This idea has been tossed around here before but mainly focused on what sort of foods to store with an eye to being unharmed by freezing.
The situation is: off grid therefore electric heat is out of the question. The cabin has an acre+ of trees to the south which truly ruins any solar heat as in using air or water collectors. Fifty to seventy percent shade on the south wall and roof. (PV electric modules are located 300 feet south on the edge of the meadow. Propane heat: it would really bother me to leave the cabin empty for weeks on end with the propane wall heater even left on low. Although I would like to do some experiments so I could see how much propane would be used to maintain the interior at something a little above freezing.
There are all sorts of dry foods, pasta, rice, flour, dried beans, potato flakes oninion flakes and powder, etc. that work. Last winter we also stocked some freeze dried foods, mostly meals as well as some f-d green peas, corn and green beans. The veggies worked well enough, being more like the frozen thing, but requiring a modified technique for preparation. The meals were okay, but not something I'd want a regular diet. Maybe I've spoiled ourselves with my regular cooking. ;) We also used dry mac 'n' cheese dinners more than once last winter. :-\ Also on the try it once, eat it if there is nothing else to eat list were packaged "just add hot water" grocery store 'meals'. ::)
Part of the issue with us is that from about mid-December through March, maybe into April, we can not drive the last three miles of road to the cabin. Instead we snowshoe uphill from 8000 to 8800 feet. I do not like to back heavy loads anymore. Sp I/we want/need to have food ready for us in the cabin. Being off grid electric heat is out of the question. The unheated interior temperature dropped to a low of 20 degrees last winter. It was cold enough long enough to freeze 3/4 full jugs of water solid.
We would like to keep a small stock of things like canned tuna, salmon, sardines, chicken, spaghetti sauce, tomatoes, green chilies and green chili sauce, fruit, baked beans, some soups, etc. That's out of the question without heat as glass jars break and cans bulge and may develop seam problems leading to spoilage.
I was mulling ideas over in my head all weekend while we were up there. Here are some of my ideas.
1. Using the excess solar electric to provide heat to keep a small food locker warm. Discarded after a consult with a respected person in the PV installation industry. Also discarded after my calculations revealed that even with all our winter time power generation going into heat our system is too small to be really a good bet. Although, I will admit I have a hankering to do something experimental to see if my calcs are right. d*
2. Variation on the above, using the battery enclosure with insulation added. After all there are 800 pounds of batteries to act as a heat sink/moderator. Discarded for the same reasons. Option 1A is try the excess electric. Option 2B is a little crazy.... see below*
3. Maintain the interior at 36 to 40 degrees using the propane wall heater. I hate thought of all those BTU's being bought and spent and me not being there. Add to that, our current propane supply is limited to 40 pound cylinders, two hooked up at one time through the auto change over regulator. Thus far, they are more than ample for our needs. Having a 200-250 gallon tank would provide enough for low level maintenance heat. However, the propane suppliers all want two sales/refills a year before they will do a cheap rental on the tank. Last year we used something like 100 - 1200 gallons all year.
Now we have some crazy ideas that sprouted from my brain. Pilot lights do not use all that much propane. We run our water heater on the pilot setting only, nearly all the time. With extra insulation it provides us with all the hot water, really hot water, we can normally use.
*2B. same insulated battery compartment. Yes there is unused empty space in it. Build a pilot light burner enclosure that draws fresh air from outside, burns in a sealed combustion chamber, and exhausts through top or end of box. Use a muffler for a combustion chamber? Disadvantage: fuel use. Lots of construction details. Advantages: keeps batteries warm too. Probably have the only one on the block.
4. Build a box cabinet on rollers. It would have one side open. On rollers it could be rolled against the wall over the propane wall heater. With the wall heater left on pilot only it would keep the interior of the box/cabinet warm. ??? Disadvantage: fuel use, need to store it somewhere most of the year when not needed. need to build it.
5. Similar idea, but build a wall cabinet and place it above the wall heater. The shelves and cabinet bottom would be expanded steel to allow air to rise through it. Make a removable "skirt" to fit the space between the heater top and the cabinet bottom. That would duct the heat upwards through the cabinet. Disadvantage: wife not sure of the appearance. Fuel use. Need to build it.
