no Fridge: cold room/pantry/ice box?

Hi all, first post here, very exciting!

I'm about to build a tiny house and am trying to find ways of making my lifestyle as off-grid as possible. I would love to not have to buy a new fridge and the one I currently use is ginormous, inefficient and makes creepy whining noises intermittently. It's not coming with. I have a huge garden which I am starting to get a reasonable amount of food from, and expect it will improve each year (only been on the property just under a year) and an equally huge root cellar perhaps 50 steps from my future front door as well as a greenhouse. I'm working towards eating from the garden primarily and eventually the root cellar/greenhouse in the winter/spring as well as pantry items, and only making enough food for a meal or perhaps 2. My main fridge items are things like a pint of cream which I would only need to keep for 2 or 3 days tops, cashew cream, perhaps some cheese (not sure that even needs the fridge), and any leftovers. I probably will have a small freezer or a chest freezer either in the house or greenhouse.

What I'd like to do is put a pantry/cold room on the NE corner of the new house where the kitchen is located but can't seem to find any precedent to look at for guidance. Perhaps I'm better off just buying a really great cooler or zeer pot for the few things I would need refrigeration in the house for, or *gasp* walk the 50 steps to the root cellar to cream my coffee in the morning. However, mud and pajamas don't mix well.

Regardless of its ability to keep dairy products fresh, I do need a space cooler than the pantry to store onions, garlic, and canned goods, so back to the original idea of a cold pantry area: The whole unit would be about 2' x2' '8'. It sits on a concrete slab, which I imagine will radiate some of the coolness of the ground. If the top 5' was regular pantry, could the bottom part stay cooler if it were made out of brick, perhaps with a vent to the outside that could be opened at night? Even in the summer, the temp often gets to 50 at night, and winter in the teens or 20's. Would some insulation be needed perhaps on the outside of this using the brick as thermal mass, insulated from the main living space and the above pantry? What kind of insulation? I suppose I could use light straw outside but if anyone knows of something like foam board that's not made of poison that would be sweet.

I'm looking for the simplest possible solution, and realize that there are some plans for refrigeration using piped well water, but honestly I'm not up to something like that. I'm really hoping more to understand how to build a tiny, integrated ice box if anyone has experience or conjecture. Thanks!

Have you considered an Ice House?

Paul Wheaton has a video refrigeration without power - the cool box that shows some promise.

A small solar PV system could be installed to operate a small electric fridge. Prices have fallen dramatically in recent years.

Thanks Ken, those were my initial ideas as well, however the ice house concept seems like a much bigger (and outdoor) project than what I'm hoping to achieve here, and the cool box is interesting but again involves a whole bunch of piping and plumbing which I'm not able (or perhaps more the case is willing) to do. I'm looking for a way to get this done 15th century style, so to speak, basically just using natural materials, sort of in the spirit of a super tiny root cellar indoors.

I forgot about Zeer pot refrigeration.
So easy a caveman could do it.
Might be just the right thing to get you by.

There isn't a great AND little solution.

A really good cooler and ice blocks (frozen water jugs) that you bring in from the chest freezer every couple days will keep the cream and a meal nice--you know one of those heavy marine coolers.

An ice house is a big solution--but a pretty cheap one if you are in a cold enough climate to make your own ice in the winter--and not bad if you have to buy it. My Amish friends down the road built one, probably 12x12 total with blue foam insulation and used tin siding. He spent a little over a grand and $400 to buy the ice for the first year. I can't run that much fridge and freezer for near that cheap.

The two together would get you what you need.

I've tried the zeer pot, and it doesn't really work in Kentucky; as it's generally too humid (above 80% all summer unless it's actually raining) to work well enough. I discovered the little water sealed & inverted butter crocks a couple years ago, and have used them since. But just about every summer I try something a little different for mostly off-grid refrigeration. This past winter, I learned about something called a "space refrigerator"; which is basicly a a "funnel" type solar cooker that is aimed due north at about a 30 degree inclination. So that it *never* receives direct sunlight, and is largely protected from the infrared radiation from buildings & trees, particularly at night. That actually works well enough to make a "cool" box, but works best on clear nights because clouds reflect IR; so it's as much dependent upon the weather patterns in one's area as anything else is. You just can't expect it to work reliablely, nor do better than about 20 degrees F below ambient temps.

