From Flu Wiki 2

Forum: Refrigeration

11 March 2006

Nanita – at 21:11

If we loose power, how can we keep things cold?…I do have a generator(a necessity in hurricane country) and gas tanks. I plan at the first sign to get my tanks filled so as to have energy to perhaps have refrigeration for up to one month…maybe a bit more…but after that what?…I plan to be 100% quarantine with my whole family….we have made a pact that we are not going out. So once our gasoline runs out, our generator goes out of service. So I was thinking maybe I need to start buying things that need refrigeration in small cans instead of large containers…for example…mayonnaise….I figure buy small to be used up completely in that one meal…like one small can of mayo for two cans of tuna. Well, you get my drift, right?…but any ideas on alternative means of keeping things cold would be appreciated.

Thordawggy – at 21:47

There could be no way to keep things cold. So don’t rely on that. There are some things that will keep for awhile. Mayo is not one of them except in the small packets which is about 6 months. The small jars will have to be used up within a day or less. If you have some car or marine batteries and you keep them charged, you can use one of those cold/heat coolers with a 12 volt battery connection but they are only as good as the batteries last and they only cool within a certain ambient temp difference. If you have a basement and in a colder climate in the summer, the cement stays pretty cool for things like butter,margarine, cheese etc. if you keep them in a galvanized trash can directly on the cement. The trash can will absorb the cold to a certain point. Perhaps insulating the metal trash can on the sides and top only will help maintain the coolness. Mayo is an issue in our family too. A freind of mine makes her own mayo daily. I don’t have a recipe but I am sure you can find it on the net. It is like eggs and oil and seasonings. Italian dressing is a tasty subsitute. The dried packets with oil and vinegar. Two regular preps anyway.

Hillbilly Bill – at 21:58

My wife has a mini-fridge that she uses at work. I plan to bring it home when we quarantine. I’m hoping that we can keep condiments and such from spoiling by running a generator for short periods a few times each day. There definitely aren’t going to be any ice-cold beers…

montana99 – at 22:10

This may sound a little crazy, since I lived in Fla until a few years ago. I have moved to the Mtns of SW Virginia. We have a stream which runs in front of our cabin. Seems to me that even in the middle of summer the water is quite cold. Not sure about the exact temp, but maybe in the mid to low 50′s. Is that low enough to substitute as a refrig? If anybody knows for sure please let me know.

12 March 2006

IG – at 00:48

The last thing you want to do while quarantined and possibly without access to medical care is get sick from eating spoiled mayonnaise or cheese. In my estimation, the added flavor’s not worth the extra risk.

Prepping Gal – at 01:01

A few days ago we ate some cheese whiz from our pantry and then I read the expiry date june 2003. Tasted great & nobody got sick. I think that stuff would last years unopened. Refrigerated now that it’s open but it gave me the idea to buy more but I should have gone to small jars.

Eccles – at 01:32

One concept I have been playing with is the use of well water to provide some cooling. The aproximate groundwater temperature at my location is 52 degrees. Not exactly cold enough to truly be considered refirgeration, but perhaps enough for some purposes. Since we feed from a well, the water which is pumped out of the ground is rather cold to the touch right out of the tap. It should only require literally 2–3 minutes of generator operation to get a large amount of cold water to work with.

What I do with it and how is as yet being looked at.

For all of you fellow techno-Poindexters out there, I am also looking at using it as a heatsink for a thermo-electric cooler to see if I can beat the 4 amps required by the commercial car fridge.

Pfwag – at 05:43

Eccles - you might find these interesting:

http://www.i-m-d.com/engel/index.html

http://www.industrial-nanotech.com/index.html

http://www.fieldlines.com/story/2006/1/11/22240/6609

Your well water refrigerator is a heat pump. Check those MFRs.

BTW, what is it you do? You seem to know a lot of the stuff that it has taken me hours to discover or learn.

Fla_Medic – at 06:04

As a live aboard sailor in the tropics for many years, I’ve spent a lot of time without refrigeration. It can be done, with a few adjustments in life. <g>

A good article about living without a Fridge can be found here:

http://tinyurl.com/ppepf

Note: I’ve kept open Mayo for a week or 10 days without a problem. Just don’t contaminate the jar, always use a clean knife, and never go from the bread (or tuna <g>) back to the jar. Squeeze bottles of Mayo would probably be safer.

And of course, you can always load up with a pocket full of mayo packets every time you hit a fast food joint. <g>

DorienCTat 12:19

We always keep our opened mayo jar in the cupboard, for weeks!! In USA people keep so much more in the fridge than we do in other countries simply because your refrigerators are 5 times bigger!! Even in Brasil were we lived for a couple of years they just store it in the cupboard, even when temp. in the house is plus 90 degrees F. It is important that you never touch it with a dirty spoon or with your fingers. (So no licking out of the pot!) Interesting also: I once heard a comment from an executive in a large company that manufactures Mayo etc. that esp. in America they are VERY careful (read OVERLY careful) with exp. dates because of law suits. He also said that Americans have less of a problem with throwing things out when expired (so food companies can sell more). I can believe this. In Europe we are 2nd generation war survivors so a little mold on the cheese doesn’t stop us!

author – at 12:32

http://www.rolexawards.com/laureates/laureate-6-bah_abba.html

This site offers a possibility for cooling food storage without power. I’m not sure it would work everywhere, but it might be a solution for some.

anonymous – at 12:59

I am for the restaurant packages. I plan to get a box of condiment packages as one of my last min. prep items

Eccles – at 13:43

Confirmed that the water from the well is at 50F (10C) degrees. Interestingly enough, this is listed in some sources as the top temperature acceptable in some refrigeration processes. I would be happier with a couple degrees coolor, but starting at this point, it may be possible to start from here and come up with a way of storing food for a day or two until completely consumed.

As long as the well is operable, there ahould be many pounds of this heat sink water available per day.

Author - the double clay pot approach was discussed on the wikie a couple of months ago, and remains a fascinating option. I’m not sure how well it would work here in the States with humid summers, as it requires evaporation to make it work.

Of course, if I didn’t mind blowing my propane supply, I could achieve cryogenic temperatures simply by boiling off the propane.

Nanita – at 21:52

Wowwwwwwww!!!…thanks!…I didn’t think of restaraunt packages….anyone know if Cosco carries these?…and what about those small jelly restaurant containers?….Maybe I need to make a few breakfast visits to Dennys and The International House of Pancakes….thanks againnnnnnn.

Kim – at 22:06

Eccles, as handy as you are, I’m surprised you don’t build yourself a Crosley Icyball http://www.ggw.org/~cac/IcyBall/crosley_icyball.html

Fla_Medic – at 22:13

Nanita, try restaurant supply houses. You can buy the condiments by the case. I’ve done it when supply my sailboat for a long cruise.

A quick google finds this supplier of many condiments in single serve packaging (provided without recommendation)

http://tinyurl.com/rasqd

montana99 – at 22:18

My idea of storing perishables in water at approx 52 degrees is not acceptable according to what I have found out today. Most reputable sites reccommend low to mid 30 degree’s.

13 March 2006

Hillbilly Bill – at 08:38

Note to self - make a raid on the condiment section of all the fast food restaurants when BF goes H2H.

Eccles – at 08:47

Montana99 - Certainly for extended storage of foods, then you need a temp of around 40 degrees. But there is still a use for the 50 degree temps.

I did an interesting experiment yesterday in my fridge. I placed on of the little metal dial food thermometers into the fridge cabinet to see what temps are really occuring. Since our fridge is (a) 22 years old, and (b) loaded full, there was noticeable “zonation” of temperatures due to the poor circulation within the cabinet.

Up on the top shelf, the temps were cycling between 32 and 36 degrees. We have seen an occasional item freeze from time to time, but that is not usual. The interesting point was down on the very bottom shelf, right above the crisper drawers, (near the coils) the temp cycled between about 46 and 50 degrees. Also, the temps are higher in the front, by the door, than in the back, deep inside.

Since we always keep the really persihable and dangerous foods in the coldest sections, no problem. But now seeing the temps up near 50 at some spots, I real;ize that there have been times when we must have stored some foods at those temps, without getting food poisoning.

I think looking into how the colonists stored foods in crocks in the well or in a spring will be my next plan of action. SInce I can get 50–52 degrees with virtually no expenditure of fuel or power, I sure would like to see what I can do with it.

