100w a day chestfreezer
 

http://metaefficient.com/metaefficie...nt-fridge.html

Man Retrofits Freezer to Make an Ultra-Efficient Fridge

An off-grid experimenter in Australia, Tom Chalko, has retrofitted a chest freezer to create a fridge that uses only 100 watt-hours (0.1 kWh) per day!

full story in pdf http://www.builditsolar.com/Projects...est_fridge.pdf

For those of you who want to go solar.

Henk

I love the way that man thinks!

Looks like a winning idea to me. You might even be able to convert it into a side by side with a small freezer compartment that would keep the fridge side cool.

I've read other articles going back into the 70's of people that have done basicly the same thing. So this is not really anything new. Even read of a few that were custom built. They just never caught on because of the inconvience of a chest refrigerator.

Remember one that was a custom job that was only a foot deep inside. Reasoning was that you really never put anything in thats over a foot tall so that's deep enough. It was also built with isulation ratings of around r40in the bottom and sides. Lid was less like r20. It used like 25 watts a day if you didn't open it. Used an additional 5 watts for every time you opened it for 15 seconds. They also had a custom freezer done with similar results.

My initial reaction was that it'd be pretty inconvienent, but the more I think about it I don't think it'd be so bad. Our fridge is usually full enough that you have to crouch down anyway to find what you want, leaning into a chest fridge wouldn't be much worse.

I don't understand this one. If the freezer is working properly, shouldn't it not be running if the temp is below a certain setting?

When the electricity kicks off the coils are colder than the temp of the freezer (sensor not placed next to coils). The Freezer continues to cool as the coils absorb more heat until they equalize temperature with the freezer. There-by dropping the temp below the setting.

But once they equalize then the freezer should stop and not restart until the temp sensor goes above the desired temp + some delta factor right?

Yes. By the settings he talks about it restarts at a little over 7 Deg C

Somebody referred me back to this thread. Read the article including the pdf version. Quite interesting, but he doesnt mention any real detail of the thermostat. Is this a digital furnace thermostat, or if not, what was it designed for and where do you find one? Latching mechanism? How did he make it switch current off and on to the freezer? Some sort of relay? No experience with digital thermostats and even have to think back a bunch to vaguely remember the old mercury switch thermostats on furnaces. Been heating with wood the last 25 years.

HJohn,my same concerns.Wish one of the gurus here would build one with USA parts and stick a kill o watt meter on the before and after.That would really be nice to see.

booboo

Ok, little looking about and found this interesting discussion on same topic: http://www.wind-sun.com/smf/index.php?topic=1073.new

They are kinda figuring maybe twice energy use of what the Aussie is claiming but thats still very good. They also give couple links to auxillary thermostats to do just what the Aussie did with whatever mystery digital thermostat he used. Apparently people use these to convert refrigerators AND chest freezers into wine and beer storage. Who knew? And low tech so I can understand. No soldering required.

http://ceisites.com/9025.html

http://www.morebeer.com/product.html?product_id=16663

Oh, and one of guys posting said he is going to try it, has a new chest freezer on the way. Going to use it as a freezer if this experiment doesnt work out. I've got the site bookmarked and hope he posts back.

Maybe we are all a bit late to the chest refrigerator party. Look at the Crosley freezer with optional external thermostat to convert it to a chest refrigerator. Also the DC Sundanzer chest refrigerator.

http://www.backwoodssolar.com/Catalo.../refriger2.htm

Alas they dont give energy consumption figures for the Crosley used as a refrigerator.

Looks like he is using a 220 Volt kill a watt meter where can I find one. Actually I could use a half a dozen of them.

mikell

bump

I went today and bought a 7 cubic ft freezer------have it hooked up to a thermostat and plugged into a watt meter. Will give results in a couple of days. Randy

COOL, or at least I hope so.

Awesome Randy.