6. Remove insulation from the water heater under the kitchen counter. Leave heater pilot on and the heat from the burner/tank would warm the cabinet space. Disadvantage: fuel use, the work/time required to perform a seasonal change of removing and replacing the insulation.
7. Use the range oven. Light the pilot and leave it burn. Put items that are not to be frozen in the oven. Advantage: no seasonal change over, nothing to build. Disadvantage: fuel use. Not very large, but likely good for our use. Would have to empty oven in order to bake/cook in oven.
After you finish laughing, rolling your eyes, etc. please feel free to contribute or critique.
What's your frost depth there? In other words, could you dig a hole and put a well-insulated trap door/access port over it? Depending on the desired volume for storage and access type, you could approach that a few different ways. Would you want it big enough for human access or simply a container that could be raised via some pulley system like an underground dumb waiter inside a 12" or so diameter pipe? These are some random thoughts, but maybe someone else has actually put something into practice.
When I was a kid growing up in the country in Idaho all the old timers had root cellar attached to there houses that where unheated and they had everything from potatoes, carrots and squash and all sorts of canned goods in mason jars. Put it down in the ground far enough with an insulated top you should be good all winter long. My grand parents used theirs up to 10 years ago when my grandfather died at 91.
A cellar would to me be the most logical. You certainly are not hurting for room or space to build one. How about an insulated box under under the gazebo? How far down in the cistern did it freeze last year? Would that be a fair gauge as to how deep?
Hrmm...
My first thought would be to set up your CC for a dump load, and use it to run heating elements in an insulated enclosure, but it sounds like that's an option which has already been deemed nonviable.
Perhaps build a false bottom on your kitchen cupboards (or in your pantry) that would allow you to install lines through which your pilot-light-only water heater could thermosiphon?
A manual valve tapped into the outlet side of the water heater would allow you to bypass the 'heat-bars' when you're not away, and some very thin rigid insulation placed inside the cupboards should be enough to keep things above freezing when the water cycles through.
True it would involve some construction, but it would be a one time thing and use no more energy than you already use keeping your tank from freezing (assuming you don't drain it every time you leave).
Don, you could build a "hobby" sized solar collector to heat water, which could be used ot keep an insulated cabinet warm. Depending how it worked out, perhaps you'll get the bug to go full scale. Check out Gary's designs over at Build It Solar.
Don off the top of my head at 5:30A would be to build an insulated mini root cellar and use a couple solar skylight tubes to heat it during the day. The insulated portion should make it last til the next days sun. Of course the tube face would have to be elivated above the annual snow fall level. Maybe after I am awake more a variation will develope.
We too have to snowshoe in the last half mile in the winter time with a 400' - 500' elevation change depending on how far I can get with the truck. We leave a few pounds of spaghetti stocked there and only have to carry a can of sauce & bread for few days at a time.
I just haven't found an "instant" beer powder to carry in that is palatable. :)
I know this doesn't directly answer your question but what about buying a used snowmobile? You could then pack all you want and not have to heat anything.
Quote from: Minicup28 on September 13, 2010, 09:21:44 AM
We too have to snowshoe in the last half mile in the winter time with a 400' - 500' elevation change depending on how far I can get with the truck. We leave a few pounds of spaghetti stocked there and only have to carry a can of sauce & bread for few days at a time.
I just haven't found an "instant" beer powder to carry in that is palatable. :)
I keep whisky.
A few of my ideas have been shared here. I read a post a few days ago about a person who built a cheese cellar just by digging a hole. He lined the whole with a large 40 gallon plastic trash can. He put a few inches of insulation overtop. He then packaged his cheese in an additional bucket inside. Supposedly, it never froze.
My concern with the pilot light solution is oxygen. If there is an insulated enclosure around a flame, I could imagine the oxygen getting used up very quickly, then the container just filling with propane.
I would love to see your calculations on the dump load option. 100 watts a day should be enough to keep a fridge above freezing. It already would have insulation from the extreme colds by being in the house. The temperature rise should be too great to keep it above 32.
I think that the oven idea would work for a limited supply of canned goods, jars, etc.
