When we got our motorhome, I never thought much about leveling my RV for the fridge to function. I soon learned otherwise.
So does your RV Fridge need to be level for it to work? According to several manufacturers, an RV fridge does need to be level to within three degrees off of level to function within the intended efficiency of an absorption refrigeration unit. A Refrigerator that is off level greater than three degrees will not cool as intended as the chemical process in the refrigeration unit will not function to maximum efficiency.
An Absorption Refrigeration unit does not use a compressor like your home fridge that compresses refrigerant to remove the heat from the fridge cavity. Though they do operate in very similar ways. An Absorption Fridge uses heat in combination with a chemical process to remove heat from the food compartment in your RV’s Fridge. There are no moving parts in your RV Fridge, just a series of metal hoses that contain water, ammonia or sodium chromate or both. An Absorption Fridge is more efficient and rugged and thus suited for RV’s.
The Rest of this article will focus on how the chemical Process works in an Absorption Fridge, and some more common questions people ask. Such as how long it takes to cool a fridge and when can I put food in. How can my Fridge operate on three different fuels? What are these fins at the back of my Fridge? Why is there ice build up on the fins in my Fridge? And how much does it cost to replace my fridge?
How an Absorption Fridge Work?
Here is a summary of the basic principle of how an Absorption Fridge functions. There are three steps:
- Evaporation phase: The refrigerant (ammonia, water, and sodium chromate) is heated and the ammonia is separated from the water and sodium chromate solution. The ammonia Rises in the tube and travels through the coils.
- Absorption phase: The ammonia gases cools and falls through the condensation coils, in your Fridge, the part where your fins are in the back of your fridge. As the ammonia falls in the tube it recombines with the water and sodium chromate solution on the outside of the fridge. Thus the coils are hot on the outside as the heat is transferred from the inside of the food compartment to the outside of the fridge.
- Reheating phase: As the liquid recombines and falls, it is then reheated again and step one is repeated again when heat is applied to the liquid.
Here is a good video that goes into details on how an absorption fridge works.
How long does it take to cool your Fridge and when can I put food in?
Normally it takes 8 to 12 hrs to cool your RV Fridge to a temperature range 29 to 36 degrees by using AC or Propane. Your Freezer should be at about 0 degrees. You can then load your food in from your home fridge or grocery store. It is best to load food into your RV fridge that is already cool and so does not put much of a load on it as you a filling it up. Remember not to pack your fridge too full as that will block the airflow inside the food compartment and create a uniform coldness in your Fridge.
How does the fridge operate on three different fuels?
How an RV fridge operates on three different sources of power is accomplished by utilizing heat and a chemical process. Unlike your home fridge that uses only a compressor and one power, AC. The heat for the fridge is generated in three different ways; with propane, it uses a hot plate and a flame, (technically 12 volts is required to ignite it) AC or plug-in power a heating element and a 12v heating element warms the refrigerant. The 12v operating mode is not as efficient and less desirable for long-term cooling.
Why are there fins in the back of my fridge?
The Fins, usually made of aluminum, which is a great conductor of heat, help to absorb the heat within the food compartment in the Fridge. Thus cooling the fridge to the desired temperature. It is important to think about how you will arrange the food in the fridge as items closer to the fins will be cooled more than things away or near the bottom. We always keep things like pop, juices and water and meats near and produce like lettuce on the shelf farther from the fins.
Why is there build up of ice on my cooling fins in my fridge?
A build of ice on the fins not only decreases the efficiency of the fridge, it also makes the cooling system work harder and reduces the overall temperature in the fridge. The build-up of ice on the fins has to do with too much moisture in the food compartment. To reduce moisture, it is best to keep things in sealed containers and plastic zip lock bags. So that the moisture of the fridge is kept to as low as possible as well as keeping the fridge closed for longer periods of time, especially if you are in a humid location. If you have ice build up, then defrosting the fridge is going to be required at some point.
How do I defrost my fridge?
Defrosting the fridge is best done by turning off the fridge, wedging the door open the door and allow the ice to melt. Emptying the fridge of its contents will prevent those foods from spoiling and the drippings can be caught with a container under it. If you are in a rush and you are plugged into shore power then you could assist the melting with a hairdryer. But I have found that it really only takes 2 to 6 hrs depending on the outside temperature. Do not use something sharp to chisel off the ice from the fins. Doing so could cause a puncture in the hoses and cause coolant to leak. Once all the ice has melted into water and can be cleaned up with a towel, you can now either turn on the fridge again or keep it wedged open for storage.
How much does cost to replace my RV Fridge?
A basic 4 to 6 cubic feet RV Fridge can cost anywhere from $600 to about $1600 dollars and that does not include installation. Depending on the size of what you require the price can go up from there to upwards of over $3000.00. The Installation cost can be another $1000 to $3000 if you choose to hire someone else to do the removal and install for you. If you are handy, then the cost will be just your labor and some additional materials will needed to complete the job.
So there you have it, the fridge really needs to be as level as possible for it to function at it’s intended operating function. I have also gone through explaining the process of how an absorption fridge functions. As well as some other maintenance items. If you are having problems with your fridge not working or you need to troubleshoot why your fridge is not working you can go to my article on that.