However, the space refrig thing gave me an idea. The calculations for the space refrigerator pointed out that a great deal of heat gain for a refrigerator of any kind is actually IR from the immediate environment, so anything that one can do to reflect IR away from your cooler will improve the functions of whatever method you use. So I set out to make a "space tarp" that I could drap completely over my 5 day cooler, by gluing a mylar emergency blanket (shiny side up) onto a section of discount canvas from Walmart. The canvas was to impart real blanket like qualities to the space blanket; heavy enough to hang readily over the cooler and not blow off during the tinyiest of wind gusts (still might blow off in a good wind, but hasnt' yet), quiet enough when handled to not annoy my wife. I used 3M brand spray glue to attach them together, and then trimmed the edges down so they didn't frey.

Well, this Saturday was my mother-in-law's birthday, and my wife wanted to have the family over for a cookout/birthday party. So I took the opprotunity to run my experiment with the solar tarp, to see if it improved things. I set up the 5 day cooler on the deck on Thursday evening, and put about 100 pounds of ice into it (it's a pretty big cooler); 2/3s was block ice (frozen gallon jugs of tap water) and the rest was cube ice. I also put about 100 pounds of canned drinks into the cooler, but I deliberately stacked them on top of the gallon jugs of block ice, because I didn't want water convection to cool the drinks; I wanted to see how well air convection would do. I deliberately left the solar tarp off overnight. The next morning (about 11am) I checked the top of the cooler (in full sun) and it was about 90 degrees, and the top 2 layers of drink cans were warm to the touch. The top row was about 60 degrees. I closed it back up, and laid the solar tarp across it.

The next day (Saturday) I uncovered the cooler, again around 11am and in full sun. The top of the cooler was about 60 degrees, and the top row of cans was just below 40 degrees. I've redone this check every day since, (the party went well Saturday, most of the drinks are gone) and the ice persists as of Monday. It doesn't look like the ice will be yet melted for several more days at the current rate. The last time I did this was two years ago, and in complete shade, 100 pounds of ice lasted 4 days in the 5 day cooler. (They always overestimate).

I'll keep tabs on the cooler, and post here again once the ice is gone; but regardless I'm convinced that this little project was worth the $3 dollars or so of vested materials.

Some thoughts:

1) The closer to cubical you make an insulated box, the better it will perform.
2) Insulation is your primary resource when it comes to keeping things cool.
3) If you have a freezer, siphoning off some of that cold to keep an insulated box cool, shouldn't be too hard. Easy way, switch a frozen jug of water from freezer to icebox every day or so. More hands-off way, run a loop of tubing filled with propylene glycol (antifreeze) mix between the two; pump it based on a temperature sensor.
4) Insulations: Polyisocyanurate board is the readily available option. Vaccum Aerogel is the high-tech, high price option. Roxul or foamed glass blocks are fairly low-pollution wise.
5) Ground coupling will get you down to the average annual temperature where you live. Getting colder than that gets energy intensive, as the ground is a near infinite source of that temperature.

Got any running water on site? You could use a trompe to make cold compressed air.

Michael Cox wrote:Got any running water on site? You could use a trompe to make cold compressed air.

What is a trompe, and how do I do that?

It is a device made of plastic pipes set into a stream. It makes a steady flow of compressed air with no moving parts. If you don't have running water though it won't work for you. There is a thread about the on here somewhere.

I looked that term up on Wikipedia, and while I do have a seasonal stream that crosses my propery, the head drop measures less than a foot. So it's not worth pursuing for me.

