Off grid refrigeration

Discussion in 'Off Grid Living' started by Bluecore, Jun 10, 2013.


  1. Bluecore

    Bluecore Monkey

    Hello everyone!
    My husband and I are new to the "off-grid" experience. A little background:
    In September of 2011 we purchased a vacation house in the mountains of TN - our little piece of heaven. It was built to be run off a generator. It had only enough trees cleared to build the house and the mountain is heavily wooded thus solar isn't really a viable option. We have completed the majority of the work that needed to be done to a place that sat empty for over 4 years (it was a foreclosure), wasn't winterized, had all the copper lines cut out and generally needed lots of repairs.
    Anyway, we are rapidly reaching the point of making some long term decisions about how we need/want to power our home because we would like to eventually retire there or at least live the dream of dual residency with winters here in Florida and summers up there. We currently have a 15kW propane generator. Yes, this is huge. But the price was right - less than $1,000 for a generator that was only fired up during the monthly tests. We installed LED light fixtures in all the rooms and have tied them into a single 12v deep cycle battery. Works awesome. I cant tell you how exciting it is to have lights at night without the sound of a generator. I see a battery bank and inverter/charger in the very near future.

    Now to my question:
    Refrigeration. While researching whether to use propane or 12v DC Sunfrost (very expensive and probably not as efficient as they claim) - I decided to compare to the new energystar refrigerators and I was a little surprised to find how efficient the newer energystar appliances are. Does anyone know if the cost of the Sunfrost is worth the efficiency? I'm thinking that for over $1,000 savings; I could buy more batteries. Until we retire, the longest we will spend at the house is 2 weeks at a time. My needs are simple; but right now we are forced to come off the mountain every other day for ice for the marine coolers. We spent a small fortune on ice! This last trip (just got back on Saturday), I actually had 2 packages of meat spoil in the coolers.
    I searched for any other posts about this and could not find any. Any advice/insight would be greatly appreciated by my husband and I.
    I am sure that I will be needing more help over the next several trips and value all opinions.

    Thanks!
    ~Becky
     
  2. BTPost

    BTPost Old Fart Snow Monkey Moderator

    Becky, You might just look around for a Used Refer out of a wrecked RV.... These make very nice Cabin Refers and will run on Propane, 12 Vdc, or 120 Vac if you get one of the "ThreeWay" powered ones. We bought one for our Beach Cabin, New, from the Manufacture, when we built the place, and built it into the Wall of the Kitchen. Dometics was the Brand Name of ours, and it holds the Milk at just above freezing, just fine, as well as keeping the Frozen stuff, Hard, in the small Freezer compartment. These are "Ammonia over Hydrogen" type Systems, and that technology has been around since the 1930's. It was used in the Old Kerosene Refers, that were sold to the Hillbilly's of Appalachia back in the day. Defiantly will fit into you lifestyle, and they are pretty good on fuel, as well..... .....
     
    chelloveck likes this.
  3. Pyrrhus

    Pyrrhus Monkey++


    Lehman's - Dometic


    I know nothing about any of this except for what I have read on the interwebz. I do intend to get one of the Dometics after I move.
     
  4. I would stay far away from propane for refrigeration. Aside from the bills adding up in the long term (though solar might have more up-front costs), propane reliance sort of undermines the idea of trying to not be habitually dependent on others for a steady stream of energy source. I view it a lot like a rat in a cage pressing the feeder bar to release a pellet of food every so often, and so being habitually reliant on his handler.

    I don't know whether a Sun Danzer or Sun Frost would justify the initial cost outlay (as they are pricey) in your personal evaluation, as compared to a reasonably energy efficient 'budget' model, but compared to propane I can't see there being any real dispute that you shouldn't go with an electric model which can run off solar. I'd go electric, even if that meant having to get a cheaper brand for the time being (and the money savings could, for the time being, go towards upgrading your other infrastructure facilities like buying more batteries so you have more capacity).

    If energy efficiency combined with a limited budget were the primary concern, I'd stick with a chest freezer over an upright refrigerator. The fridge could be makeshift duplicated, for the time being, by just having a very large sized Coleman cooler (with added insulation) that you keep stocked with ice from the chest freezer (or separate ice maker which you can get for $80).
     
  5. Akheloce

    Akheloce Monkey++

    Another option is an icebox. I bought an ice maker a few years back, and when the generator is running, (few hours a day) I'm making ice. For now, I'm just using coolers in the mud room, but eventually will be an old style ice box. I can get several days out of a batch of ice.
     