For the long term I would either:
1. Dig a root cellar type pit
2. Build a pantry type area in the main cabin and install a small 8,000 BTU propane heater, set the thermostat at 40F or so.
3. Construct a box out of plywood, insulate it with foil faced foam board on the inside, expanded metal for shelves, use a 40W, 60W, 75W (have to experiment) light bulb based on the size of box. Wire in a thermostat and set at 35F - 40F etc. You can also insulate the outside for extra R value.
We used one of these at the mill, they called it a North Dakota microwave. Except they used a 100 W bulb in a large microwave shaped box and left the light on 24/7......you could get soup too hot to eat.
A cellar would be my first choice..............but there are many ways to skin a cat !
How big is your solar array and batteries and what sort of power do you make a day in winter ?
do you have a sunny enough spot on the roof for a solar heat collector ?
here in the middle east we have passive cooled shelters, rather than a freezing problem.............
but they work on having a large tank of fluid beneath the cabin, deep enough to not get heat from the midday sun.
A small solar panel circulates this cool fluid up and around the cabinet on a thermostat- its a balanced system size of container V's the wattage of the equipment to be cooled.
So taking this as an idea,and not really wanting to store food under the cabin........lets take it the other way arround.
A super insulated food cabinet
Upper fluid solar heater - undercabin insulated heat storage.................could be the same big dustbin in a hole lined with insulation
to be continued......dinner awaits
Don, I would suggest a solar hotbox.
You don't need to keep a truckload of food warm. And you don't have to keep it very warm at that. Don't use your electricity to make heat, use it to move air.
Build yourself a decent sized chest. Don't use your battery enclosure, as you will have to insulate well, and do you really want outgassing batteries dumping corrosive gas on your metal cans?
Build a small, super insulated box. Two layers of 2" foam insulation all the way around. Build a small solar air collector to sit on top, with enough pitch to keep the snow off. Your cabinet would also have to be maybe 4' off the ground too.
Buy a small muffin 12V DC fan, to push air from the collector into the box. You could do it convectively (sp?), but you don't want to overheat either, and I would not know how to shut it off without some active vent controls. You might need to plumb two traps in your air ducting so that the vents enter the box from below to avoid heat loss.
Use two cheapo thermostats. One in the solar collector to only turn on if the temperature is above a setpoint (what's the minimum temp on a cheapie thermostat?). Use another one in the food box to turn off if the box exceeds 80 degrees.
You only need to keep the average temperature in the box above 35 or so. The food will provide a nice thermal mass. Your risk is if you have many days of cloud cover, but I would think that you should be able to survive two days if you insulate well, and we are mostly sunny here! And I bet that on a sunny day it will be no problem at all to get the innards up to 80 degrees. This sounds like a fun project.
well the last post is similar, but i was thinking liquid filled, as with air you will need to be close
fluid hold heats longer and will travel further.
daytime like the above post using the day time highs to heat all the goods in the cabinet, fluid circulates from roof to cabinet uisng a small PV cell and direct to a pump
Night you use the cellar resorvoir if required,using the existing PV system
If you wanted to get technical............during the day depending on the panel temp- storage temp and the lower resorvoir, the roof heater could also circulate down into the lower resorvoir to store any extra heat developed in the day.
That would mean some smart wiring - relays and thermostats........probably more than you want to do but would make a nice project !
I just thought of another idea. I know that solar is out of the question for you. You could also build a compost heated box. With some good insulation it will always stay above freezing. You might even be able to use a scrap chest freezer. The only problems are with proper sanitation. You would have to carefully separate the compartments or build them as two separate containers and pipe antifreeze between them. I just don't know how much electricity this would require.
I agree with those who've suggested a root cellar. Very old technology with nothing to break down is usually better than a hi tech one. It also provides something of an emergency shelter.
I know its fun to come up with all of these solutions. Don, your problem isn't food storage, its food transportation. Unless you are just itching to solve the food storage issue, I think you should look at transportation. The transportation won't go out while you are away from the cabin. It won't spoil while you are gone. It doesn't involve a fire risk to your cabin while you are gone. It won't have an electrical fire while you are gone. etc......
Just saying.