Eccles – at 08:59

Kim - the ammonia refrigeration cycle is well known, and is, in fact, used in a number of gas and propane powered refrigerators.

Sonce the contents of the contraption include a dangerous/toxic gas under extreme pressures, I have dismissed the idea a long time ago of doing anything along these lines. One cracked weld and you have a bigger problem on your hands than before.

But it is old fashioned technology like this that we have bypassedwith cheap and readily available electricity. here are probably other neat ways to get where we need to get.

And actually, since the Icy Ball and the propane driven refrigerators runn off of externally applied heat, then one ought to be able to run a similar cycle with solar power. I think that some specialty companies sell such things. they are just way off budget for folks like myself to contemplate purchasing.

Kim – at 09:38

Eccles, I would love to build an Icyball but I don’t have enough expertise to do so. I had contemplated, if I could ever con anyone into building one for me, using a solar concentrator (basically funnel-shaped mirrors) to achieve the heating portion of the cycle, but am afraid that might be too much heat, as the instructions says the heating must be gradual. Ah, well, I do have plans to use a solar concentrator (funnel) to try to build an in-ground cooling system, by using the funnel pointed at the night sky as a heat sink and aiming the funnel into a super-insulated in-ground “refrigerator” box (in-ground for extra insulation/cooling).

Eccles – at 10:08

Kim - My thoughts as well. Since you can run a fridge off of propane, it ought to be able to run off of the sun. There is one site I find from a company that says its gonna build them (I guess as soon as someone funds them).

The big problem is that the ammonia cycle is not a DIY kind of project, and there is no real demand for such a device FOR CHEAP in the developed world since we have all of the electricity that anyone could ask for.

The solar funnel as a cooling device is interesting, but I suspect that it won’t get things cold enough to make it through the next day until the next time you can see the night time sky. Also, just as in solar, a cloudy night will kill your source of energy.

You know, a long time ago, one of my profesors taught that if you ever find yourself saying “Whay doesn’t someone build a….”, maybe there is none, and you should be the guy to develop one for the world.

flourbug – at 10:36

The Icy Ball looks perfect for hot climates like Florida and Arizona.

Eccles – at 10:45

A modern version of the Icy Ball would be great for disaster sites and undeveloped nations. In other words, there is no money in it. But I sure would love to have one (working) in my hands right now. it would certainly solve alot of issues.

Kim - Just out of curiosity, have you considered the other solar concentrator project, a thermo-electric generator powered off of a solar concentrator?

Corky52 – at 10:52

http://www.builditsolar.com/Projects/Conservation/chest_fridge.pdf

Cheap and easy solar power capable reefer! You can get a 5 cubic foot chest type freezer for around $170, $30 for the controller and if you want to get fancy you can save even more power by adding a layer of extra insulation around and on top of the freezer! I’ve put 3 inches of hard foam all around, on top of and under my freezer. I’ll add the controller when I’ve emptied the frozen stuff out of it.

jon c – at 11:11

There is a fridge/freezer called a sundanzer and will run off less than 200watts of solar. they are a little pricy as about 1150.00 but they work great. we live off the grid and are saving for one.

Eccles – at 11:23

Corky52, jon c - I understand the availability of refers that run from a couple of hundred watts of solar panel. But that still represents an investment that is not possible for most.

The tantalizing thing about the ammonia cycle, and thermo-electric power is that they are a potentially much cheaper means of accomplishing the same goal. In my own case, I already own a 12v thermoelectric refrigerator that would require about 100 amp-hrs per day to operate. Thus, I should be able to get by with a 15–20 watt panel and a charge controller and battery. But that still represents too much engineering for the average Joe. beyond just myself, I would lke to figure out how EVERYONE can maintain some semblance of modern living till the grid gets back up and running.

In my location, the problem for about 4 months of the year would be to keep the groceries from freezing. its just the other 8 months I need to consider. But the folks in Arizona, or in Oz have a very much more difficult problem. I’d love to be able to use the sun against itself. And cheaply.

jon c – at 12:07

I live in Arizona and have a propane fridge now but the problem is the availability of propane. The sundanzer fridges only draw back is the price. I have concidered building an enexpensive ice house. A well isulated icehouse packed with large blocks of ice frozen in the winter may keep through the summer. This is all speculation though. The big problem with the 12v thermoelecric fridge is in hot dry conditions such as here they just can’t keep up with the heat. I tryed one last summer and it failed miserably. It was great to keep beer cold, but meat spoiled quickly.

Kim – at 12:21

Yes, Eccles, I’d love to build a Stirling engine powered by concentrated solar. My understanding is that that’s already being done on a commercial scale. I am mechanically inclined (no formal training in such) but absolutely terrible with math, so anything that requires math calculations (without some kind of clear, “just plug in the numbers” type formula) generally leaves my head spinning and eyes glazed over. Time and money always seem to work against me in all the projects I want to do (sound familiar, anyone???), but I really do hope to try out the solar-funnel in-ground icebox this spring and the solar-powered stirling engine this summer.

Eccles – at 12:34

Kim - The only issue I have with solar powering a Stirling engine is that the toy ones are to small to do anything useful, and building one sizeable enough to do real work requires some pretty fancy precision machining. You do machining by chance?

Kim – at 12:43

Eccles, I only WISH I was a machinist!!!! There is, however, a web-based business that will allow one to design their part(s) online, then they deliver the part(s) to you completely finished. I have the link to it somewhere, I’ll have to look for it (I think on my other computer), but have an errand I have to run now so will have to get back with you on that.

Kim – at 12:58

Ok, Eccles, I found the link to the on-line machining shop (had to hunt for it, it was driving me crazy!) http://www.emachineshop.com/

Eccles – at 13:06

Thanks! Coool!

Kim – at 13:19

I propose putting any great links on this subject that anyone may find at this spot on the fluwiki http://fluwikie.com/index.php?n=Brainstorming.ResilienceTechnology so everyone will be able to find them all in one spot

Michael Donnelly – at 13:31

I have just had 5 inches of snow dumped on my yard. I will be using my favorite tool (my Bobcat) to dig up a bunch of snow and pile it in my shed. Once covered with a bunch of loose cellulose insulation which I have, I figure it should last a few months. If power goes out and I need to keep some things cool, I can just use the show to keep a cooler or two cold.

Not sure how realistic that is for other people, but I just thought I’d share. Living in rural Wisconsin occasionally has its benefits :-)

Eccles – at 13:39

Michael - Some years ago I ran the calculations for a pit 10×10×10 into which I would Bobcat all the snow I could dump into it. If it has even modest side insultaion and good top insulation, it had the potential of providing substantial refrigeration resources for the entire warm season.

Of course, that was just a calculation exercise. Good luck doing something like the real thing. let me know how it works. if we’re still doing this next year, maybe I’ll get a backhoe in for a day and try it for real.

Corky52 – at 13:40

Eccles,

The link I posted and my own experience with a cheap chest freezer from Sears show that what you want is fairly easy to do. I have a propane reefer in the MH but after what I’ve found with using a freezer as a reefer I thinking of putting one of these units in the MH. Did you look at the article I posted? 100 watt hours per day, a 25 watt solar panel can easily handle that! My unit is not quite as good, I’m at 135 watt/hours per day, but I used a very cheap freezer.

The only drawback to this design is you need an 800 watt inverter to handle startup surge.

Thom – at 20:48

Corkey52,

Can you explain in a little more detail how you have your solar power capable reefer set up? I am looking at purchasing some type of solar panels, maybe even a ‘remote cabin’ setup that has the panels, wire, charge controller, batteries, etc but would like very much to have whatever guidance you would like to share. The building / configure a freezer into a fridge using just solar is one goal of many.

Aside form the (Sears) freezer what kind of controller would I need and is there any thing else?

Thanks much in advance.

Thom – at 20:49

PS - I have both an 800 and 1200 watt inverter already.

Corky52 – at 23:02

Thom,

The link in my 10:52 post is to an article on how to convert a cheap chest type freeze to a low power consumption reefer. In my case I used an even cheaper/smaller 5 cubic foot chest freezer from Sears. All you you really do is set the freezer to freeze and then add an external temperature sensor to control the power to keep the temperature in the reefer range instead.