Here is my thoughts and my test. I bought a 7 cubic feet GE freezer from Wal*marts(sure there are more energy eff. ones out there). It was rated at app. 275kwh per year, thats about 775 watts per day. Using it as a refrigerator----Straight out the box it is drawing slightly less than 10 watts per hour, at that rate it will use 235 watts per day. Thats keeping it between 35 to 45 degree's, also it is empty. If I had alot of things in it, I feel it would take less watts per day to operate once what ever is in it got to the desired temp, but then again------if I was opening it several times aday---Hmmmmmm not sure. I think I will load it down with already cooled things from my other fridge tonight and see how it does. Its interesting!! More Later. Randy

Randy,whats a comparable sized regular refer using a day,do you know that?
Enjoying this thread a lot!

booBoo

Yes, do go on...this is facinating. Right now puzzled over how I'm going to have refrigeration without spending $1200 on a new propane fridge. I've got an old smaller electric fridge.... maybe If I SUPERINSULATE it and freeze a bunch of blocks of ice (from grid-power...) and stick them in there I can get my electric use WAY down. Gonna have to be WAY down in order to make this work with limited solar/battery power....


greg

(or maybe I can put the frigde outside on the back porch! No sunlight gets back there! That'd be nice and cold this winter). Sure beats having to spend over a thousand $$!)

This is interesting. According to govt data, an Avanti 8.7cu ft refer only (no freezer compartment and manual defrost) RM901W would use 230kwatt per year or around 630 watts per day. The Avanti line seems relatively efficient for smaller refer/freezers. So with Randy's prelimary findings the simular size freezer run as a refer is considerably more efficient.

Hmm, quick math....., the freezer run as a refer would save like $20 per year over the Avanti refer at my present 12cents per killowatt. However at double my present electric rate, which I can see happening sooner than I would like what with escalating energy prices, it starts making a significant difference. $40 per year savings would pay for the freezer in 5 year. And I doubt any ancient American refer even smallish and manual defrost would do any better than the Avanti RM901W so a simular size freezer run as refer would seem a good deal economically.

But this is extrapolating too far ahead. Need to hear how Randy's setup performs over couple weeks.

BooBoo--------You had to ask that question------------Got me to thinking(dangerous). You have caused me to start the process of getting another refrigerator for my shop. (I live off-grid, (gas fridge)but have a business on-grid that has a refrig/freezer in it.) I unplugged my kill-o-watt meter last night from my NEW fridge-project to test my old refrig, had to pull it away from the wall(the reason I have never checked it)-----plugged it into watt meter---------this morning--mercy I was shocked-----10 hrs later---3kwh exactly-------thats 300 watts per hr(7,200 watts per day)-------I am not sure about the cubic ft, probably around 12 to 15 but it is a refrig/freezer. I can't believe I have been paying app $25 per month to operate this fridge. I could buy another freezer like I bought yesterday- set them side by side("get-it" side by side refrig/freezer LOL)----it would use about 32 watts per/hr---the fridge project would use app 10 watts per/hr---------thats 42 watts per/hr--lets say 50(1200 watts per day for both) compared to 300 watts per/hr(7200 per/dy) mercy thats 6000 watts per day difference 2,190,000 watts per year difference(I just fainted)(don't no one figure how much extra it has cost me in the last 5 year (10,950,000 watts) (how long I have had it)to run that Beast)--I feel like I have been cheated--------Booboo this is your fault(THANKS) . I have been concentrating on my Off-grid place-----------But I think I need to check out more of my on-grid shop--------Money is Money. Going to plug the watt meter back into the new fridge project--Work with it some more---my heart or wallet can't handle the old one any more.
I might have to leave this freezer/fridge project in my shop and buy another for my home. As I said above, I have a gas fridge at my off-grid place, but I ran across a good deal on 17 solar panels(1200 watts) already had 320 watts, so that was the reason for wanting to go electric---if I could get this fridge to operate on app 300 watts per day----I feel it would work good with the 1500 watts of panels. Man, this was a shock this early in the morning----And it is still back there running---------Got to Go. Randy

PS-------Oh BooBoo----to answer your question-----I don't have a 7 cubic ft fridge to compare with this freezer deal. I have one of those small fridge's--about 18"x 17"x18"(small) it was using app 30 watts per hr compared to the 7 cubic ft freezer/fridge project at 10 watts per/hr--compared to the side by side at 300 watts per hr(The Beast).