If you own the land along the path that you take when the snow makes it impassable, then consider the following. Make a miniature ski lift just for your packs. Have the motor for it powered from your car generators. Put marker tags on the cable so you know when it reaches the top. Allow for tree growth.
This needs to be carefully thought out, but should work.
I also second the root celler idea. Suposedly if you get down far enough, the temperature should stabalize at about 55 degrees.
That and plenty of insulation.
Hope this at least gives you a few laughs.
Bruce
Thanks for all the replies, thoughts. I'm mulling things over.
A couple notes:
Snowmobile is out. Tried that, it didn't work well. Too much distance that winds around slopes. We'd need a snow machine made more for virgin snow transport use and in NM those are not common for used and it's too many $$ to buy new.
I've thought of using the hot water from the water heater on pilot. BTW, we don't leave it on all winter. Yet.
A cellar could be done next year. My friend/neighbor with the equipment has taken the backhoe down from the mountains already this year. I'm not digging by hand.
Using solar is doubtful. It's the trees, 55 to 70 ft ponderosa pines. With the cabin at the top of a ridge that falls away to the south, in the winter the sun's low angle has it struggling through the tree tops all day. There is always some sun, but quite often more shadows than bright spots. I intend on monitoring that a little more closely this winter when we are up there. Maybe it would work with a larger than necessary collector?
If I was doing solar heat collection I believe I'd do a water/anti-freeze system. The water would be useful as a heat sink as somebody pointed out. Pritch and UK4x4 There is power available for a small circulation pump. Where to place the collector for best results is the question.
Compost heat is not going to work. The composting toilet freezes as it is.
Bruce, we can always count on you for innovation. All but 1/4 mile of the distance is forest service though. They might not be amenable to that.
Thinking/listening hat is still on. :)
Hmmm, if you could get your hands on a small amount of plutonium. d*
Could you do a glycol filled black water tank with a passive flow to a small radiator in a box? Another thought would be a solar panel hooked directly to a peltier cooler/heater.
Quote from: phalynx on September 13, 2010, 11:36:41 PM
Hmmm, if you could get your hands on a small amount of plutonium. d*
Could you do a glycol filled black water tank with a passive flow to a small radiator in a box? Another thought would be a solar panel hooked directly to a peltier cooler/heater.
Peltier is out, as it is too lossy. An electrical heating element is about as close to perfect as you can get for converting electricity to heat.
If you can't use the sun directly, I think you either :
1) Need to burn something. Costly
2) Need to dig a hole. NRE, but labor intensive
3) Build an insulated box and use your excess electricity from the big solar panels. (Hey... can you run a small AC powered freezer in "reverse" and switch the source and supply lines on the compressor to keep the food warm instead of cold?)
Don,
If you do make a solar collector, you could run a loop under the composting toilet as well.
Could you use one of those large heater / coolers that the truck stops carry? I don't know how much they draw but you might check that out. Actually the old style cellar looks the best to me. Especially anyone that might be looking at living in their cabin year around or might have to move there because of tough times should have a cellar. Okay I am a realist or is that a survivalist. Build it and you can always use it for a bomb shelter. :) Hey if nothing else grow mushrooms.
Thanks Don! Here is another of my crazy ideas. If you mounted
a solar panel on a pole and managed to mount the pole to the top
portion of a tall tree, you could get more dependable power.
Of course, you would need to find a good tree climber to do this.
Bruce
The more I think about this the more I think that a hole in the ground, a root cellar or a solar powered liquid collector system may be the best long term solution, although I still have an inclination to investigate just what the excess electric could do with a well insulated and heavily heat sinked box/cabinet. ???
For those who still think solar is the way to go, here's a sketch that may help explain my doubts about the efficiency let alone the efficacy....
(https://i139.photobucket.com/albums/q305/djmbucket/solar/solarslope.jpg)
South is to the left. Winter sun is low as drawn. Even with higher sun angles we have lots of shade on the cabin and most nearby areas. Further south, about a 1/4 mile from the PV panels the ground rises to a height about the same height as where the cabin is.
As far as digging goes, would it be easier to dig in instead of down. It looks as if you have a pretty good slope there. Or maybe build a small concrete structure and push the dirt over it from above.