I did add more insulation around the exterior of the freezer and to the top and bottom, being sure to leave air flow for the coils. The insulation I used was the rigid foam sheets from Home Depot, get the metal foil backed if you can, but the plain foam is nearly as good. I cut the foam to size with a knife and used duct tape to build a box around the sides of the freezer, cutting holes for the air vents of the compressor. I then cut a piece to size for the top, used duct tape a a hinge, not pretty but functional. I also did a piece for the bottom, cutting out squares for wood inserts to support the feet of the freezer. I think the foam on the bottom is over kill and wouldn’t do it again.

My unit in reefer mode consumes about 135 watt/hours per day including the losses from the inverter. If you get 6 hours of good sunlight a day on a 45 watt panel you’ll return enough to the battery to run the reefer. I had a temp controller around, but it was an old one, so I’ll have to find a link to something on the net you can use.

The article touches on why the chest is some much more efficient, cold air doesn’t “fall out’ of the chest every time you open the door, and have to be totally replace.

Corky52 – at 23:49

Thom,

This is a newer version of the controller I’m using.

http://www.herpsupplies.com/product.cfm?id=ETC111000

14 March 2006

Corky52 – at 00:13

Thom,

Be careful opening the box if you order from the place I linked to! ;-)

Eccles – at 00:18

Corky52 - I did indeed see the article you posted. I have stuck it in the back of my head. I’ll probably build one next winter if this nastiness still ahsn’t hit. (It’s too late for this summer, given my budget, and around here, once winter sets in, cold storage is not a big issue).

Again, the drawback is the need for (and expense of) a 45 watt panel, charge controller and battery. This is the most direct approach.

Being the techno-geek type, I’m still looking to take advantage of other applications of physics. Not just for me, but for a more general applicability. Now, if someone still made a reasonably priced version of the Icy-Ball, search is over.

Corky52 – at 00:26

Energy source is always the problem! Power to the people is not an empty statement! Energy density is the best measure of the level of a civilization.

You need panel and battery, charge controller while nice is an absoulute, just have to check the water every couple of days. What else you going to have to do if AF hits?

Corky52 – at 00:28

Charge controller is NOT an absoulute! Sorry about the lousy typing!

countrycanuck – at 01:44

if concerned about refrigeration, be sure to also read the posting titled “ice houses”

Thom – at 06:11

Corky52 - Thanks much, I will start puting this together as soon as I gather the parts and pieces.

Hillbilly Bill – at 08:12

Corky52 and Eccles - for those of us who are solar challenged, how much would this drain a battery bank setup each day?

I have a working chest freezer that I am not using. I thought about also making a rim around the inside a few inches down from the top and cutting foam panels to fit. This way, when you open the lid, less energy is lost. With some pull rings on the panels, you could open up just the section you needed to get to.

Hillbilly Bill – at 14:46

anybody?…..anybody?…..Buehler?

flourbug – at 15:47

Well, I’m talking about something I know nothing about here… but what about an ice maker hooked up to a solar panel? The small portable models are advertised to make 12 ice cubes in 10 minutes, or 35 lbs of ice per 24 hours, on 200W.

Carrey – at 16:16

flourbug Now those things are interesting! I’ve never seen anything like that before. Anyone know what a solor panal/battery ect would cost to run that baby?

Carrey – at 16:17

http://tinyurl.com/s5v3l Heres what I found online, they are so cool!

Fla_Medic – at 16:34

Hi flourbug, perhaps I can help with this.

I googled, and found an ice maker called the Portable Ice Maker by SPT USA. Thinking this might be the one you are looking at. <g>

The specs are 115 Volts / 60 Hertz, 200 Watts, 3.48 Amps

A typical 50 watt solar panel produces about 16.7 volts and roughly 3 amps. Prices for one panel of this size run $250-$300.

Unfortunantly, amps @ 16.7 volts do not equal amps at 115 volts. You’d need more than 15 solar panels to provide enough power to run this unit.

To make this work, you’d need a sizeable battery bank, an inverter (converts 12v to 115 v), and a large array of solar panels.

In other words, a solar panel of this size would feed about 3 amps into a battery bank (optimal) each hour, while the ice maker would draw out about 35 amps each hour. A fully charged 100 amp battery would be dead in a couple of hours.

This is the not-so-cold equation cruising sailors have lived with for years. It’s why most of us get used to warm beer. <g>

Hope this helps.

flourbug – at 16:59

Hope this helps? *sob* Noooo.. it didn’t help at all!

Eccles – at 16:59

Flourbug, Carrey - 200W is ALOT of power to supply to a continuous load using solar panels. As Fla_Medic points out, it would take a fairly sizeable array to run the ice maker. But you don’t want to make ice anyway. Ice is essentially a way of storing “cold” in a compact form. It absorbs huge amounts of heat to melt ice, and so you must remove huge amounts of heat from water to freeze it. If all you are looking for is refrigeration, then you can either buy one of the Thermo-electric refirgerators sold by the same guys Fla_medic found the ice makers at, our else you could do what Carey52 is doing to make a highly efficient chest refrigerator out of a small freezer. In the case of Carey52′s device, you would be able to get away with about 1/20th the energy consumed by the ice maker. A thermoe-electric refrigerator would need about 1/4 the energy of the ice maker.

Hillbilly Bill - Well, EXCUUUUUSE me. ;-) I have a life too you know. Anyhow, the chest refrigerator would need between 100–150 watt hours per day. This means like 110–165 watt hours or 9–14 amp-hours from your battery per day. A 45–50 watt solar panel would give you just about that much ± of recovered charge. Since you don’t want to overtax the battery, you would probably want a minimum of a 60 amp-hr battery to run things. If you want coverage for a couple of cloudy days, then you are in trouble. You would need a bigger battery and a bigger solar array to make up for the power consumed on days when you don’t get sun.

Fla_Medic – at 17:04

Sorry Flourbug, I’ve had to deliver `the bad news’ to a lot of people in my career. It’s never easy. Sorry it had to be you this time. :(

hvac – at 17:53

did any of you think about……co2? you can get it in 30# tanks (or larger) at resturant supply houses or gas distributers. you need to specify the tanks with siphon tubes. this brings the liquid out of the tank. you need a containment jacket, (something closed like an arm cuff with a tiny hole in it to prevent excessive pressure buildup) a hose attached to the jacket (with the other end connected to the tank)…open the tank valve, let the liquid flow into the jacket and you can make dry ice. the charactistics of the container (cooler) size and thermal capabilities will dictate a six or twelve pack. must warn you need protective gloves when handling this setup.

hvac – at 18:05

oh just a tip…when the solid starts to form you have to break it up and massage it to the other parts of the bag otherwise it will collect at the inlet of the dicharge of the tube and slow the gereration process. this is why you need the gloves. and beer was just a suggestion……you might have closed medicine that once opened will require refrig until consumption is completed.

Kim – at 18:36

hvac, could you expound a bit on using CO2 to make dry ice (for someone like me who is technologically challenged in this area)? You speak of a containment jacket (something like an arm cuff). When you say this, the only thing that comes to my mind is a blood pressure cuff, is this what you’re talking about? If not, please explain what an arm cuff is and where I can find one. Also, how do you know how much liquid to let into the cuff? Sounds like an easy way to make dry ice but I hope you can explain it to me a little better. Also, are there any safety issues we should be aware of in storing and using CO2 tanks (other than wearing gloves to protect against cold)? Sorry for what may be dumb questions. Thanks!

hvac – at 18:54

the arm cuff was just a visual to get the idea across. it could be any material strong enough to resist tearing and extreme temperature changes. so that leads to flexible type materials. blue jeans? you can sew something that will contain the liquid as is comes out. the material willl be porus enough to eliminate pressure buildup and allow for the liquid to accumulate and mass up as dry ice. the hose can be gotten from the tank suppliers and the connector to the cuff can be fastened with nuts and washers that fit the hose end. yes it is easy as long as you dont touch it directly. the pulsing of the valve will allow for intervals to break up the chuncks. i mean 25 sec on 10 sec off. the tanks are burst pressure certified and dont post a problem for storage or transport. they have pipe freezing kits that incorporate this idea and utalize the cuff concept. i am just thinking one step beyond. there are many companies that sell these kits. but the concept is more adaptable. i am unsure of the deposit required for the tanks its about ten times the value of the product inside.. got any friends in food service?

hvac – at 18:56

the cuff has to be like a innertube

hvac – at 18:58

intertube

Kim – at 19:06

Thanks for the info, hvac. I googled co2 tanks, one of the first sites I came to sells a new, empty 20# tank for almost $140!!! I may check around locally to see what kind of pricing I can get at a restaurant supply place, it would be nice to have the means to make dry ice as an alternative cooling source.

hvac – at 19:19

the source (20# tanks)and liquid requirement for chunks of ice is not that reliable for long term solutions….as the gas changes state it deminishes back into vapor….that means no more cooling effect or obviously ice…..so this can again only be useful for beer and or medicine not food. i have sucessfully sustained a block of ice using a 20# tank for three hours until the tank depleted itself (the block remained for another three or so hours.) remember conditions at point of use will determine the results. that seems high for the tank price is that for the purchase or the rental? most companies rent them and the deposit is only to ensure their return.