  6. Bluecore

    Bluecore Monkey

    Thanks for all the replies!
    As to propane:
    When we bought the house; the company that was servicing it refused to come back up. In fact; they sold us the 500gal tank for $300 to keep from coming back up. The next company I found also refused to service is even though they service the next hunting cabin down (< 1/4 a mile away), the next company would come up; but only in the summer if it wasnt raining. That company was bought late last year by Suburban. And while they retained the employees; they closed the local storefront. Obviously, this has me concerned that we may not be able to get propane dependably long-term. Our best shot at maintaining a good relationship with the propane company is to continue to "re-surface" the mountain road leading up to our place. The first section cost over $2,500 to repair and we will certainly not get another propane truck up there without resurfacing another section. My point is: we are at the mercy of the propane company and whether it not they "want" to service our place. I reckon if we were there more or consuming more it would be more financially lucrative for them. But we are super-conservative with the propane. We run the generator a couple hours every other day or so. We have used less than half the propane in one 500 gal tank in over a year (4 trips avg out to 8 weeks) and less than 20% in the other 500 gal tank (heaters, water heater and oven). So, $2,500 in road repair plus about $1500 to fill the tanks a year = a pretty nice battery bank and inverter/charger.
    While we were there for the last two weeks, we needed to repair some of the wood siding after I pressure washed and before I stained. While on the roof we noticed two things; we need a new roof pretty soon and the side of the house gets about 4 hours of direct sunlight (during this time of year). This said side of the house faces west southwest. So, while we can't clear trees to install solar panels - this area of the roof may very well be a viable option for a PV system.
    So, seems to me that 12v DC is the way to go. I dont like losing in a conversion from 110 to 12v but would be willing to. We would love to be truly self sufficient up there if possible. While it wasnt our original intention when we bought it - the stark truth is that it would be the place to be/go if things go horribly wrong here and we have been stocking it accordingly.
     
  7. DKR

    DKR Interesting ideas, interesting stories

    If the local meth heads stripped out he copper, have you had trouble since you bought the place?
    We gave up on ours (out of state in a rural area) as everyone in the area decided that since we didn't live there full time, it must be abandoned - and it was OK to steal whatever they wanted. I would love to have a hideaway, and would also love to have neighbors who didn't steal everything not nailed down, and sometimes stuff that was nailed down.....
     
  8. Bluecore

    Bluecore Monkey

    You are right about the local meth heads!
    No, we haven't had anything stolen. Neighbors at the base of the mountain have taken steps to lockout vehicle travel. Four wheelers can access from other directions; but we haven't had trouble with that since our second night there; when someone came up the "road" in the middle of the night to be greeted by my husband chasing them with a rifle. Since the closest town has less than 2,000 people - word got around pretty quick that we were there and armed. That being said; we are careful not to leave anything outside that we will miss. Except the generator. A 15kw generator isn't really portable. We have done everything we can to make it REALLY difficult to take. But the truth is: if someone sets their sights on something then it is likely that they will get it. Even in a big city.
    We had a lot if the same concerns as you. We make every effort to get up there as much as possible and we aren't always visible while there (if we don't run into anyone at the local 24hour ice machine).
    We love the place. It was a risk to buy the place and we are at the age where we still have a good 20 years of working left so we are trusting our neighbors and the chain across the access point to our property. We would be heartbroken if we were robbed; but it wouldn't chase us away. An encouraging fact was that the place was left UNLOCKED for 4 years. True, nothing of value was left outside. But the inside was perfect. No vandalism, all the appliances were still there (except the propane fridge taken by previous owner) and it was clean. Hunters had clearly been staying there and using the toilets (which didnt flush). Other than that, it was perfect inside.
     
  9. BTPost

    BTPost Old Fart Snow Monkey Moderator

    Inverters are another topic, that you will need to research.... Might I suggest that you look at your Electrical Needs and make a list of the Required Power for each one. The "Rule of Thumb" for Inverters is 0-1Kw 12 Vdc, 1-3Kw 24 Vdc, and 4Kw-Up 48 Vdc Battery Bank Voltage. The real Question, you should be looking at is "How are you going to charge the Battery Bank?" You have said Solar is not a good Option in your location, so that just leaves Wind, and MicroHydro as Renewable Energy sources.... The 15 Kw Propane Genset is a bit BIG for a small Cabin. You would be better off, with something on the order of 3-5 Kw in a Genset, for such a single dwelling Outfit. You can look on Craigslist, and see if you can find a nice Onan Genset, pulled from a wrecked RV, in that range. Then do the simple Propane conversion, to make it a Dual Fuel unit. (Gasoline/Propane) Use Propane for your Primary Fuel, and Gasoline as an Emergency Backup fuel. This setup would save you considerable on Fuel Consumption, as you aren't turning all those BIG Moving Parts, when you only need 3-5 Kw to keep you Batteries charged. Keep the Big Genset for a Backup, or Sell it off, to finance a unit, more appropriate to you operations. These are all practical suggestions that come from living out in the bush of Alaska, for the last couple of DECADES. I generate ALL my own Power, and have Inverters/Battery Banks, that run my outfits. @TnAndy is also an OffGrid'er that has years of experience, in operating a Household, with no Grid Power.
     
  10. DKR

    DKR Interesting ideas, interesting stories


    Lucky you.

    For the fridge, consider a NorCold. Now owned by Thetford, they make a line of both RV and domestic appliances than are AC/DC and gas. We have a Norcold in our older 5th wheel, fridge with separate freezer. AC/DC/gas - might be worth looking at to run on gas for the time you are in residence and then switch to AC when you get a working system installed for you full time residence.

    Best of luck.
     
