Originally Posted by edbulmer
I debating whether to buy an inverter for my regular size fridge or buy a small dc cooler. Which would be more cost efficient? I saw an inverter at WM for a hundred bucks that would produce 100 watts, would that be enough for a fridge?
This is a fairly huge subject. Efficient refrigeration
depends on good insulation
more than anything else. Most pre-built fridges have poor insulation
, because they want to advertise bigger interior
capacity. They don't usually shout about energy consumption
. When we pulled the built-in fridge off Ocelot, it had barely 1" of insulation. Our new one has 4" all around, 5" on the side facing the entryway (where the sun can come in) & 8" on the bottom.
12v refrigeration systems are usually a bit more efficient than AC units, because they know you're running off a battery
& not just plugging into the wall. Ours draws 4-5 amps (at 12v) when it's on, but it isn't on very much. We spend ~60Ah/day of our electricity budget
on our refrigeration.
But I suspect you're also talking about ease-of-implementation efficiency, and it's hard to beat plugging an AC fridge into an inverter. But it'll probably use gobs of power. You'll have to look at the power consumption
specs for your fridge to choose an inverter, but probably better to get one that's 2-3 times more powerful than you need. This will not only let it handle the surge-loads of starting the fridge, but will also let you use some power-tools or a blender as well.
But most cheap
inverters are only (slightly modified) square waves, & as mentioned above, some fridges don't like them. True sine-wave inverters mimic more exactly what comes out of a domestic wall socket, but they're more expensive to buy & less efficient to run.