Power Consumption 12 V Cooler VS 12 Fridge

[Spaceman Spiff]

if you have a space heater of a 1000w, would it be better to run it on 12v or 120v?

there's detailed posts here for 3.7cu ft unit using ~50A a day. Mine is running steady with overcast on a 80w panel. there's youtube vids of measured usage that all seem to agree with the rest.  In fact the only thing I've seen against them so far are claims here of "I tried it once."

there's no free energy.

I did not get your space heater analogy either.

I have an old 2.1 cu.ft. Norcold 12/110 refrigerator.  I have never seen it take more than 28AH in a day (a 90+º day).  If you are getting 50AH out of an 80W panel in overcast conditions you are doing exceptionally well.

I've not seen anyone give a report on survivability of cube fridges after a year or two either.  Anyone?  I looked at small 110 refrigerators when I was doing my buildout because of the age of my current refrigerator (35 years) and the attractive cost of the dorm room sized fridges.  Both from an energy usage and survivability standpoint, I decided to stick with the dinosaur.

No free energy, but I do have MOBILE energy 

 

[jonsun]

oh IDK a 3 minute searched turned up dorm units going 3 years, 5 years, etc in a thread about a broken norcold

http://www.thehulltruth.com/marine-electronics-forum/264044-refrigerator-849-159-110v-vs-12v.html

I've yet to hear of one breaking down.....or using significantly more energy. Where are we all getting they break down exactly?

Think you need to re-read the post again. Mine isn't a 3.7cu ft. The 50A a day is from a detailed usage thread on here. Mine is a little 1.7cf with low 70's day temps pulling about 20A daily. (measured 4.6a with 10-15% duty cycle)

which lets put that in perspective 3.7cu ft (pretty sure that's what it was) is 110 quarts. Like nealry 2 of the biggest whynter's. those talking about using 20, 30, 40 amps are doing it with fractions the size.

 

[jonsun]

to the space heater it's a simple question what is more efficient running 1kw at 12v or 120v? no need to factory in ohms law or inverter inefficiency. Or do it, that's fine too.

 

[highdesertranger]

actually it's the same amount of power. doesn't matter the voltage, 1KW is 1KW. now when you start converting is when you start losing, as simple physics tells us no conversion is 100% you have loses. the fewer conversions the more efficient. although heating anything with electricity is very inefficient doesn't matter the voltage. highdesertranger