WOW!
So in 2 weeks or so will you put the daily usage of your coolers up in a side by side(LOL) comparison?
Like how much per day,and temps averages,things like that?Oh and how about propane use and costs per day of the propane and the electrics at your true Kw/hr rate(including all the fees,not just the 12 cents per Kw charge)
Also,can you run the freezer for a couple days at zero degrees and give us that number?Maybe freeze some water bottles or such so we know what the usage would be like in the real world of freezer with food.

What kind of deal did you get on the panels?What type inverter do you use,and does it idle?At what watts does it turn on?


Thanks a lot Randy,this is an incredibly useful thread and I would REALLY like to thank you for this info :cowboy:

Soooo....should we all have kill o watt meters and do you recommend a particular dealer?


BooBoo

BTW,you all using compact florescent bulbs?

We can get them here on sale with an instant SCE rebate at the checkout,works out to about 1 dollar per bulb.

The bright lights in our living room is up on an 'A' Frame ceiling fan(About 11 feet up).It has 4 bulbs.We used to have 4-100watt bulbs.Now we have 4-27watt CFs that put out just as much light,and they last 'forever'(well,a long time anyhow).Since 2000 I have replaced one.

We save 300 watts/hr just from that simple change over.At 15 cents per kw/hr thats 15 cents saved every three hours/day average usage.Thats 4.50 a month.

Bulbs paid for themselves in one month.

CFs are simple, very considerable savings,and a fast payback.Gotta love em.

BooBoo

At 15 cents kw/hr,your old frig costs 394 dollars a year to run. :eek:
Your new combo would cost 65 dollars/year if the preliminary numbers pan out. :bow:
saving you 328 dollars a year,or 3280 dollars over 10 years. :eek:

Maybe someone should recheck my numbers.I used 50 watts/hr X 24 hours X 365 days for the combo,divided by 1000 x .15 cents per Kw/hr.

Old refer 300 watts/hr X 24 hours X 365 days divided by 1000 x .15 cents per Kw/hr.

Divided by 1000 to get Kw/hrs,correct?

BooBoo :buds:

I got lucky on the panels. I got 8-100 watt & 1-50 watt plug-n-play, 2-120 watt, 6-15 watt, 2 Trace C-60 charge controllers, 2-3000 watt cont. inverters(Galaxy, Vector Maxx) 8 T-125's batteries(All Good), then there was boxes of 4/0 jumper wires, disconnects, 2 isolators, fuse blocks, 10 breaker panel generator switch over box, amp and volt meters, 3-12" 12 volt attic fans-----Hey Man-----there was a Pile's of stuff and everything looked Good to New. Hey, You like Fun--------Guess what I payed for All. I can tell you the 17 panels at the cheapest price I could find for What I got was $9500, new on the computer, but that was the panels alone. The two C-60 were between $150 to $200 each. The generator switch box still had the price on it--$289--------I figured app $13,000 for the larger things, but there was lots of small things. It was not free by no means, but I got it at a Good Deal!!

On Gas fridge-------I don't know what it takes because I live alone and only use the gas fridge when my G/F is coming for the weekend. We are planning to get married in about 1 year(she has to relocate here(40 minutes away) and its her daughters Senior Year--waiting till she graduate's), I am trying to get everything ready for her arrivial. My Business is about 1/2 mile from where I am living------I hang out in it most of the time. I basically Sleep and shower where I live---Watch TV at night some. I never cook there unless she is staying for the weekend. When we get married, we want everything ready so we can stay back there and only go to the "Shop" only when I am open for Business. She is a Outdoor Woman and LOVES my "Homestead" place.
The Inverter I am using right now is a Cobra 2500 watt. It cuts off at app 10 volts. I have a 3/4hp water pump and TV. a pool pump draws about 110 watts, but I only run it a couple hrs per day, Right now I have a bittie brooder that I run at night, draws about 150 watts while on(got to keep them Keets warm). I always have plenty of electric(solar), but I am sure I will have to conserve when her and her 7yr old son move in with me-------LOL-------cut that lite and tv off Boy-------Will probably be my most used words--LOL. Got to have enough watts to run that NEW FRIDGE/freezer. WE will be using solar water heat for hot water with wood water heater back-up. Our gold is to try to be able to live months at the time with out leaving our "homestead". That is one reason to try to cut down on the gas used. WE will cook out in the yard most of the time using wood cook stove under a small screened in shed. We want to work only part-time for insurance and supplies. Hey this is my Dream---LOL!! Randy