Ok. Let's think about the calculations of electricity to heat. For all assumptions, let's assume that this is going to be an insulated box. My initial reaction would be to use an old chest freezer. Insulated, easy to clean, and many times free. The cost of a 2 inch thick home built box would probably cost much more in materials and time.
Would it be more efficient to heat the box directly through a resistance heater or some type of home built heat pump?
I think you said that the lowest temp recorded was 20 degrees F. That means that you only have 13 degrees temperature rise. Most fridges and freezers have to combat 2-5 times that in temperature drop.
What is your excess daily production? IIRC, you have 3 200 watt panels and should get at least 2 hours of sunlight even in the winter. Seems like you would have at least 200-300 excess watts a day. That would be around 600 btu.
I was trying to find a conversion for air, and I found this:
http://www.gas-lights.com/form.html
It gave me this answer:
For a temperature Rise of 20 degrees Fahrenheit,
In a space of 8 cubic feet,
Your BTU requirement is 21.28 BTU's
It seems like a small heater should very easily be able to heat a small 2x2 box by 13 degrees with your excess electricity. My concern would be overheating. Considering that the purpose of heating a small box would be to keep water from freezing, there should be plenty of thermal mass already from the food to maintain stable temperatures over time.
Here is a couple of other things that I remembered from my days on the farm in idaho. They had something call the poorman's rootcellar which was basically an old chest freezer buried in the ground covered with straw.
Another thing I remembered was a program that I saw on homesteading in alaska and some body had a fishing camp. To keep things from freezing they dug a 2X2X4 hole in the ground. They then put a foot of horse manure in the bottom. They then put in one of the old styrafoam ice chests on top of the manure with holes cut in the bottom of the ice chest. The whole thing was then buried in dirt. As the manure breaks down it generates heat and keeps things from freezing. The down size was that you had to clear the dirt off when you wanted to get something out.
Thanks for that squirl. I've run across a couple of those calculators in the past. I'll be first to admit I was figuring on a larger space because there has to be enough mass to act as a heat sink to help keep the temperature from late afternoon when there is no power excess through the night till maybe noon or so the next day. That's one advantage of using the battery locker; 800 pounds of heat sink.
(Each day the PV charging system goes through a bulk recharge cycle, then spends a little time in ansorb until the batteries regain float voltage. That could be before noon on a good day, later if it's cloudy and /or snowing.)
However, I find those simple calculators suspect. They have no input for insulation so does that mean an insulated box will perform better than the calculator result? Or is that calculator based on some unknown 'standard' wall? It also has no time factor. BTU's are time rated, as in so-many BTU's per hour, same as watts or KwH. How is mass and heat input for a limited time taken into account?
I'll come back to this later. Thanks.
The low temperature of 20 degrees that I mentioned was the cabin interior temperature. The exterior temperature makes it into the single digits, 8 or 9 regularly during the coldest. This is according to data from the past half dozen years. Historical data has the lows dipping into the minus singles for several hours a night, but that has not happened much at all since 2001, the oldest area records I have access to. So any storage placed outside the cabin has temperatures of maybe 8 degrees F to deal with.
Solar production: Here's what I looked at. There's a remote weather station a few miles from our cabin. The weather conditions are similar even with the 800 foot elevation difference. That station collects many data types, one is solar radiation, in watts per sq. meter. The solar radiation value used when testing and rating PV modules is 1000 watts per sq meter. So if the weather data indicates that at high noon (actually 12:08 at my station) the solar radiation was 638 watts/m*m, simple math shows me that the most power my 624 watts worth of panels could produce would be 399 watts.
I do have data collected by the charge controller. Summary data such as KwH put into the batteries. That runs at about 0.3 Kwh a day when we are not using the cabin. That would require a little more power from the panels due to charging loses in the batteries.
I chose a typical recent January. Looking at the solar data, most days the power generated before noon should be sufficient to ensure the batteries are full. This is borne out by personal readings on mornings when we arrive after having been absent for several days or more.
The next step was to do the math to add up the watt-hours that would theoretically be generated until late afternoon when the output generally would fall to a figure of 5 to 10% or less. I selected 10 random January days and came up with an average of 1.25 KwH that could be called excess power.
