refrigerator

[Lynn Coleman]

HI all,

We've been exploring various types of refrigerators to put into our TTT. We really like the size of the 2.7 electric that is offered at Walmart for $114. However, we're also looking at models that we can't afford right now but hope to be able to purchase next year. These are your typical refrigerators for RV's. They have AC/DC and AC/DC/Gas.

My question is how long would it run on battery if it uses 1.6amps on DC? In other words, how many batteries would we need for a solar system that pulls that kind of amps?

Another question based on our ignorance of understanding electricity is that the AC pull was only .6amps on the same unit that pulled 1.6amps on DC why the difference? We're assuming there is an energy loss in the conversion, is that a correct assumption?

Thanks for your input.

Lynn & Paul

[madjack]

Lynn...a few thoughts on refrigeration.......1) let me start by saying DO NOT buy a thermoelectric fridge(12v)...they will only cool to 40*s below ambient temp max and will drain a battery in about 12 hours.....2)Power(wattage) is power regardless of if it is a 12vdc unit or a 120vac unit so there is a 10 fold increase in AMPERAGE to make up the difference when going from 120vac to 12vdc...example...a unit pulling 2a on 120vac wll pull 20a on 12vdc...both are drawing 240wats....3) if you use a 120vac unit and rely on an inverter to go from 12vdc to 120vac, there is a slight power loss at the inverter...you will also need to becareful of wire sizing from the battery to the inverter since there will be a large amp draw between them.....4) there are 2 basic types of refrigerators that RV's use...A) compressor...this is similar to your household unit but the compressor runs on either AC or DC...B) absorbtion...this is usually an ammonia based unit that uses a heat exchanger for cooling...it operates on a heat source, that is either a 12vdc heater, a 120vac heater or a flame from burning a gas such as propane...


To give you specific information on power usage/consumption, you will need to give us model/make of units you are thinking of using.....
madjack

[Lynn Coleman]

To give you specific information on power usage/consumption, you will need to give us model/make of units you are thinking of using.....
madjack

Hi Madjack,

Thanks for the input. I don't have the information handy right now and probably won't for a few days. We've had a death in our community that is requiring a lot of our free time.

I'll get back with the specs in a few days.

Lynn

[Lynn Coleman]

To give you specific information on power usage/consumption, you will need to give us model/make of units you are thinking of using.....
madjack

Here is one of the units we looked at:
http://www.lowes.com/lowes/lkn?action=p ... lpage=none

The other one that showed real promise was:
http://www.lowes.com/lowes/lkn?action=p ... lpage=none

The second is a more economical unit, the first has greater freezer area. The real question to ask ourselves is what we are going to need it for.

Most locations we'll be able to hook up with ac. However, we hope to put in a good solar system next year and I'm wondering if these units made simply for ac are worth while. On the other hand they might be for this first year and we can simply sell them when we're done with them and put in a better system. So my basic question for the two above units is if I were to have the solar system in place would these units be worth my while with the appropriate invertor/convertor? And if so, how many batteries do you think we should have to run the above units?

As for units that are both ac/dc and gas we were looking in an RV catologue. Prices ranched from nearly six hundred to eight hundred for a small fridge. I'm leaning more towards strickly ac/dc and not having a propane tank. On the other hand, propane is good for a variety of things. Can one travel with their refrigerator hooked up to the propane tank? Isn't that dangerous on the road. So, running a frid while traveling we'd definitely would need the dc connection, right? Am I understanding this correctly?

I'll have more question but I don't want to over tax anyone at the moment.

Lynn

[Keith B]

Lynn... Can you mount a propane bottle on your tongue.. maybe even two... plumb to your galley for stoves, lanters, fridge, cabin heat, etc... Also..if you're worried about cost, call Colaw RV salvage... I've had EXCELLENT luck with them... they might have a salvaged 2 way fridge that you could afford, like out of a newer pop up or something...20#s of propane will last a LONG time; and being a 2way fridge, you could "precool" it at home with the camper plugged in a couple nights before... just a thought. Colaw: 417-548-2125

And also.. yes, the fridge can be hooked up to propane on the road... all motorhomes and camper fridges are on 24/7...switching from 110/gas automatically... I have a 3 way in my motorhome...but NEVER run it off battery...not when propane is so much more effecient for cooling.

Also...while most people believe that propane and natural gas are dangerous, they're actually quite safe...but still, you have to use common sense... It takes the perfect mixture of gas/air for an explosion to occur... Go light your bar-b-q grill... you'll see the flame just follow the burner... now close the lid and turn the gas on then light... BOOM... I can't remember what the EXACT calculation is...but it's 10-19% of gas to saturate air for an explosion... you USUALLY smell it before then...that's why they add chemicals to the stuff, so you CAN smell it... If it were me.. I'd run the plumbing exterior - any "leaks" you were afraid of will be displaced into the air and NOT into your cabin/galley..and a good set of regulators, gages and shut off valves are cheap protection as well... bar-b-q dials are not a good source of "valves"... you could plumb propane with EVERYTHING and be VERY safe for well under $100 (not including the propane bottle/gas).

[clkelley564]

Many of the big RVs run fridges on propane on the road. The only place you are REQUIRED to turn off the gas is in tunnels. The tunnels that require this usually have a parking lot and inspection station right before for just that purpose.

[BobR]

I have been very satisfied with my Dometic 3-way. I think you can still get these at Camping World