Fridges

[Toshbins]

Still out looking for our first camper. Getting lots of ideas from everyone we visit and we've made quite a few decisions on what not to buy, and quite a few where the jury's still out. What about fridges? 3-way fridges seem to be the norm, and unless you have a tiny gas locker, gas consumption seems OK. But what of compressor fridges? Some say that they are better than the 3-way - especially when running 12 volt. And for sure less complex. But what about electric consumption - Tischer won't fit one without double batteries and double solar panels.

[rubberrat]

It depends on your style of camping.
Wildcamping off hookup then you will be happier with the gas option. Camping fridges work best on gas.
12v tends to hold temp ok but isnt great at reducing temp so avoid opening door etc.
Mains is always fine.
We are often away for two to three months so try a number of gas saving tricks so 2 x 6kg calor last. Coleman petrol stoves for outdoor cooking for instance.

Solar panel gives you a good chance of the leisure batteries holding out if off grid.

A mix of power sources works best in our experience.

(Dometic absorption fridge)

[Gary W]

Pros and Cons on paper….

Absorption

• Pros:
  
  • Cheap to buy
    Cheap to install as independence from 12 volt system reduces demands on electrical, charging and battery installation
    Dual fuel - option to use gas or 220v
    No moving parts
    Quiet (silent) operation
    Good option off-grid if gas is more reliable fuel source than solar or wind.

• Cons:
  
  • Relatively inefficient.
    Unable to maintain standard 4° refrigerated at higher ambient temperatures. Example: at 30°c ambient 10° refrigerated at best is typical.
    Must be perfectly level for gas operation or efficiency and appliance lifespan is drastically reduced
    No effective 12volt operation so not suitable for keeping food frozen or chilling foods whilst travelling

Compressor:

• Pros:
  
  • Cooling effective even at very high ambient temperatures. Example: at 40°c ambient 4° refrigerated and -12° frozen is still possible.
    Operation unaffected by movement or angle
    Can freeze and chill food on the move
    Many modern units suitable for solar operation.

• Cons:
  
  • More expensive to buy
    Significantly more expensive to install as needs high grade electrical, charging and battery installation to be practical
    Quiet, but not silent operation

And in practice...

For travelling and touring compressor fridges win every time, not least because they are always working. For off-grid style living the absorption has some advantages. If the fridge is to be treated as a glorified cool box to stop milk curdling it’s a cheap and satisfactory solution. Also where solar or external power is unavailable, especially in lower temperatures and where snow may render solar panels useless for example it’s often the easiest and cheapest solution. If however if you want to use it on the go and it is to be used as you would use your fridge/freezer at home, the compressor fridge is the only option.

The problem is you can’t just replace an absorption fridge with a compressor fridge and do nothing else. The camper's electrical installation must be designed with it in mind. A single 120a/h 'deep cycle’ battery at the heart of a well engineered system will run a compressor fridge happily in the middle of summer for a long weekend with no external input. If you have a good quality solar panel of 80 to 100 watts, the panel will easily keep up with the fridge.

The whole system must be right though. A ‘leisure' battery is not a 'deep cycle' battery, it’s a marketing ploy. To get power from a battery you need lead and lots of it, but lead is expensive. Inventing new and misleading definitions is cheaper. A ‘leisure battery’ is fine for the water pump and a few lights, but not for a fridge, so ideally you should start with a decent deep cycle battery. Then you need to charge it. The standard method of charging a caravan/demountable battery on the move is through a split charge or VSR relay via the trailer socket. Due to voltage drop, the physics of batteries and the way alternators work, it is unlikely that the ‘caravan’ battery will ever be fully recharged via this method. With Euro 5/6 engines it’s not just unlikely, it’s all but impossible as these engines need their batteries to have 20% ‘headroom’ free for their regenerative system to function. In other words they are only normally charged to 80% so to get a full charge a 'battery-to-battery' charging system is needed. You also need the shortest possible wiring run and substantial wiring with decent heavy duty connectors to minimise voltage drop. The list goes on, but you get the picture, it’s expensive to do it correctly. In reality all this doubles or maybe even trebles the cost of the fridge installation. At the end of the day most buyers of campers, motorhomes and demountables just assume that a fridge is a fridge is a fridge and wouldn’t pay the extra no matter how much time you spend explaining pros and cons so a lot of the time that extra cost can be difficult to justify. In our little niche in the market most customers know exactly what they want and most choose compressor anyway so for us it's easier to make it standard. Horses for courses...

Sorry it’s so long winded, but hope it helps anyway

Best wishes

Gary