My conversion calculator indicates that 1250 watts/hour is = to 4267 BTU/hour
averaging 4267 BTU/hour out over a 24 hour day = 177 BTU/hour
OR
1250 watts/hour averaged out over a 24 hour day = 52 watts/hour
However, the excess power is not available spread over 24 hours. The excess energy is produced over 5 hours and therefore must be stored in some sort of mass, concrete, water, something.
Not only that when I was calculating the average data I did not select any cloudy days. There were not that many of them and the exterior temperatures were sometimes actually higher than clear days. The cloudy days though, most often came in sets of two or three days in a row. So that would be two or three days, during which the container would cool down. How far down, I don't know. Guessing at what the container inside temperature would be, is just a guess.
Using a calculator similar to the one squirl provided I came up with a theoretical value of 167 BTU/hr for my battery locker. That seems to be too close to the the theoretical calculation for the excess power. Too close for comfort and too close to allow for a three cloudy day factor.
I realize that a smaller space would require less heat to keep warm. However there is the issue of needing it to be large enough to contain sufficient mass, plus whatever heating equipment is involved, plus the food items we wish to keep from freezing. On the subject of heating equipment one of the more workable heating loads would seem to be a resistant coil designed for water heating. That could be used in a small tank filled with anti freeze solution 'just in case'. That adds to the heat sink and also takes up more space.
Anyhow, possibly there is some defect to my reasoning process. I think I'd welcome that as long as the surplus numbers came out more favorably.
???
Perhaps I should link this to the Off Grid topic?
:o whoa!
So I figure let's have a look at what sort of dollars I'd have to put out to take advantage of this free electricity.
water heater element, 24 volt 600 watt ....................................................................................... $70 to $110
120/240 volt won't work or you need a whole bunch of them. Ohm's law thing.
thermostat, water, ... $20
relay, solid state; use with charge controller to turn heater on/off when excess power is available .......... $70 to $100
that's $160 to $240 not to mention the cost of a water tank, insulation, fuse, etc. etc.......................
That makes me go back to square one (more or less) and stash some canned goods in the oven with the pilot light on. Last year we used less than $80 worth of propane for the entire year's worth of propane to cook, heat water, operate the refrigerator and warm up the cabin with the wall heater! (we used the wood stove for primary heat).
But a part of me would still like to use that 'wasted' electrical power. ::) Call me nuts. d*
I think you are missing that the food itself can be the thermal mass. If the food didn't have water in it, you would not have to worry about keeping it above freezing. This is why fully stocked fridges and freezers require less electricity and fluctuate less in temperature. Fluids make excellent thermal mass.
Also, I have seen many cheaper 12v heating appliances. for $10-$25. Off the top of my head they are air heaters from Harbor Freight, coffee cup water elements, and heating blankets. Most of these products can be picked up at the local Wally world. I used to have to keep my eye out for these. I had an older jeep.
A well insulated box with a small heater on for 2-3 hours should keep the food above freezing for a day or two, especially if it is indoors. Personally, I would worry more about overheating. It sounds like a fun experiment.
That hole in the ground is looking better and better ;D
What about a passive solar 'box' (something like a greenhouse) over by the pv panels? THen you could install an incandescent light, 60w solar power system and a cutoff to protect the battery.
Maybe even a timer so the light only comes on at night.
Some cheap aluminum windows, 6" walls, black concrete wall on the northside with 6" wall behind it and all heavily insulated with a STRONG shed roof so the snow would bury it and not collapse it.
With enough southern exposure the windows would heat the black wall with the sun and the concrete wall would retain the heat for a long time augmented by the light.
Well insulated it will likely remain above freezing.
My neighbor tells me that even in 10 degree weather his uninsulated porch can get to 60 degrees because of the greenhouse effect his windows on the south provides. He plans to insulate and make it a green house.
Quote from: OlJarhead on September 15, 2010, 10:52:53 AM
What about a passive solar 'box' (something like a greenhouse) over by the pv panels? THen you could install an incandescent light, 60w solar power system and a cutoff to protect the battery.
Maybe even a timer so the light only comes on at night.
