10 Ways to Reduce Energy Use of a Car Refrigerator
The car refrigerator is the ultimate in camping comfort. The menus can be expanded to include almost anything you can cook at home, as long as you can fit it in the fridge. Portable refrigerators these days are extremely popular additions to any camping and 4WD setup, and they're well and truly worth the expense if you go out regularly.
However, a refrigerator requires a lot of energy to operate - it is almost always the highest energy consumer and you have to get that power from somewhere. It's true that solar panels and batteries are great solutions, but there is a lot you can do to reduce the energy consumption of your car refrigerator.
How much power does a refrigerator need?
There are many different factors that affect the energy consumption of the car refrigerator. While the list goes on with questions like size, compressor style, ambient temperature, insulation thickness, temp set to cool, what you use it for, however, most will consume between 1 amp and 6 amp per hour (2.5 amp average) in operation. A refrigerator usually doesn't run 100% of the time, so it only draws this current when the compressor is turned on.
Most refrigerators are loud enough that you can hear them within a few meters. Again, the cycle time varies considerably, but on average they run their compressors about 50% of the time. We can assume that the refrigerator draws 2.5 amps with the compressor on, but only runs 1/2 of the day.
From which battery should a refrigerator regenerate energy?
The refrigerator should never run out of the starter battery you use to start your vehicle. The only exception is if you absolutely have to, it can be charged while driving. The reason behind this is simple - your starter battery is essential to starting your vehicle and if it discharges it can cost you time and frustrate you.
The most common way to start the refrigerator is to use a second battery isolated from the main starter battery. The best option is a deep cycle battery, which (as the name suggests) is designed to cycle from 1200 to 1700 times from full to half and back again. Lithium batteries are also becoming more popular as they have several advantages, but it is a fact that they come at a very high cost.
How long can I manage with the battery?
Too many people think that just because the refrigerator is running, there is enough power left in the battery. This is not the case – you should not run your battery below 50% of the charge, which is normally around 12.2 – 12.3 volts.
A refrigerator will continue to operate well below this until the low level alarm sounds and the power is cut off. Most refrigerators have a low-level interruption, but it usually doesn't drop much below 12 volts. If you run your battery below 50% charge, its lifespan will decrease rapidly and batteries are not cheap products.
If you have a 100 amp hour deep cycle battery, you should only use 50 Amps of its capacity (with no further consumption), which is only 1 and 2/3 (without further consumption) in the scenario above before damaging your battery.
After this point you should start your vehicle and let the alternator charge the battery or set some solar input. However, things seem a little hopeless when you have a few cloudy days. Using your vehicle's engine to charge the battery is also a very costly way to handle this charging job.
So, how can you reduce the energy consumption of your car refrigerator? It's essentially similar to keeping ice cold longer in an ice box.
1. Before leaving the house, pre-chill the food and drinks you will place in your refrigerator
Do not put room temperature products in your refrigerator. This causes it to work harder and use more power. Before putting the products in the refrigerator, make it a habit to pre-chill them. Of course, there will be moments on the road that are not possible while driving, but if possible, cool your food and drinks beforehand.
2. Gently open and close the cover
If you unlatch your refrigerator and pull the door up, this quick action draws a large amount of cold air from your refrigerator and sends it into the atmosphere. When you close the lid, the refrigerator needs to cool the hot air you fill.
The trick is simple – open the door slightly until it opens about 10 cm and then open it normally. This will stop most of the cold air from escaping and save you quite a bit of power consumption.
3. Keep the fridge full
A full refrigerator works much more efficiently than an empty one. Water bottles come in handy if you're running low on food and drink in the fridge. When they cool, you save some energy, as they don't change the temperature as quickly as the air does with the door open.
4. Keep your refrigerator as cool as possible
The difference between two refrigerators operating at an ambient temperature of 25 to 40 degrees is really huge. The warmer the air outside the refrigerator, the harder it will be for your compressor to start. Keep the ambient temperature completely Although you cannot control it, you can control where your refrigerator is stored.
For example, parking under a tree will keep your car much cooler and lessen the work the refrigerator has to do to keep your food and drinks cold.
5. Airflow is required
It's all well and good that your refrigerator is tightly packed, but if it can't breathe freely, you're overworking it. Make sure the compressor has enough room to suck in clean, cool air. If you have installed the refrigerator indoors, you may want to consider using a small vent or computer fan to aid air circulation.
Tool boxes on the front of camper trailers are popular for mounting refrigerators, but they can easily reach 65 degrees on a hot day. It cannot be said that it is very good for your car refrigerator in terms of its long life, and it is obvious that it will definitely cause more power consumption.
6. Refrigerator doors
You will find that many refrigerator manufacturers sell covers for their refrigerators. These help protect the refrigerator but also improve its insulating properties. The better insulated your refrigerator is, the less heat that goes in and the less cold air that can get out.
The next time you're at your refrigerator, touch the outside of the refrigerator while it's running. If it's noticeably cooler than the air around you, the insulation is letting the cold out.
7. The time and number of opening the door of your car refrigerator
The longer you leave your refrigerator open, the colder it must be when you turn it off again. Make it a habit to quickly grab what you need and close the lid.
Before you open the refrigerator, think about what you need. Reducing the number of times the refrigerator is opened means that it saves the energy it will spend on cooling the chamber again.
Keep a small ice box handy to avoid having to open the fridge too often and to keep your drink cold.
8. Close the cover properly
While it's easy to just close the door and not lock the latches, if any air gets in and out, this will cause the refrigerator to work harder. Take an extra 2 seconds to turn it off.
9. Check the wiring
Your refrigerator's power supply must have an adequately sized cable. If it's too small, you'll lose efficiency pretty fast. Usually this is an issue from your battery to the power point of the refrigerator, especially if it is running from the front to the rear of the vehicle. It is recommended to run a minimum of 6mm square cable.
Be mindful of your voltage usage.
10. Use a quality refrigerator
Finally, if you've just bought yourself a cheap refrigerator and think it has insufficient power and insulation, it may be time to replace it. There's nothing like being able to grab a cold drink from your fridge in the midst of poverty. Enjoy the luxury, do your best to conserve energy, and if your car fridge still consumes a lot of energy, consider the solar/battery option.