Ok,lemme guess,about 5 grand?Now you did say guess......
Thats how I got my system,a guy who was selling out to move back ongrid.Paid 1200 I think for close to 3000 worth of stuff.Figured I paid retail for the 8 L-16s(2 years old), the controller,remote, 2 panels 75 watt monocrystallines,mounts,wires,cables,fuse and inverter/charger free.

Plus guy kept throwing on stuff for next to nothing,want these lanterns,need a BIG extension cord?Want these 2 solar heating panels,i cant use em,2 old wagon wheels(wife wanted em so.....)......Sell this washer cheap(gave to nephew.) Think it was 1350 out the door,something like that

Wound up with a home power backup and solar for the Winnebago.Need more deals like that.

Like your plan.You got a really nice system there,and it still has room to grow,mighty fine!

GF sounds like Mrs,she is excited to go offgrid and primitive so to speak,but we will only be reducing power,not giving up modern life.

BooBoo

2 Grand---thats $2000-------I think the man that built the system --not sure why, but his house was sold-------The realitor, bought the house to resale Had to reshingle the house---All the panels had to be removed. He ran a add for the solar panels and things. I got Lucky------------Hey, He made the price and also told me he knew the things were worth thousands. I came Home with a BIG smile. Randy

Wow!!!!!!

Where can you find the battery operated thermostat?
 

Anybody know where the guy got the digital thermostat? I've been googing but haven't been able to find it.

I havn't been able to find it either. Don't know if I'd want to trust everything in my frig to me remembering to replace the battery though.

That 'more beer' link I gave to analog thermostat also has a digital thermostat though I dont think it has a battery like the Aussie fellow used. Here is link directly to digital version: http://www.morebeer.com/product.html...3481dcef642f96 Both analog and digital thermostats for this conversion apparently are common enough in homemade beer and wine supply places. They use them to convert freezers not only to store their product but to ferment it in a controlled environment also.

What I am using is a thermostat out of a old fridge. The digital would probably work better, but this one is working good. This one causes the temp. to range 10 degree's give or take one or two(keep in mind the contents temp hardly change at all). But if you used a digital and set it to have a 2 or 3 degree turn on--------the compressor will come on more times per hr. When the compressor comes on it will draw about 180 watts, but will drop the draw wattage in the first minute to app. 110, then it stays at that till it turns off. I set the thermostat a little lower last night to see what it will do--------it drawed 14 watts per hr, the gallon of water I had in it was 33 degree's this morning. I feel this is as little to cold for a fridge, so I raised it back up a little. 14 watts per hr at the point of freezing was(to me) not a bad draw at all. One 80 watt panel with only 5 hrs of sun per day could handle that, but I like the 240 watts per day better. If I would set it to where the contents were app 40 to 45 degree's, I am sure it will draw less than 10 watts per hr. I will probably buy a digital thermostat but I would want a 5 to 10 degree turn back on, which these Dig. thermostats are adjustable. More results Later. Randy

How much power do non-digital temp controllers use?
 

I would like the digital as I am unsure how much power the other ones use. I'm off grid.

My current refrigerator---
 

I just moved my "Kill A Watt" meter to my refrigerator about two hours ago from another application. The refrigerator has cycled twice in two hours and shows a total consumption of .05 KWH during the two hours.

The unit is a 7.9 cu. ft. Haier that I bought from Lowes. The manufacturers label on the unit shows a 1.4 amp draw when running, but my Kill A Watt meter shows it actually using less. Since putting the unit into service one or two years ago my electrical bill hasn't gone up much at all.

I try to defrost it every two weeks. I"ve found the quickest way is to put something I want chilled into the freezer compartment. Heat is drawn from the warmer product and melts the frost quickly. Since I don't let the frost get thick this only takes a few minutes. The items get pre-chilled and ready for the fridge section and a quick cleaning of the entire unit only takes a few more minutes as well.