Tessa, I also have considered a cooled space for long term food storage including my wine. The only system I've considered that can produce good results would rely on a vapor compression unit. The simplest configuration would be to place a small chest freezer in the space with the condenser coils outside. Alternatively, the freezer might be outside the space completely. The freezer should be loaded with water bottles that are to be frozen. Duct work is fashioned along with a dc case fan to circulate air in the space through the freezer where it is cooled by the frozen water bottles. Put a timer on the fan so it operates primarily during the day. This would keep the temperature in the freezer above the setpoint while the fan is operating and allow the freezer to be powered directly from the solar array to avoid some battery discharge during most days. Let the thermal mass and insulation of the space carry the unit to the next solar day as this will avoid some unnecessary battery discharge. Also, set the freezer thermostat to the lowest setting since its purpose is only to freeze water - there is no need to take the temperature down any lower than necessary to fully freeze the water.

I remember as a child we had a pantry; We were poor miners and did not even have a fridge until I was 5.
The pantry was on the north side of the house and basically was a cupboard where the outside wall was very thin . It also had a small very thinly glazed window near the top, marble shelves ,the door was thick heavy we tried to keep the pantry as full as possible with all our stored food tins etc as a thermal mass only for cold . In the summer we kept milk butter etc in there on the bottom shelf no problem. I would look at very old houses in your area and see what they did . People forget that many of the problems we face today are not new
Another example of what you can do can be found in John Seymor's books


David

This post is late because My wife and I took the kids to my sister's lakehouse for a couple days this week; sorry, we were having to much fun for me to remember to post this.

In the end, there was a small amount of ice left in the cooler on Wendsday evening, and the drinks were still cold on Thursday morning. So that's 6 days in a 5 day cooler. While this isn't scientific at all, the last time I tried this I could get 100 pounds of ice to last only 4 days. I think that conditions were close enough to each other to make this difference in ice longevity meaningful, and that roughly $3 in materials was worth it to me. It's ugly as hell, though, so if I discover that someone makes a pretty one, I might buy that one to make my wife happier about it.

Something strange did happen though. The relative humidity hit about 80% for a couple days in there, and I discovered that dew condenses under the solar tarp on the surface of the cooler. And not a little, the canvas portion of the tarp stayed wet far too long. If I were to do it again, I'd use a type of cloth that would wick away, and hopefully not encourage molding. Perhaps a wool blanket from the Army/Navy surplus store. The covered surfaces of the cooler stayed in the 50-60 degree range for the duration of the test. Ironicly, I had a very local power outage at my place this past Monday (due to an infrastructure failure issue with my meter base) and didn't have any ice ready because I still had almost all of my block ice bottles in the cooler, unfrozen. Which was terrible timing.

Creighton Samuiels wrote:The relative humidity hit about 80% for a couple days in there, and I discovered that dew condenses under the solar tarp on the surface of the cooler. And not a little, the canvas portion of the tarp stayed wet far too long. If I were to do it again, I'd use a type of cloth that would wick away, and hopefully not encourage molding.

That condensation also increased heat (970 BTUs / pound of water). Ideally, you would want to evaporate that again, to get your 'coolth' back.

Thank You Kindly,
Topher

Ben Hewitt blogged about a nice solution repurposing an old ice box. Of course, he lives in Vermont. It would probably work 9 months a year even here.

Ann Torrence wrote:Ben Hewitt blogged about a nice solution repurposing an old ice box. Of course, he lives in Vermont. It would probably work 9 months a year even here.

I consider that actually several kinds of stupid, if you already have grid access for other power needs anyway. Not only is the modern compression cycle refrigerator incrediblely efficient, any heat that it does produce helps to offset the winter heat load of the home anyway. Cutting holes into the envelope of a home for an indoor cool box creates thermal bridges from the cold outside to the heated inside. I'd wager that this guy spends more BTU's on heating his house in winter, as a direct result of cutting thermal bridges into his home that he did not require, than a modern refrigerator would have cost him all year.

We were without a fridge for about 2 weeks when ours broke. We did very well, using only a tiny dorm room refrigerator until the big fridge arrived. The tiny fridge kept the milk, eggs, and ONE nights leftovers good. The produce lived on the counter and the mayo was thrown out.

The bag of apples was good after 2 weeks on the counter but had lost some crispness. The head of cabbage was good for a week but a couple of the outer leaves were wilted: I just peeled off the outer leaves and used the rest. The onions were good for the full 2 weeks. The potatos were good after 2 weeks. The vinagrette salad dressing was good after two weeks and I used it as a dressing for the cole slaw, which used up the last of the cabbage (The first piece of cabbage, along with an onion, went for a stir fry to use up the last of the leftover beef).