Busy in Bama – at 21:05

I have a stable I converted into a small guest-house,when the Old Grey Mare went to horsey heaven. Propane heat,HW heater,& stove. If I could get a propane frig,I would have a little “Propane Palace”---Power outages welcomed. Called several LP dealers—no luck. One said there is such an animal, but he thought AC was still required for some kind of Fan. —how bout the little man that turns on the light when you open the Door?—un-employed?---seriously tho, anyone know of a product or link? thanks

Busy in Bama – at 21:06

I have a stable I converted into a small guest-house,when the Old Grey Mare went to horsey heaven. Propane heat,HW heater,& stove. If I could get a propane frig,I would have a little “Propane Palace”---Power outages welcomed. Called several LP dealers—no luck. One said there is such an animal, but he thought AC was still required for some kind of Fan. —how bout the little man that turns on the light when you open the Door?—un-employed?---seriously tho, anyone know of a product or link? thanks

Corky52 – at 22:15

Bama, RV’s have propane frezzer/refigerators, so check RV supply houses. RV refeers do need a small amount of 12vdc to run the controller!

Busy in Bama – at 22:24

Thanks Corky52--I’ll try that

Eccles – at 23:02

Corky52 - Sorry about calling you carey52 up above. You know us oldztimers syndrome sufferers.

15 March 2006

Carrey – at 09:00

Eccles, Corky52?

So now that my hopes are dashed about the portable ice maker :-) Would either of you be able to explain to a non-engineer type the idea in the chest fridge? And also is this something that could be run on solar panals without us going broke? What about a normal chest freezer, could it be kept frozen using solar reasonably?

Corky52 – at 09:32

Carrey,

Chest freezer is used because no chest reefers seem to be available. Chest is more efficient because it doesn’t let all the cold air fallout when you open the door. Idea is fairly simple, use the extra controller to keep the chest area at reefer temperatures rather than freezer temperatures without a huge amount of mechanical work. Freezer controller is always in on position because it wants to see colder temps and the external controller turns the cooling unit off and on to keep temps in reefer range.

You might be able to run freezer on solar, it will just take more power as you will be running it more. I haven’t looked at how much power it would need, may try in the next few days. Big power cost is starting motor of the compressor, and that would be the same for reefer or freezer, you’d just have longer run times.

Now I have a dumb question for anybody that knows, can you freeze things to cold? One way to up the efficiency of the freezer would be to get things really cold once you start the compressor motor and not restart the motor till the temperature was quite a ways back up. Just starting the motor eats as much power as running the motor for quite a while.

Eccles – at 09:46

Corky52 - Its really a question of maintaining temperature once it is achieved. The actual freezing process will consume a fairly large amount of power as you need to remove the heat of crystallization from the water to turn it to ice. Once things have been frozen, then the energy consumption is countering the leakage through the insulation. Thus maintaining a temperature is the process of balancing the flow of external heat into the cabinet.

The larger the thermal contrast to the outside, the more energy you will need to spend in removing the heat leaking in through the walls (think of it as the heat being under higher “pressure” relative to the contents of the box). So the colder you make the contents of the freezer, the more energy you will spend in removing heat which leaks in through the walls. that’s why the chest reefer setup is so efficient. The freezer is better insulated than a normal reefer, and so the leakage at reefer temps is quite low. Once you start reducing the temp inside the box, then you need more and more compressor time.

Once everything is frozen, it is a one-time effort to make it colder, but then you pay the “rent” on that temperature forever after.

Hillbilly Bill – at 09:47

Corky52 - So what you are saying is to build in a bigger lag between when the compressor turns on and turns off. Interesting idea! How do you get the thermostat to do that?

My project for the next few days is to do some experimenting with the chest freezer that I have. Currently I have the bottom of it full of two liter soda bottles 85% full of water. My plan is to turn it on if we have to quarantine. The frozen bottles of water will give me a few more days to use up perishables if the power grid goes down.

Since we plan to run our generator a few times each day, and for a 3 hour stretch every other day or so, I want to see if I can keep those bottles of water fairly well frozen. If so, then I can use these frozen bottles to keep perishables cold in my cooler. More than likely I will need to add some insulation to the freezer.

Eccles – at 09:52

Bill - Increasing the lag on the thermostat is easy. Since Corky is adding an electronic controller outside of the stupid thermostat loop used in the freezer, you can just design one with a larger “dead zone” between turn-on and turn-off. trust me, it is a very simple design feature, as you would normally add some hysteresis to a thermostat anyway to keep it from turning on the compressor too often when things are right “on cusp”.

As Corky points out, it is very “expensive” to keep starting the compressor, so you would design the thermostat to wait until things got kind of warm (say about 46 degrees), and then run till things cooled of by like about 10 degrees. Not necessarily the best for very long term food storage, but for austere conditions, it should do just fine.

Carrey – at 09:54

So would it be feasable to run the chest fridge on solar? Or would it take a whole roof full of panals? Please forgive me for sounding like an idiot! :-)

Hillbilly Bill – at 09:56

I understand how this is done on a mechanical thermostat like the one on my wood furnace, but didn’t realize it was easy to do with an electronic one.

Corky52 – at 09:59

Eccels,

Your right on the theory and missing the engineering! Motor startup is the culprit that is stealing the most power, the fewer times a day you can do it the way lower your spike energy needs. Better insulation is one side of the equation but also using the running motor as much as possible while it’s on, hence the question if food can be frozen too cold. Temperature rise/fall and energy usage are linear functions once motor is running. Renting the extra cold may be energy cheap compared to start costs.

Bill look at the controller I linked to earlier in the thread, you can adjust the set points for off and on, have to use one like that to replace stock controller in freezer. I’m not sure the one I posted has temperature range needed, have to check on it.

Eccles – at 10:08

Corky - It will be easy to construct an equation that takes into account both the energy consumed by the motor startups and the “excess” losses due to colder temperatures and come up with an optimal solution that would accomodate both issues.

Since this is a refrigerator, we are limited by the requirement not to freeze the contents of the box. If we could fractionate the compartment so that the lower bay was frozen and contained ice, and the upper was “cold stuff” but not frozen, we might actually be able to cost for hours or tens of hours after a very long run. That might capture the efficiency advantages you are seeking with the long compressor run times.

Corky52 – at 10:09

So the controller will go to −30F and has 30F max range, looks like it might work. My problem is I no little about food and how it would be effected by temperature swings at this level. Any cooks out there have any ideas?

Corky52 – at 10:13

Need more coffee!!!!!!!!!!!!!!!!

change no to know and effected affected!

Eccles – at 10:19

Corky52 - Gotta run along for the day, but basically, there are many foods that will change characteristics if they freeze then unfreeze. Thus, frozen stuff should remain frozen and unfrozen stuff should remain cold but unfrozen. Anything else will make for unhappy foods.

Corky52 – at 10:20

Ecceles,

I was thinking in freezer mode, in reefer mode a 15F seems to work well on my current unit. I have it setup to monitor the current to the inverter both peak and 24hr total usage, also keeping track of inside and outside temps. I’d love to move the compressor and coils out of the box, but that’s to much work for most people and so I haven’t done it yet. I’m trying to stay with what most people could do.

