fridge question

Eric,
On the surface, they sound a bargain. But...
The efficiency of the bar fridges is way below that of purpose-built 12v compressor fridges. Check the spec plate on the back of the fridge for power consumption, and you'll see what I mean - you'll find that it translates to about 10-15A from your 12v system when using an inverter.
The insulation is also thinner - the bar fridges are the worst for efficiency of the domestic fridges (compare the efficiency sticker on the front with that of bigger fridges).
The start-up current for 240v compressors is also higher than that for 12v compressor fridges, meaning you need a bigger inverter to turn it over.
And the bar fridges cannot take the vibration that portable fridges are designed to take.
Having said that, one or more Aust co's do use a 240v compressor with an inverter in a portable fridge, but I understand that they also use heaps of power.
If you really want an upright fridge,
- Engel make an upright (bar) fridge, but it uses the Engel swing motor; ie is reasonably efficient.
- 12v Shop (Perth) also carries a range of upright fridges using the Danfoss 12v compressor.
Gerry

Eric
I've thought about that as well, but the figures don't really stack up.
An inverter is usually fairly inefficient (they can get quite warm as they are losing power to heat) thus the power draw can be quite high so battery charge life is limited.
You can get a 12 volt fridge (Waeco, Evakool etc) about 50 ltr for $900 - $1000 (check the archives) which is not that much more than $800 for the other system.
As already stated uprights lose their cold air as soon as you open them up and then you have to go through another cooling cycle and use more battery.
If you are intending 4WD touring I doubt that a cheap upright domestic unit will last very long.
For camping only, the Chescold 3-way type is very good and cheaper.
I understand where you are coming from in this and I agree that there are heaps of other alternatives to achieve similar results in many areas of off-roading and camping etc without spending heaps of "hard earned".
I would, however, have serious doubts about the economy of the fridge idea.
Having said that, you can always "suck it and see", it might be the go for you.
It will be interesting to see responses from others who have had success with that system.
Cheers
OskarThe real oskar

Eric

I would be surprised if you could buy a decent inverter for those prices. They would be square wave or modified wave inverters and produce dirty power which can cause all kinds of problems to your electrical equipment.

There is a reason why car fridges cost as much as they do, and thats because most of them are designed for an enviroment where they will be knocked about.

The other point to make is that all fridge compressors aren't true DC units. Induction motors need an AC current to make them rotate, so regardless of what people are told there are no DC compressors out there yet.

We could talk about you wanting to use a domestic fridge for your application,but I'm sure your not driving a sedan or similar when you go off road so your logic is almost right.

Eric,
A standard 1500 watt inverter is not adequate for a 240 compressor or any thing else that has a top or bottom dead centre! Ask the experts like Jaycar before buying!!!

Wow! am I cute
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Richard