Some cheap aluminum windows, 6" walls, black concrete wall on the northside with 6" wall behind it and all heavily insulated with a STRONG shed roof so the snow would bury it and not collapse it.
With enough southern exposure the windows would heat the black wall with the sun and the concrete wall would retain the heat for a long time augmented by the light.
Well insulated it will likely remain above freezing.
My neighbor tells me that even in 10 degree weather his uninsulated porch can get to 60 degrees because of the greenhouse effect his windows on the south provides. He plans to insulate and make it a green house.
OJ I think that the amount of snow in that area during his absense would restrict the sun penetration into the window. Thats what I had mentioned in my earlier post. I suggested using a solar " tube skylight" but even this would have to be elivated several feet above the actual top to keep from being covered over by snowfall.
Root cellar.... and latching storage boxes. You will not be the only mammals who notice the relative warmth of the root cellar. Anyway in the winter you can thaw out in the cellar after walking in while the fire is heating up the cabin! :)
Well, I think we should dig a hole back into the hillside. That will wait until spring or early summer though as my neighbor with the skid steer, who will work for us for fuel, has a project going on that has removed the skid steer from the mountains for at least a month.
However, I have thought out a way to test out the excess solar output manually without spending a lot of money. I need to locate an old freezer or refrigerator box first though. I'll have a look at the local freecycle site as soon as I figure out what my login is. d*
Don,
I'm not sure if you're going the same direction, but last night I had a different idea. Rather than expend energy trying to prevent freezing, perhaps you could use it to assure freezing. If you were to take an old freezer (outside but roofed against snow/rain/sun) and keep frozen food such as vegatables, meat and the like. Your winter weather will usually keep the food frozen so the freezer wouldn't need to cycle to maintain temperature. Short warmer periods would be defeated by the insulation of the freezer and thermal mass of the food. The only time the freezer would need to use energy (propane or electricity) would be during periods of sustained warmer weather.
12 Volt bed warmer already has a thermostat, just need to add a timer to only come on during the afternoons when you have the spare power.
Under $100 us- adds to existing system- timer should not be that expencive
low wattage- low heat.
In walmart they also have a 3 way vehicle 12 v adapter with a battery saver circuit too, I use one in my truck with my 12v fridge, works perfectly to protect your battery bank < $ 10
Quote from: Phssthpok on September 13, 2010, 01:15:22 AM
Perhaps build a false bottom on your kitchen cupboards (or in your pantry) that would allow you to install lines through which your pilot-light-only water heater could thermosiphon?
A manual valve tapped into the outlet side of the water heater would allow you to bypass the 'heat-bars' when you're not away, and some very thin rigid insulation placed inside the cupboards should be enough to keep things above freezing when the water cycles through.
True it would involve some construction, but it would be a one time thing and use no more energy than you already use keeping your tank from freezing (assuming you don't drain it every time you leave).
I have located my propane adapter!! :) :) This weekend I'm going to run a pilot only test on the RV water heater using a disposable propane cylinder. I'll weigh a cylinder, record the start weight, and check every so often. I believe the cylinder will last longer than the weekend. Anyhow, we'll see how much gas gets burned in what time period and then extrapolate the data. Full report later.
A loop with a small aluminum oil cooler in it could likely succeed as a thermo-siphon radiator to heat the under cabinet space. I have one of those lurking someplace in the attic storage IIRC.
Maybe I missed it, but... Back when I was doing a good deal of expedition climbing in Alaska we would bury our caches about 3-4' deep in the snow. Snow is an excellent insulator. Have you taken this into consideration?
I'd think that the partially buried refrigerator (use some popcorn packaging foam for backfill) with an above ground substructure (thinking of a "double door") insulated with 4" foam insulation glued into place and heated by the heating element out of a DC cup warmer would do the trick nicely....if it snows, you will have even more insulation. Any cheap refrigerator off Craigslist would work. Betcha that the total cost would be under $120. Just think of the $$$ you'd save by not having to plan on buying a plot at the funeral home...
DLS, we can't depend on snow. It may snow 3 to 6 feet in a winter, but daytime temps go above freezing with some regularity and it does melt down. It would likely help for a couple months of the winter.