Kim – at 12:35

Corky52, if your temperature range is −30 deg F to +30 deg F, all should be well with your food. A temp of −30 deg F won’t hurt anything, and up to +30 deg F will still keep it frozen. Just make sure, as Eccles pointed out, not to let the temp get above +32 deg F, or you’ll end up with a mess.

hvac – at 18:30

i am not a physicist but there is a threshold somewhere between the offset in temperature (swing range) and the recovery run time. this will make the large offset you are thinking of impractical. to many variables to calculate without in depth calcs. my off the cuff answer would be to maintain a range no greater than 15 degrees. this will increase start-up current and deminishing the end target results but in addition any attempt will surely help. (my suggestion would be to reduce the low end of the scale,[reducing the delta T ]) find out the safest warmest temp for frozen items you want to keep and swing backwards from there

Kim – at 18:43

Corky52, the ideal temp for long-term storage of frozen food is zero deg F or below (which is why I keep food that I want to store for awhile in my chest freezer). For short-term frozen storage, anything from zero deg F to 32 deg F is acceptable (which is why I keep anything I’ll be using soon in the freezer portion of my fridge… it doesn’t stay as cold as the chest freezer)). Hope this will help you with your calculations.

hvac – at 18:53

could you burry the chest to flush with ground level and reduce the thermal transfer to the surounding environment?

16 March 2006

Eccles – at 00:19

hvac - the problem with burial is that the chest is still a residential chest freezer. The coils will need to communicate with ambient air or the whole thing will be unable to shed the heat produced by the compressor plus that heat extracted from the cabinet. Corky52 and HillBilly Bill have the right idea by adding additional insulation to reduce the rate of heat flow into the box.

Corky52 – at 05:39

I tried something last night, put a small fan pulling air out of the area where the coils are. Early results look pretty impressive, seems to cool down faster. I’m thinking of using a couple of computer fans, run off of a wall wart plugged into the the main power feed and see how this works long term.

Eccles – at 07:33

Corky52 - I am assuming that you are using these on the coils on the outside of the case. That would certainly increase the cooling efficiency and might reduce the total power required for cooling noticeably.

I was also considering whether using a fan insde the reefer would also help. Since the box is in a vertical format, the cold would tend to stratify, with the coldest at the bottom (naturally). This would then lead to the stuff near the top getting warm while the stuff at the bottom is still very cold/frozen. Again, moving some air around inside the reefer might make the coasting period between compressor runs even longer (i.e fewer compressor starts).

Of course, in a battery dependent situation, one would need to watch the p0ower consumption of the fans as well. they might reduce the consumption of the reefer, but add back the same or more power consumption.

Corky52 – at 11:40

http://www.campingworld.com/browse/skus/index.cfm?deptID=&skunum=6675&src=FPC

Use these in all our reefers and freezers, keeps temperatures very even.

Eccles – at 12:01

Really cool. (No pun intended, but applicable).

I might just pick some of these up as well. Given the run time on a set of batts., these could be handy for many applications.

hvac – at 19:12

eccles 00:19

i understand the need for air movement and assumed the obvious.(that this condition must be considered.) therefore i offer two solutions. vent stacks one as an inlet the other as an outlet. the size would have to be reflective of the fan cfm and the surface of the coil. three feet or so wont offer much static resistance. the insulation is a good step but the ground temp is better (or more stable from outside influences). i have something even better for the more ambitious….remote locate the condenser and compressor. it will allow for service should you need it..the other way you would have to abandon the chest…..heck do both bury it with insulation around it…….this is craaaaaaazy but im glad were kicking it around

love the ideas about internal fans, effective? maybe never tried it why not move the sensor to the middle or the bottom? the temperature layers inside cant be that far apart

anonymous – at 19:34

test

17 March 2006

Corky52 – at 02:31

hvac,

Your ideas are good, just beyond what most people could do. Where I live you need a jack hammer to get down two feet, SoCal is like that. If I lived in an area where it was possible I’d have a root cellar and put reefer/freezer in it. I try to stay with modifications that just about anybody can do with simple tools and as little cost as possible.

hvac – at 16:02

if you cant lower the river raise the bridge….if you cant dig down then surround the freezer above ground with dirt. (just another out of the box idea) i admit there are some specialized tools that one would need to pull something like this off….but the point of the excercise is to generate discussion and inplement a doable plan with avaliable resources. if you have insulation and no friends in refrigeration then thats what you do

Hillbilly Bill – at 21:17

It seems to me to be much easier to glue or duct tape some Celotex insulation on the sides and top of the chest freezer rather than burying it in dirt.

flourbug – at 21:26

I bought a porcelain water dispenser that claimed to keep water 12 - 15 degrees cooler than ambient air temperature. HA! I now have a big jar of warm water on my counter. Even worse, when I fill it with refrigerator chilled water, the condensation drips onto my counter then flows onto the floor in a big puddle. Looks pretty, works not.

Kim – at 21:37

flourbug, if it’s made of glazed porcelain (glazed is very shiny, looks almost painted) then it is NOT designed to cool water. Only an unglazed ceramic can cool your water, through evaporation as the water very slowly seeps through the open pores of the ceramic. I’d ask for a refund.

Kim – at 21:43

flourbug, what you are looking for is a terra cotta water cooler, just google it.

flourbug – at 21:50

Kim, its glazed inside and out. There was a substantial amound of condensation on the container, in fact at least a quart flooded the floor by next morning. I repositioned it so it sits on rubber dish drain mat that will direct the water into the sink, but its not condensing any more. If unglazed ceramic seeps any more than porcelain there wouldn’t be anything left to drink! lol I have a serving thermos that will keep 2 liters of water cold for several days, and wanted a nice, no-tech version of my friendly kitchen water cooler. Instead, I think its going to be relegated to the isle of rarely used party supplies. Now, if I can only convince Aladdin to make a 5 gallon insulated water dispenser…

Kim – at 21:54

flourbug, look at Ace Hdw, TrueValue Hdw, probably even Walmart… they have large (up to maybe 15 gallons or so???) insulated jugs with spigots. Alot of construction crews use them in the summertime for their workers.

flourbug – at 21:56

Kim, I will do that! Thanks for the info. :)

Urdar- NO – at 21:59

one way to keep the food in the deep-free, (and the fridge) in a short blackout is “freeze elements” you make them your self by putting bottles or larger plastic cans that is of the tough type in the deep freezer. In the bottles you put salted water almost complete full. The salt amount i don know, but something similar like sea-water should be fine. The salt lowers the freezing point of the water, and it will suck the heat from its surroundings, keeping the deep freezer colder for a longer period. This elements may also be moved over to the refrigerator in a blackout. The larger aomount of this the better, but it will give you lesser space for food..

18 March 2006

Hillbilly Bill – at 09:08

bumped to keep this discussion going.

I plan to work on adding insulation to my chest freezer today. Then I will be ready for a test run to see how long the freezer has to run to keep bottles of water frozen or nearly frozen. I know from experience that two of these in our cooler will keep condiments and leftovers cold enough for at least a day. I will record temperatures and post to this thread when experiments are finished.

Eccles – at 11:13

Bill - I am doing a similar ‘speriment, but in a different directon.

Here’s the deal: This week I defrosted the small refrigerator that we keep downstairs for overflow and condiments and stuff like that. I originally wanted to use its freezer to treat bags of grain prior to deep storage, but found, to my dismay, that we hadn’t actually defrosted it in years, and the freezer was virtually filled solid with ice. So I took the contents of the reefer and piled it all neatly into a Bankers box, which it nicely filled, including about 8 1qt packages of UHT milk. (Keeping them in fridge insures long storage and good taste). Just for grins, I also stuck a food thermometer down in between the milk packages with the dial visible at the top of the box and put the lid on. Now, remember, this box is only thin cardboard, and has holes for hand grips in the sides.

Well, the job took 14 hours to melt that demon ice out of there. In the meantime, the contents of the Banker box only slowly rose in temperature until after 14 hours things were still only at 52.

Got me to thinking about what kind of hang time one could get with thermal mass, but no phase change (cold water, no ice). Especially since I have already found an unlimited supply of 52 degree water.

So here’s the experiment - Use a thermoelectric car cooler the chill down say a gallon of thermal mass that was already at 52 degrees, and then put it into a thick-walled styrofoam chest (used to ship medicine) and then see how well it stays cold. By also measuring hot water in the same situation, I can develop an external temperature vs hold-time curve. Then it is just a matter of minimizing the run-time of the thermoelectric refrigerator to conserve batteries.

