Thread: Inverter versus 12v

F

Yes.
You are adding the power losses of the inverter which, at times, can be quite high.

Oh, Rod, this isn't facebook.

Thanks Mick. I wasnt sure how id keep tabs on this one coz its a subject id like to know more on. Cheers

Yes what does F mean?

As Mick said inverter losses can be substantial particularly with big inverters. Also 240v fridges dont have to worry about minimising power usage for cooling capacity so generally a 240v fridge will use more power than a 12v fridge for the same cooling ability.

I recently looked at this for the 3 way in my camper. 12v fridges were either too small or too big to fit into the slot so I looked at using the correct size 240v bar fridge to fit the slot for use with an inverter. Overall 240v fridges used half again the power of similar sized 12v fridges so as well as the increased power usage from the inverter you need to take into account the power use of the 240v fridge.

Garry

F means Following......its a fb thing. I got confused

Originally Posted by 67hardtop

Thanks Mick. I wasnt sure how id keep tabs on this one coz its a subject id like to know more on. Cheers

Just above the top post, there is a menu bar. The left most drop down, that is in about the middle, is "Thread Tools". Click on that and select "Subscribe to this Thread". You can then follow all your subscribed threads by listing your subscribed threads by selecting "Subscribed Threads" under "Quick Links" in the top toolbar.

You can even set up to be notified if there is a post in that thread.

Thanks Mick. Im using aulro on my phone. Ive found a tick symbol in a white round circle. It says subscribe to this topic...lol...or unsubscribe if u select it again...hehehe...

To go back to the original question....

The answer is ... it all depends. The power used through an inverter will be the power used by the refrigerator multiplied by 100/E, where E is the percentage efficiency of the inverter at the output current needed to run the refrigerator. This efficiency typically varies widely according to the output, but is often quoted for an inverter as a single figure, mostly (you guessed it) the highest efficiency, which is usually close to maximum output. So high power inverters, running at low output are typically inefficient, perhaps as low as 70% or less, where their best figure is over 90%.

But this is not the whole story. There are a limited range of 12v refrigerators, but a far wider range of 240v ones, although if you need a small physical size, 240v ones tend to be less efficient, and "bar" fridges, for some reason tend to be very inefficient. While the fact that they run off batteries tends to encourage manufacturers of 12v units to make their devices efficient, mandatory labelling and energy efficiency laws tend to do the same for 240v manufacturers.