Has anyone thought of using a conventional refrigerator or a small one like I have and turning it on it back and relocating the compressor to still be upright? Might be cheaper than buying a freezer to convert. Would the refrigerant still go to the compressor unit all right? That would solve the upright door losing cold air when open.

Interesting article. Thanks for posting it for us to read and consider.

[QUOTE=copperhead51]I would like the digital as I am unsure how much power the other ones use. I'm off grid.[/QUOT

The one I am using out of the old fridge uses no electricity at all. It just breaks one power wire---like a switch on your wall. It was taken out of a old fridge. It only took 1 minute to take it out. Using it would mean I will have to mount it some where inside the freezer---but its not that big---that is why I was planniing to buy a digital------only the probe/censor will go inside the freezer and you can controll the temp better. But as I said above--------I feel if you keep the temp range between 2 to 3 degree's-----the compressor will turn on more times per hr, causing it to draw more watts per hour. Randy

Your fridge is about like the small one I checked---------your's is drawing probably between 25 to 30 watts per hour,(.05 is 50 watts) which would amount to 600 to 700 per day----My fridge/freezer would be on .60 (600 watts)in 2 hours----run it for a day-----your kill-o-watt meter has a clock that tell's you how long it has been plugged in. Randy

Next test-------------- I turned the freezer/fridge(F/F) down to where it is keeping contents around 46 degree's-------gave it a couple of hrs to re-adjust, then plugged in the watt meter------------drawing 7 3/4 watts per hour over a 12 hr period-------less than 200 watts per day. If you only got 150 watts per day to spare, turn it down some more--------I could drink 50 degree soda or tea better that 80 or 90 degree. I got to do the big test now, I got to move the F/F to my off-grid place and see if the results are about the same with it running off the inverter. Will try that in a couple of days. Randy

Any updates? I am really headed in this direction I think. Been thinking a bit on how to efficiently use interior space of freezer for refrigerator use. It is going to be bit awkward to say the least. And I also have to figure on needing a second freezer as a freezer since no freezer compartment in a freezer used as a refrigerator. I had been wanting a small chest freezer for freezer use anyway.

OK------Updates. When I hooked it to the inverter it drawed 13 1/2 watts per hr over a several day period, a little more than on line, but the inverter voltage was 116 compared to on-line at 123. I was curious as to how long it would run on a Wal*Marts deep cycle battery, one of those yellow app $70 one's(didn't check amp/hrs on battery and I am not there now to be able to check it) I already had this battery for my trolling motor, I made sure it was full charged. It ran the freezer 65 hrs(inverter shut-down)--keeping contents app 40 degree's in a room that stayed app 82 degree's, but the freezer/fridge was about empty and I only opened the lid 2/3 times per day and only for a 10/15 seconds each time. The reason for using the above battery is--I don't have my Cabin built yet, and I live in a 34ft camper where I am building the cabin--so I did not have a place to set it other than outside to hook it to my solar set-up. I was checking this out now so if I decided to put this in my cabin when built------I could plan a place for it, and I promice you it will have a place in my cabin---unless someone comes up with a better idea before I get it built. My G/friend and I decided we would put it on roller/casters so we could move it around to help conserve also-----meaning in the winter if I am wood-heating the cabin and keeping the temp 80 degree's, we could roll it to a unheated room or even the front porch if it was real cool outside--I feel this would help some. But we are still planning to instal a gas fridge as a back-up, but only use it if we get several cloudy days in a row.
So my test -----if the room it is in is in the 80's it will draw app 325/350 watts per day. The man that started this deal was testing the 100 watt per day fridge in a 60 some degree room, even he stated and common sence will tell you the hotter the room is-----the more it will draw. He did a follow-up on the digital thermostat and said it would not hold up and he had to make changes. So if any of you decide to get the digital thermostat---make sure the contact rating on the relay is rated high enough for your fridge. I feel if it was not or to close, you could allow that relay to switch on a heaver relay that would be heavy enough. I really like the old thermostat that I took out of the old fridge---It has worked good. OK-Any Questions?? Randy