My hope is to be able to hold a volume of about a 6-pack at a temp below 46 degrees at an ambient in the high 70′s for at least 24 hours. And do this with an expenditure of less than 25 watt hours.

I’ll let y’all know how things are going.

Hillbilly Bill – at 13:08

Eccles - Just stopped for a lunch break and saw your post. Looks like we both have our tinkering caps on today. My chest freezer is a 20 cubic ft model, and it is at least 30 years old, so if I can get this to work for me, then it should work for anybody. The seal on the lid is the most vulnerable part of my freezer so that is why I am adding extra insulation inside. Also I will be cutting off about 4 cu ft of space that needs cooled. I am cutting 1″ x 2″ wood strips and gluing them on the inside about 6″ down from the top. These will hold the foam panels in place. I have about 3 dozen two liter soda bottles 85% full of water ready to go into the freezer. Spaced out, they will cover the bottom of the freezer. My hypothesis is that once you have something frozen, you can keep it that way with a minimal expenditure of energy. Since I will plug in the freezer when/if we have to quarantine, I know I will be starting out with the bottles frozen when/if the electric grid goes down.

Good luck with your experiment, hopefully we will both come up with solutions that can help our fellow wikians.

Eccles – at 13:14

Bill - From an engineering standpoint, once you have the bottles frozen, then you require the energy needed to remove the heat which leaks in from all sources, whether it be through the sides or when the lid is opened. By adding extra insulation, you address one of the two energy consumption issues, which is rate of heat flow through the insulation. The other issue is the heat removal efficiency, which is a product of the compressor unit and its state of repair.

We’re really both looking after the same answer, just in different methodologies. In my case, the thermoelectric refrigerators that are designed for cars and camping assume that there will be constant power. they don’t do a really good job of maintainng the cold once power is removed. In fact the thermoelectric cell is one area of significant heat leakage in the absence of power.

Lets see what we both find so we can get these nice folks some cold alternatives when needed.

Corky52 – at 13:22
clark – at 14:30

All you need to keep a freezer going is pump the gases aound. You could hook up a stationary bicycle with a belt to the pump and do it yourself. Also a little petrol/gas motor to the freon pump- or a wind mill, water wheel. Converting energy to electricity and then using electricity to run a motor- is great when you have other things to do- but is enourmously inefficient otherwise. Washing machines are the same- if you could get an old agitator-whinger machine.- hook it up to a gas motor. Electricity is best for things like light, computers, stereos and TV. Cooking heating and motors can be achieved more directly- wood fires, muscles and gas motors.

I am not an engineer so I can’t provide the detaails.

Corky52 – at 14:38

Clark,

Electricity is fairly simple to generate and use, also most of the readily available equipment is designed to use electricity, so why fight an up hill battle. My solar requires neither fuel nor work to capture energy, doesn’t make noise and attract attention. Trade offs are part of the game, time and work for greater efficiency might be worth it if other fuels weren’t also required.

hvac – at 14:40

clark 14:30

the pumps in freezers are hermedically sealed motors. they also require steady and precise pressures to generate the refrigeration cycle. there were some belt driven low rpm compressors but most have evaporated over time.

hill bill 21:17

it was just an idea

Hillbilly Bill – at 16:26

hvac - no offense meant, all ideas are welcome! By cooperation I feel we will solve these problems.

Torange – at 16:28

A simple way to add insulation is to build a box around the freezer and use cans of spray foam.

hvac – at 16:35

hill bill 16:26

none taken.

Hillbilly Bill – at 16:37

I have the wooden strips in place and I will let them get nice and set overnight before I add the insulation panels and start the freezer. If I don’t get the results I am looking for, I will try adding celotex panels to the outside of the freezer. As I said before, this freezer has a lot of hours on it. If I can get it to do what I want, others with newer models should do even better.

Torange - Interesting. I just love squirting cans of “Great Stuff”!

hvac – at 16:44

Hillbilly Bill

can i add one thing? an air space has thermal qualities. it can act as a break in the transfer process. either inward or outward. maybe not fill in between the furring strips?

Hillbilly Bill – at 16:55

I’m going to put a layer of 1″ foam about 6″ down inside the freezer. This will leave an air space above the foam layer and the lid of the freezer. I know the seal around the lid on this freezer is not in the best shape so this should help a lot.

20 March 2006

Hillbilly Bill – at 09:58

I picked up a pack of foam panels at Lowes and installed them in the freezer. The panels are 3/4″ thick so I put in two layers. I chose these over a sheet of celotex because they are easy to work with and I could transport them home in my car. I used a small sabre saw to cut the panels to size because it produces a smooth edge, but if you are patient, you can achieve the same result with an exacto knife. I turned the thermostat on the freezer all the way up and plugged it in about 3:00 p.m. I checked it before going to bed and then again this morning. The compressor was still running this morning and the bottles are not frozen solid, but they are getting close. I’m sure the temperature will be stabilized by this evening and I will start the test to see just how little I have to run the freezer to keep the bottles frozen.

Eccles – at 10:49

Bill - The results of my experiment were a little disappointing. I placed 4.5 pounds of contained liquid thermal mass at a start temp of 36 degrees into a medical shipping styrofoam container and lidded it. I opened to check every couple of hours. What I found was a consistent temperature rise of about 1.5 degrees per hour until it apporached the room temp of 67 degrees, when, as one would expect, the rate of warming slowed down.

From this measurement, I can at least derive the rate of heat loss and determine just how much heat needs to be removed per day to keep things broken even. This works out to a loss rate of about 7 BTU per hour, which is more than I wanted to see.

In this experiment, things warmed up to 50 degrees, my cutoff point for having to do something about it, in about 10 hours. I was hoping for 24. Either I need more thermal mass or else I need to look at some of the 5 degree C phase change blocks available for shipping meds. The problem with them is they still need to be frozen at 0 C to activate them.

Hillbilly Bill – at 11:15

Eccles - None of this is easy is it? Of course if it was, we would all have different looking appliances for cooling in our homes.

I was somewhat surprised that the water bottles in my freezer were not frozen solid after it had been running 15 hours. Hopefully, it will also take them a long time to thaw out when it is not running.

My plan of adding more insulation to the sides of the freezer will not work. It seems my model “dispenses” heat through the sides to cool the interior. It may be possible to put a layer on the lid, although how effective this will be with the other insulation inside is in question.

Another concern is whether two or three frozen bottles will keep the interior of my cooler cold enough to prevent food spoilage. It is a new one, and ice melts slowly in it so maybe all will be fine.

I’ll post results as they become available.

Eccles – at 11:27

Bill - You should get one of those little dial thermometers that food inspectors use. That’s what I am using. hey respond quickly, can be poked into spots between things, and you can just leave it in a freezer/reefer if you want.

Depending on the stratification of temperatures, as long as ice is present, you should be OK. Determining how long a known quantity of ice lasts will allow you to determine the rate of thermal leakage to a first order. The time it takes to refreeze those ice bottles should give you a measure of the rate of heat extraction, and when you determine the electrical consumption, that should give you a measurement of thermal efficiency of the freezer with regard to power.

No if I could only find a phase change material for 45 degrees F that freezes at 36 F or above, I’ll be happier than a ……..(fill in appropriate countrified expression here)

Hillbilly Bill – at 12:08

Eccles - A plethora of countrified expressions came to mind, however none of them are appropriate to post here ;)

Eccles – at 12:51

Another result, kind of fascinating in fact…

The Seebeck effect has been known for nearly 200 years, in which two dissimilar metals in contact with each other generate a voltage. This is how a thermocouple works. it turns out that a Peltier junction (the thermoelectric cooler unit found in solid state refrigerators) will exhibit the Seebeck effect as well. (I never knew that in all the years I used TE coolers).

Anyhow, having run into this on the web, I ran right out to my work shop and got a 1″ square TE cell and measured it as I placed it in the palm of my hand. The workshop is at about 40 degrees, and so was the TE cell. It immediately started cranking out 175 millivolts at 15 milliamps, with the voltage being proportional to pressure into my hand (heat source). This lasted for 15–20 seconds until the temperatures equalized across the TE cell.