    BTPost likes this.
  11. natshare

    natshare Monkey+

    This doesn't really answer your refrigeration question, but if you're chaining anything up outside (like, perhaps, a semi-portable generator), look into getting a hardened steel chain, with at least 5/16" links. Used with a high security (difficult to cut) lock, and locked to a sturdy tree, and they'll either have to cut down the tree, or have an oxy-acetylene torch to cut the chain or lock!

    I discovered this the hard way, when working at a power plant, and they ordered hardened chain for our tilting truck dumps. You can lean on a bolt cutter handle all day long, and it will only put a dimple on that steel!! Torch cutting was the only way to cut it to length.....but then, we were using these to hold 18-wheeler trucks in place (safety chains), while they were being tilted up to ~70 degrees from horizontal, to dump the wood fuel they were carrying in for us. :eek:
     
    BushcrafterAnthony likes this.
  12. billwilson

    billwilson Monkey

    Truck fridge :)
    I have one in my BOV
    Has been running non stop for 3 years

    4.2 cubic foot
    They have larger ones
    12v and 110v

    I have 360 watt hours of solar panels
    400 amp hours of storage

    I can go 3 days with no sun
    Lights
    DVD/tv
    Microwave for food
    Laptop and cell charging

    4 hours of sun a day top off
    My batteries

    Per blue sky tech (they make the controller for the solar)

    My set up could easy power a cabin
    The only Xtra draw would be the LED
    lights which don't amount to much

    I would look at solar and wind to
    Top off a battery bank

    Pm me if u want tech details

    BW
     
  13. VHestin

    VHestin Farm Chick

    A root cellar if possible would be a good choice, especially since you could disguise the entrance. I'm having the hole dug for me next month by a neighbor. I could do it myself if I had nothing else to do, but I am going to be happier just hiring their backhoe for about an hour.
     
  14. -06

    -06 Monkey+++

    Have accumulated a few R/V fridge units in preparation for the cabin--moving it to an off grid location this year. You may consider taking out a tree to give you more sun exposure for PV usage. A local bud has been off grid for 15 yrs. They just added two more panels to boost their AC demands--getting soft in their old age--lol. Put that tank onto a small trailer and tow it for filling. Get a 100# tank for a back up. Our first propane kitchen range used a 100# tank every 8 months. Should last you much more as we were cooking for four children on it.
     
    Thmstr likes this.
  15. WindWarrior

    WindWarrior Sea Monkey

    Engel makes probably the most efficient units in the industry. Their compressor design does not create a big draw when the unit starts up and draws less than 1 amp/hr when cooling. They can be powered via AC or DC. They are expensive, though...

    I bought a scratch and dent MT60 model directly from the US distributor at a significant discount. It is completely powered by a small wind generator and a couple of small solar panels on my boat and typically draws about 0.4 amps/hr.
     
  16. TnAndy

    TnAndy Senior Member Founding Member

    As you've noted, you can buy a 'standard' ( no ice/water in door ) fridge and get down in the 350kw/hr/year range ( go to the EPA energy star website and check out the specs ) without spending a war pension. That is only 1kw/day. We replaced our 90's model Whirlpool side-by-side 22cuft that used 1200kw/hrs/yr with a GE 25cuft (both ice/water in door) that uses less than 600......that's how much better insulation and compressor technology have gotten.

    Back when solar panels were 8-10watt, the "off grid" fridges made sense......but today, at a dollar/watt, it's cheaper to use a small, efficient 'regular' fridge, and simply add a little more solar to handle it.

    Buddy of mine has an off grid cabin he uses weekends/etc......I put a 1500w solar system in for him ( 6 panels/245w each ) with a 3500w Outback inverter and an 800amp/hr battery bank ( 8--6v 400amp/hr batteries ). The equipment ran about 8,000 bucks. He also has a Kubota diesel generator for backup, but hasn't had to use it yet. The system typically produces 5-6kw/hrs/day. He put a small, efficient fridge from Home Depot in, his cooking is gas, wood is primary heat with propane backup. So far, he has plenty of power.

    You don't HAVE to put panels on the roof.....my own roof is well shaded and no way would I cut the trees ( simply because of the AC value ).....so I went the back of the house, cut a bunch of trees out, and put my solar out there on ground mounts. As long as you have a south ( or near south ) facing slope to your mountain, and enough area to clear to give you a 5-6 hour "window" of sun, you CAN ( and should ) go with solar primary, and generator as backup.

    At the very least, you ought to set up a battery bank and inverter/charger to use with your generator....silly to run a 15kw generator to power a 1/2kw load. Set up the batteries/inverter, charge them once a day (or two), then operate your loads off the batteries. Then when you DO fire up the generator, it's really doing something useful.
     
    BTPost likes this.
  17. d42

    d42 Monkey

    This is a question I had also. I was going to do the dc fridge - Sun Danzer, etc, but as I looked into the cost of the friedge vs the cost of some extra batteries and a regular AC Whirlpool, it looks like the regular fridge might be a better option.
    Thanks to all those who have posted here.
     
  18. reosolar

    reosolar The Solar Guy

    No way that over time a traditional AC fridge will be more cost effective than an efficient propane/ DC Fridge. Spend the money on the efficient appliance rather than to expand your system to support an inefficient appliance.
     
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