. Willis Haviland Carrier invented Carrier AC in 1902.
 
Since the invention of the refrigeration system, the refrigeration industry has used organic and inorganic refrigerants. R12 and R22 were once famous CFC and HCFC refrigerants. We used CFC R12 refrigerant in refrigerators and car air conditioners. But the industry terminated the use of R12. R22 which we charge into house air conditioners is on phasedown. The reason for R12 and R22 phaseout is that both have high Ozone depleting potential.
 
Countries have different phaseout implementation timeline. In the US, R22 phaseout will be complete in 2020 and in Australia, 2029. Other developing countries could take longer.
 
When industry players marked CFC and HCFC refrigerants for eradication, R134a replaced R12. R404a, R410a, and R407c are alternatives for R22.
 

HFC Refrigerant Gas phaseout

But again, the refrigeration industry is in another shakeup. Research reveals that R134a and current R22 alternatives have High Global Warming Potential. The industry is again phasing out HFCs. We see organic refrigerants and other environment-friendly refrigerants as the replacement. 
 
Stakeholders justify the regular changes in refrigerant gas because production and consumption are in millions of metric tons. If there is no check on environmental impact GWP, refrigerants can cause havoc.

 

Top-freezer Refrigerator Appliance

Top-Freezer Refrigerator
Top freezer refrigerator appliance

Top-Freezer refrigerator is a two-temperature fridge. Its freezer compartment is on its upper side and chiller on the lower compartment. The freezer compartment is smaller if you compare it with the chiller compartment.

A basic top-freezer refrigerator has fewer electrical and mechanical components.
Compressor motor of the fridge is the main component that consumes significant electricity. It is the pot-shaped component at the lower back of your refrigerator. It produces a humming sound when you plug your refrigerator into electricity. And if your refrigerator model has no lid that covers the space that houses the compressor, you can see it.

Direct cool or frost-free top freezer fridge

A top freezer refrigerator is a direct cool or a frost-free system.

Direct cool is the traditional technology for constructing a refrigerator system. Evaporator tube runs behind the inner refrigerator surface.
Ice build up in the freezer compartment when it has run for days.
Sometimes you may have to switch off your fridge and leave the freezer door open to defrost it. Stuff get stuck in ice and become hard to remove until you defrost the freezer.
Frost-free technology is the alternative for direct cool technology.

Frost-free technology introduces extra gadgets to the conventional system. Gadgets like evaporator fan, thermal switch, defrost heater and timer switch. All the gadgets, apart from the timer, connect to the evaporator. They work in harmony to defrost the refrigerator evaporator automatically. That’s why items you keep in the non-frost refrigerator freezer don’t get covered with ice.

Two compressor system

Some manufacturers install two compressors on a top-freezer refrigerator. Each compressor connects to one compartment.
Suppose one compressor dies. One compartment will fail. The second compressor and compartment will continue to operate.

A two-compressor system means that two compressors on your refrigerator consume electricity. You pay more in electricity bill. So, avoid this system if electricity cost is a concern to you.

Top-freezer refrigerator structure and size

Manufacturers produce different sizes of top-freezer refrigerators. A standard size freezer compartment in a two-temperature fridge is 1/3rd of the whole refrigerator storage space. A seven cubic feet refrigerator would store enough foodstuff for a nuclear family.

You can rearrange trays in the chiller compartment to accommodate drink bottles and pizza plates.
Top-freezer refrigerators ship with plastic containers for keeping fresh vegetables and fruits.

Some top freezer refrigerators have external condensers while others have internal. A condenser is the heat exchanger where warm refrigerant dumps heat in the refrigeration cycle.

An external condenser is on the back of your refrigerator or underneath. And if you touch it while your refrigerator is running, it feels warm. An internal condenser tube runs behind the refrigerator outer surface. If you touch your refrigerator’s outer surfaces while it is running, it feels warm.
Allow three inches between the refrigerator’s warm surfaces and the wall next to the spot you place it.  This prevents overheating.

If your refrigerator has an external condenser, always keep it clean and free from dust. Space between the condenser and the wall should be enough to allow enough air circulation to cool it.

Your refrigerator compressor also gets warm when the fridge is operating. This is another reason to place your refrigerator in a place with good ventilation.

The thermostat in your fridge cuts and connects electricity to the compressor. It does this intermittently when the refrigerator has attained set optimum temperature. This enables the fridge to maintain its set temperature and economize electricity.