Not alot of power, but also not alot of heat and sinking. I intend to pursue this. I know that’s how they build the nuclear batteries for deep space missions. Maybe we can build a couple of watts charger running off of a charcoal briquet.

Just a thought. Siezure over. move along. nothing more to see here.

Hillbilly Bill – at 13:11

I can easily visualize it now, the wood pellet refrigerator! A mini wood-pellet stove provides the energy to keep your perishables cold and also serves as a hand warmer and conversation piece. Just a cup of hardwood pellets is all it takes to run this efficent little marvel for a full 24 hours. Act now! Don’t be the last family in your neighborhood to have one.

Corky52 – at 13:25

Why not just build a steam powered freezer, less R&D and much more feasible. Parts and gear would be off the shelf, just not cheap.

Eccles – at 13:31

Bill - Actually, that’s not far from the idea.

Corky52 - Don’t you get it? I’m an electronics/optics/radiation kind of guy. You’re a plumbing/moving parts/pistons and rotors kind of guy. I’ll leave the steam powered stuff to you, I’m trying to do it the good old fashioned Star Trek way. :-)

Corky52 – at 13:47

Eccles,

Actually I’m just lazy and pragmatic! Once the food supply is assured I’ll then take time to theorize and experiment, “eat first, then think”!

Hillbilly Bill – at 14:04

It’s not a challenge unless you incorporate antimatter and a photon generator…

hvac – at 17:31

eccles 11:27

phase change material……or change state liquids? the liquids are avaliable and the mechanisms are more readily adaptable for dispersal and recovery by a piston/rotor type of guy. are you of the thought that heat removal from a refrig can power your te cells and put the cycle into a loop? you cannot absorb heat from the te cells unless you are in an environment less than the target setpoint. electricaly based pursuit in my opinion cannot be a remover of heat since electron movement is a source not a conveyor. i do like the idea that body heat can generate electricity. how about multi metal coated fabric long johns?

hill bill 11:15

i would go after as much lining of the interior as i could with the sacrifice to food storage ratio kept in mind. i say this because the heat travels both directions (if the coils are concealed in the shell). most likely more inward that outward. how about taking the skin off of the exterior and letting the heat get out with increased circulation? if the refrig is utalizing the shell (with the evap coils conceled in the skin) this would seem to be the thing to do. warning! without a mfgs schematic you are playing rulet with the hidden coils.

Kim – at 17:46

Hillbilly Bill, check out a wood burning refrigerator, an even greater improvement on it would be one that burns wood pellets

link

hvac – at 17:59

problem…..liquid ammonia

Hillbilly Bill – at 20:32

Kim - Ahhh..Mother Earth News..that brings back memories. I remember when I was going to quit my job, drop off the grid and make a living raising rabbits and selling earthworms.

Hillbilly Bill – at 20:36

Project update - Freezer was still running when I got home. Yikes!! 27 hours straight!! I turned the thermostat back to the normal setting in hopes that it would soon shut off. Thermometer registers 22 degrees and water bottles are not frozen solid, but getting close. I will let it run tonight, record temps when I go to bed and get up and unplug when I go to work tomorrow.

Kim – at 20:42

Mother Earth News, I still subscribe to it… still has a lot of useful stuff in it, some just slightly more “yuppified”. Yep, love Mother, Popular Science and any gardening stuff I can get my hands on. Guess there’s still some old “hippie” in me ;-)

Hillbilly Bill – at 20:45

Kim - it never really goes away :-)

twoolf – at 20:56

I’ve got several compressors, condensors and evaporators from RX-7′s that were turned into race cars. I’m thinking about taking all these parts and building a gas powered refer / freezer using 134a (I’ve got the updated seals). My thought is to make unit to be accessed once a day, and powered with a small gas engine. I’m thinking an 8hp engine run 3 or 4 hours a day would use a minimal amount of fuel (1.5–2gal), but keep everything frozen. Any ideas on adapting automotive equipment to a use such as this ?

Eccles – at 23:37

hvac - Not quite what you say. That would be perpetual motion and doomed. What I’m looking at are two pieces of the puzzle using the same TE cells. One set of cells would operate in the normal fashion to pump heat out of the reefer. Unfortunately, as you are probably aware, they are only as efficient, or less so, than all of the plumbing stuff you like. The other half was looking at running them “backwards” and using the Seebeck effect to generate the power needed to run the reefer. I was thinking more like either a wood fire or perhaps a solar concentrator. Power from body heat is a parlor trick with little effective output (in my case here 170mv x 15 ma= 2.5 mw. hardly enough to recharge the 100 AH battery bay. But a cluster of cells running off of a really high energy heat source may have a very different output. I just need to work the equations and see how many cells it will take.

Then the rest of the work is finding a good cold source for the opposite side of the cells to maintain the temperature differential. perhaps running water run by a pump running from the cells……:-)

21 March 2006

Hillbilly Bill – at 08:00

Project update:

More than likely my freezer ran all night as it was still running this morning. Thermometer read 21 F and all bottles were frozen. I turned the power off and made sure the insulation was tightly sealed. I will check when I get home tonight which will be about a 12 hour span. It would appear that the layer of foam may actually hinder my model freezer in the initial cool down. I plan to open the panels up from now on when it is running and then seal them when I shut the unit off. Tests on how well frozen bottles will do in the cooler upcoming.

Kim – at 08:20

Can you fix the url I added at 17:46 that made a sidescroll? SORRY!!!!

Kim – at 08:41

Thanks for the repair, Dem!

hvac – at 18:10

eccles 23:37

im confused, if you cant find a colder source that 52 deg water then would it be better to increase the heat on the other plate? solar magnifiaction. is the increased delta linear to the output?

The im confused part is how does the te absorb heat with no fixed offset start point? and no i dont know a damn thing about te cells. once the process is “started” can you utalize the rejected heat to feed the delta?

Eccles – at 19:11

hvac - This requires a long-winded answer and I’m committed tonight. I’ll get back to this tomorrow and give you a better description.

22 March 2006

Hillbilly Bill – at 08:42

Project update:

Freezer: The thermometer reading in the freezer was 32F when I checked it. The freezer had been off for 12 hours and all of the bottles were still frozen. I turned the freezer on with the thermostat at the coldest setting, I didn’t want it to click off during the test. After one hour the reading was 21F. After two hours it was 20F. It would appear that the extra hour running added little value. I turned the freezer off and made sure the panels were in place and tightly sealed. This morning the reading was 34F and all bottles were still frozen. This more rapid temperature rise over a shorter time period makes sense as our house is warmer in the evenings and overnight than during the day due to the settings of the automatic furnace themostat. I ran the freezer for an hour and once more reduced the temperature to 21F. I sealed up the panels and left for work.

Cooler: I placed 3 frozen bottles into the cooler, it is a fairly large Coleman model with wheels and a handle. The ambient temperature was 70F and a quick check of the interior of the cooler got the same reading. After two hours the reading in the cooler was 55F. When I checked it this morning, it was dead on 40F. Only about 20% of the ice in the 2 liter bottles was melted, I’m sure that they could last for 24 hours and I am currently testing that hypothesis. I swapped out the bottles for 3 completely frozen ones and closed up the cooler.

So what does all this mean? It would certainly appear that it is possible to have 24/7 refrigeration in a cooler by running a generator to power a very slightly modified chest freezer for only two hours a day. Granted, this is a low-tech and inelegant solution, but it uses what I, and a lot of others I am sure, have on hand. It’s more work than we are used to, but that is the case with nearly every alternative method,(i.e. cooking, clothes washing, sanitation, etc.), we are looking at.

For those of you that know which end of a soldering iron gets hot and can follow simple schematics, Corky52 has presented above a nifty conversion of a chest freezer into a refrigerator. This plan would work very well for those on a solar/battery bank setup. For those that prefer whiz-bang electronics that seem to perform magic, stay tuned and Eccles will soon show us how to fool Mother Nature.

Hillbilly Bill – at 08:55

Additional notes:

While it appears that this method only takes 3–6 bottles of frozen water a day, you actually need about two dozen or so. The reason they all stay frozen while running the compressor for only two hours a day is a function of the mass of the water.