Okay now, FWIW the propane pilot test happened this weekend. I started the Suburban brand RV water heater, 6 gallon, Saturday afternoon. The control was set to allow only the pilot light to be lit, no main burner. I had a 20# tank hooked to one side of the changeover regulator. The other side had a Coleman disposable cylinder hooked up with an adapter. At 4 PM Saturday I switched the regulator to the disposable cylinder. Monday at 2 PM I switched the disposable cylinder out of the system and removed it.
The disposable cylinder weighed 304 grams less at the end of the test.
304 grams for 46 hours of operation = 6.608 grams per hour.
6.6 X 24 hours = 160 grams per 24 hour day.
I'm going to round that up to 175 grams per day.
175 per day X 30 = 5250 grams per month; 11.57 pounds per month
At 4.24 pounds of propane per gallon that would be approximately 2.75 gallons.
So one of my 40# portable tanks should last about 3.6 months if feeding only the RV water heater on pilot light only.
??? ???
Wow! That's a lot of gas.
Still think it might be easier to keep frozen food cold. . . ;D
Quote from: MountainDon on September 20, 2010, 07:20:45 PM
175 per day X 30 = 5250 grams per month; 11.57 pounds per month
At 4.24 pounds of propane per gallon that would be approximately 2.75 gallons.
So one of my 40# portable tanks should last about 3.6 months if feeding only the RV water heater on pilot light only.
??? ???
Not to nitpick but depending on your refiller there is a good chance that your 40# tank could be only filled to a max of 80% per stated tank capacity so figure on 2.8 months of run at previously mentioned consumption. I hate to say it but it might be worth actually weighing your filled tanks occasionally and making sure you actual get what you think you are paying for.
Experiment in progress.... link from here....
http://countryplans.com/smf/index.php?topic=2335.msg123471#msg123471 (http://countryplans.com/smf/index.php?topic=2335.msg123471#msg123471)
Sorry for the resurrection of an old topic but I found this thread quite interesting. The root cellar idea I think has merit and doesn't have to be complicated.
http://extension.umd.edu/publications/pdfs/fs803.pdf
Is a good publication and even mentions just using an old barrel or building a box. The publication talks mostly about storing vegetables but storing canned goods would easily work as well.
Thanks for that!
Late comer to the thread. Loved the plutonium idea. Got me thinking. How about a wench (I didn't misspell winch) to transport the stuff? I'm trying to think outside the (thermal conditioned) box.
I was looking for ways to keep my horse's water trough from freezing with out power. One way was to bury a pipe 48 inches below the frost line insulating it above the frost line. And ground heat coming up the pipe would help keep it from freezing. You may be able to make your insulated storage area with a ground heat pipe coming into it to keep it from freezing.
QuoteThe upright pipe to your tank or waterer must also be well insulated. Some companies sell an insulated earth tube that can be put down the hole where your riser pipe comes up. This 16-inch-diameter tube is made of two-inch styrofoam and helps insulate the pipe. Ground heat will then surround the pipe, even above ground level.
If you dig a deep hole, down past the frost line—an extra four to six feet down past the water line itself—this generates ground heat for your riser. The hole enables warm air to come up through the insulation tube around the vertical water pipe and keep the water from freezing. Ground temperature below frost line is usually 48 to 56 degrees. The earth tube is durable PVC on the outside and foam insulation on the inside.
I have 2 40 gallon "sheep's troughs". 10' of hose, and a yard hydrant. The yard hydrant does not freeze, the hose gets disconnected and drained after each use. When one trough gets about half full of ice, I flip it upside down and start using the other one. Generally, by the time the ice has filled the second trough 1/2 way, it has fallen out of the the first one, and I start over.
The size of the trough and the half full rule just speaks to what I can flip by myself.
I've only had one time in 6 years when the weather stayed so cold that this didn't work. You may be somewhere colder than Western Washington state, could lift more, etc, etc.
Yard hydrants work well here. They are basically faucets that stick up out of the ground on top of a pipe that is connected to the water supply. When they are turned off and the hose disconnected, the water falls back down the pipe to the level of the supply line. If the supply line is below the frost line, the water supply won't freeze up.
For me, so far, so good. :D