Ann Torrence wrote:Ben Hewitt blogged about a nice solution repurposing an old ice box. Of course, he lives in Vermont. It would probably work 9 months a year even here.

As an example of how silly this concept would be for the vast majority of us, please refer to this study...

http://www.cchrc.org/passive-refrigeration

Please note that, in Alaska, a study done on a hybrid refrigerator (passive when outdoor temps were below necessary fridge temps, compression refrigeration otherwise) over the course of a full year found that the hybrid fridge was only 16% more energy "efficient" than a modern, Energy Star rated gas compression refrigerator. In Alaska. And this study didn't even attempt to determine how much building heat was lost as a result of the penetrations of the building envelope required for the passive portion of the hybrid fridge. Granted, if you actually live off-grid and heat your home with something other than fuels that you have to buy (or have a practially unlimited supply of firewood), then a passive fridge might be a wonderful investment. But if you pay money for heat or don't like cutting extra firewood, and have access to the power grid, a modern & efficient compression refrigerator is a perfectly valid energy choice even in very cold climates.

Creighton Samuiels wrote: Granted, if you actually live off-grid and heat your home with something other than fuels that you have to buy (or have a practially unlimited supply of firewood), then a passive fridge might be a wonderful investment. But if you pay money for heat or don't like cutting extra firewood, and have access to the power grid, a modern & efficient compression refrigerator is a perfectly valid energy choice even in very cold climates.

I don't think the Hewitts are completely off grid, but they do heat with wood they harvest from their own land.

BTW, 16% reduction sounds pretty good for the heaviest load among my energy consuming appliances. I myself am planning to penetrate the envelope of my house at some point, similar to this thread, only above ground because our water table is too high. Doing so will allow me to have a cold space far larger than I would care to refrigerate, one that is resilient in times when the power may fail.

I believe the OP asked for suggestions for a small, off-grid solution.

Ann Torrence wrote:I myself am planning to penetrate the envelope of my house at some point.

I recommend as few building envelope penetrations as possible, since each one comes with it own heat, air and moisture losses; and commensurate increased risk of problems. Consider having a fridge substitute outside (root cellar, cooling box, whatever).

If one is determined to breech the envelope, make the hole as small as possible, This means cool with water rather than air if one can. A coil of pipe 5' underground (in my climate) would give me 48°F water all year round, for the price of energy to run a pump, and 2 small holes in the envelope.

Thank You Kindly,
Topher

Ann Torrence wrote:I believe the OP asked for suggestions for a small, off-grid solution.

You are correct, of course, and a cool box does work somewhat well for some latitudes as an off-grid fridge for part of the year. However, rather than a hybrid fridge with pentrations for air flow pipes, consider getting one of those DC marine refrigeration kits, and turning an old ice box into a fridge with a condensor outside, running on a solar panel or two. If you put the evaporator in the section of the ice box that was reserved for ice, as well as several gallons of water in a container, there's a decent chance that the jugs of ice will keep the ice box cold overnight. And with the condensor outside, you'll benefit from the natural cool of northern climates anytime the daytime outdoor temps are below about 55 degrees, not just below 40.

We are currently building a cold pantry by plumbing the main water line into the house through the cold pantry. The 1" main splits into 4 5' coils of 1/2" copper pipe and an aquastat controls a computer fan at the bottom. This is in the NE corner of our basement and is insulated with R-23 Roxul batts and a salvaged walk-in cooler door. Preliminary testing is very good, but no real life results yet as we are still remodeling and haven't moved in.

Bill Bradbury wrote:We are currently building a cold pantry by plumbing the main water line into the house through the cold pantry. The 1" main splits into 4 5' coils of 1/2" copper pipe and an aquastat controls a computer fan at the bottom. This is in the NE corner of our basement and is insulated with R-23 Roxul batts and a salvaged walk-in cooler door. Preliminary testing is very good, but no real life results yet as we are still remodeling and haven't moved in.

That's brilliant!