If I had it to do over again, and I probably will since I have only invested $15 at this point, I would not use the foam panels. Because of the peculiarities of my model freezer, I have to open them up when it is running, and then put them back in place when I turn the unit off. This is OK if you need to use the space above the water bottles, but a hassle if you don’t.

I would think that a thermal blanket folded to size and wrapped in plastic would work nicely. Remove it when running the freezer, place tightly over top frozen bottles when you turn it off. Also, you could cut fibeglas insulation to size and wrap in in plastic sheeting to make a dandy insulating layer.

hvac – at 18:29

eccles 19:11

i dont want to disrupt others with my own quests. if you have the time i would like to further this. Dem has my e-mail. if it was washed, ill gladly pass it on.

Eccles – at 19:17

hvac - I think my answer will be suitable for a broader audience. I have just been having some medical issues that have kept me off the Wikie much for the past few days. I’ll get those NiMH cells recharged and hopefully resume tomorrow.

Bill - Unfortunately, you can’t fool Mother Nature, and you can’t violate conservation of energy or the laws of thermodynamics. So all you can do is skate right up to the edge without falling off.

23 March 2006

Hillbilly Bill – at 14:59

Final Project Report:

My freezer was able to keep the water bottles frozen by only running the compressor for a total of two hours each day, an hour in the morning and again about 12 hours later. This is how much I am planning on running a generator anyway so I was delighted with that result.

Three frozen bottles of water were sufficent to keep the cooler safe for perishable foods for up to 24 hours. In warmer weather, or if the cooler were opened often, bottles should be rotated as needed.

I plan to keep the freezer ready to plug in if we have to quarantine. Not the best solution, but it does work!

IG – at 22:18

Hillbilly Bill- Many thanks for taking the time to summarize your experiment. Out of curiosity, how many months of fuel (propane, I assume) do you plan to keep on hand for the generator?

24 March 2006

Hillbilly Bill – at 08:18

IG - Actually, I have a gas generator. It is sufficent to run the items we plan to need to run, but I have a newer (and more economical) one “penciled in” for this fall. To answer your question, I plan to store about 100 gallons of gasoline. I have some now and I will be increasing that in the months to come (or really quickly if events warrant). I know that I will not be able to run the generator for an extended period on this much fuel, but I will have refrigeration for awhile. Individual condiment package are on my list of items to get soon.

I’m sure some may consider it folly for me to not have a plan in place that will last for 6 months or so, but if I may, let me use an anecdote to illustrate my viewpoint. A few years ago we added an additon onto our house. I did a good bit of the work myself (with occassional help from my wife and stepson), but for the roof trusses and roofing I enlisted the help of a friendly, local contractor that had the equipment and the experiences to make the job go much easier and quicker. As I laid the chimney blocks and bricks for the chimney, he installed the flashing. I told him that I was concerned about leakage and wanted to make sure that it was done right (that’s why he was doing it!). When he finished up, he sat back on his haunches, eyed his work, and said:

“I ain’t gonna say it won’t ever leak, but if it rains hard enough that it does, you’ll have lots of other things to worry about besides a little dribble around your chimney.”

My point, finally, is that if the electric grid is down for 3 months or more, I’ll have much bigger concerns than keeping my jar of mayonnaise cool.

Thom – at 08:31

Hillbilly Bill,

I have been thinking about gas storage – have you given thought to going to a junk yard and picking up an old tractor trailer truck type tank? The big saddle bag ones? They should 30 to 50 gals of fuel each.

Granted they would have to be cleaned (get rid of the old diesel) but with one or two mounted on a wooden frame you could store quite a bit of fuel in a safe, small area, and of course it would also have to be treated with StaBol or something.

Your thoughts? Is this a viable option for storage instead of 20 or so 5 gallon tanks?

Eccles – at 08:35

Indeed HBB - One of the thought processes that is sometimes overlooked in threads such as this, which are often heavily hardware related, is what is the larger picture.

If we need to improvise refrigeration for a period of a week or two because all hell has broken loose and the demons have infested the power grid, then they get it fixed, that’s one thing. If they have to go to rolling blackouts and you only get power every so often and need to learn to deal with that eventuality, that’s something else. But if you need to figure out how to refrigerate your food forever because the electricity has gone away and ain’t never coming back, then you are missing the point. If the infrstructure fails completely and is not restorable, then you are truly facing a situation so different that you need to realize that any other assumptions you have made about your future lifestyle and very existence are challenged.

In the event of the total collapse of the infrastructure, then all of the toy refrigerators we are playing with will pale by comparison of the much larger issues we will be facing.

Hillbilly Bill – at 08:36

Thom - I have thought about something like that. The deciding factor is whether I can find a decent tank for a good price. I have a detached garage, and also we have several secure buildings on our 75 acre farm, so storage of 20 gas cans is not a real problem for me. In my situation it really comes down to cost and availabilty.

Thom – at 08:43

Hillbilly Bill,

Thanks for the response – By any chance do you remember the estimated cost of the ones you looked at? I don’t have any idea what a ‘good’ cost would be (except if they were free).

Hillbilly Bill – at 08:46

Thom - Haven’t actually priced any, but that item is working it’s way to the top of my list.

Eccles – at 11:06

hvac - I just wanted to get back to clarify what was becoming muddled through my lack of time to post a full answer to our previous discussion. There are two seperate concepts that I am working on that have gottent combined due to my lack of detail. I will describe them individually here:

  1. A thermo-electric refrigerator based system. This would operate in a manner similar to what Hillbilly Bill is doing with his freezer, that is, cooling down a thermal mass when power is available, and then coasting for a long period without needing power. In Bill’s case, he is uisng ice as a thermal reservoir, and using a freezer as an insulated storage facility. When power is available, he removes the amount of heat which has leaked in through the sides of the case. From his results, it sounds like about 2 hours per day running the freezer compressor does it for him. My experiment has been to use a thick styrofoam medicine shipping cooler and seeing what the loss rate for heat is.
  2. A thermo-electric generator based power system. It turns out that a modern thermo-electric cell can not only be used as a cooler through the applicarion of the Peltier effect, but it can also generate electricity through the application of the Seebeck effect. The Peltier effect is well known and is used in Coleman and other brands of car coolers. It is fairly power hungry and is not usually as efficient as a well designed efficient compressor cooling system. In the Seebeck effect, electricity is generated through the exploitation of the temperature contrast between the two ends of the cell. Heat is consumed in the process, but as one might expect, it is not very efficient.

In the case of the thermo-electric generator, I would plan to use either a solar concentrator or a fire to provide heat to one side, while using cold water for the other side. Since this will take a bit of parts procurement and setting up, I woun’t be getting to it for a while.

Also, my Spidey Sense tells me that if it was so all-fired easy to do this to build a small field deployable generator capable of kicking out 10′s of watts, then they would already be readily available.

I hope this clears things up a bit.

hvac – at 18:03

eccles 11:o6

thanks for taking the time to elaborate

on point one the te based refrig would still be dependant on its output generation capacity to recover from the last cycle. unless you can sustain and generate the required peltier effect on a demand basis i see the system not aplicable. the support for such a system may consume more in generation than its ability to produce. (that is what i think stopped others) the variable loads between cycles are (imo) to unpredictable and the pursuit of the end result is unobtainable. the storage concept is a good one.

on point two i am with you on this. the problem it that the power required to become practical requires greater deltas or greated masses of dissimiliar metals. i dont know, but i think the process is non linear and the ratio (input/output) flattens out early. magnification is a great source it can be much more intense, adaptable, avaliable and more useful than fire. sitituation dependant.

i believe the ideas are there we need to unlock the obvious. how about not looking at dissimiliar metals as metals? how about the conductive reaction between liquids and metals? liquids of different brines?

gotogo feed the kids

Hillbilly Bill – at 19:31

Post Project notes:

Last post on this I promise. I use that chest freezer as a storage space for my dry goods. The last time the frezer was plugged in was Wednesday evening, and after checking the temperature Thursday morning, I opened up the foam panels and propped the lid open. This evening I started to return my dry goods to the freezer and was surprised to find that nearly all of the bottles still had a sizeable chunk of ice in them. Therefore I can still have refrigeration in the chest freezer for days after the last of my gasoline is consumed by the generator. I had a rather crazy mental image of myself drinking the last cold beer in existence as I listened for the mongel hordes to approach.

26 May 2006

BroncoBillat 01:09

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