Solar fridge and freezer

[PaulNKS]

I am responding to the following from a thread under General "The SHHT Fan....." so as not to hijack the OP's thread.

not bad at all,have you checked out the solar deepfreeze-with the dedicated solar panel?(costs about the same).Is the gas fridge an adsorption type?

Kevin,

The problem with that is that there is no way to use just a dedicated solar panel with a chest freezer or a fridge. As I stated, I do have a propane fridge and because of its efficiency, quietness, reliability, etc, I am considering a propane chest freezer.

If I was to try and go with the solar panel dedicated to a chest freezer, not only would it cost several hundred dollars in new PV but it would also cost money batteries that have to be replaced.... Also, I don't think it will last as long since it has a compressor...

The nice thing about the propane models is that they will outlast me because there are no moving parts to wear out and no compressor to fail with time.

Paul

[kmccune]

Well this setup is all inclusive,the whole shebang is intregrated-but if the propane works good-hang with it.- (I'm so paranoid about gas)Yeah the fewer the moving parts the better.Do you have a" Servel" brand? Kevin

[PaulNKS]

what "all inclusive" set up are you referring to? I've not seen one. No... I don't use Servel. I prefer Crystal Cold as far as a fridge goes but I haven't looked that closely at the brands for a chest freezer.

[kmccune]

Well you have the advantage on me there ,I lost the link-if I remember correctly the freezer or fridge had a 15 yr warrenty on the freezer& 25 yr on the solar panel the cost was right around $1800-Kevin

[PaulNKS]

What did it use for the power storage? Are the batteries included? How many watts in panels and how may amp-hours of battery storage?

[kmccune]

Well I been a browsen and not sure,I believe the one I was refering to,used batteries,another I found used 2 trojans,while another used good insulation&thermal mass-Kevin( Seemed like the panel was around 75 watts)

[PaulNKS]

hmm. I think in the long run the benefits of a propane freezer outweigh the benefits of the electric freezer since you have to add the batteries and the freezer will, in normal situations, have a shorter life span than the propane. Also, the batteries have to be replaced as needed. Most any good solar panel will be warranteed for 20 to 30 years.... But, If I go to the cost of adding an additional panel, it will be for whole house use.

I guess I just like the longevity, reliability, cost efficiency, and lack of needed maintenance of propane appliances.

[kmccune]

10-4,but propane is pretty expensive around here-but you are right ,if you dont use much & the maintenence is figured in-then propane is the clear winner-Kevin

[PaulNKS]

When you write about the cost of propane, are you referring to the 20 to 100 pound bottles or are you referring to bulk delivery? I take bulk delivery, which is a fraction of the cost in 20, 30, or even 100 pound bottles. Around here most propane companies will not deliver less than 200 gallons at a time. Also, we have several so, they are competitive enough to keep from gouging us too much.

[kmccune]

Well compressed gases used to be a bargain around here(maybe due to the proximity of the gas fields(cng) not propane.But propane being a premium fuel(good stuff I love it, still my preferred cooking medium) got so high cost it drove a lot of people to wood heat{maybe not a bad thing}. Anyway these fridges use a flame to boil the freon right?(ever heard of cool tubes?) what I'm getting at is any chance of using the the waste heat from the cooling cycle to warm water for domestic purposes?-Kevin P.S ever seen the wood fueled water heater the New England group developed?

[PaulNKS]

Kevin,
I agree about propane, but I don't use propane to heat with. I use wood. And keep in mind that a good quality propane fridge uses very, very little propane. The pilot doesn't "boil" anything and it isn't freon. There are two chemicals and one is a form of ammonia.... but I can't remember what type and I can't remember the other chemical. When the first chemical is heated, it rises in the tubes to the second chemical. As they mix, they form a reaction that causes freezing. This is used to freeze the items in the freezer. As the first chemical cools off, it drops down toward the level of the fridge keeping it cool, and as the chemical continues ot cool off it drops on down back to the pilot to be reheated.... sort of an extremely simplified explanation...

They do put off heat, and I'm sure something could be rigged up to heat water with it, but with the cost of these refrigerators, I'm sure as heck not going to go tryin' to alter it. lol....

[kmccune]

Makes you wonder why more Ammonia style freezers aren't in use 8) too cheap and effective I guess.I know there are some drawbacks-but with the current hype on flourocarbons-looks like NH3 would come back in favor-Kevin

[johnjmw]

The Ammonia style freezers are also available in natural gas though not as common. *The technology is old, turn of the century or older.
John

Here is another thread we had on the topic of gas refridges.
http://www.backwoodshome.com/forum/yabb/forum.pl?board=ene-other;action=display;num=1213276745

[PaulNKS]

thanks for that link to the other forum.

[gandalf1g]

Makes you wonder why more Ammonia style freezers aren't in use 8) too cheap and effective I guess.I know there are some drawbacks-but with the current hype on flourocarbons-looks like NH3 would come back in favor-Kevin
Because they are a safety hazard. Most commercial cold storage systems were ammonia, which is also a corrosive. When an exchanger ruptures anyone inside the cooler would suffer ammonia burns, both skin and lung.

[kmccune]

Thanks-also they needed a market for freon I suppose-Kevin

[johnjmw]

The Propane fridges I thought also were available in natural gas and kerosene. I was once told that the only difference between the natural gas and propane was the size of the orifice for the flame. Don't know if thats still true for the fridges.
When I get built down at my property I will be looking at these also. I still am not sold on which is better the gas or solar. They both do have thier advantages in different situations I think.
John

[PaulNKS]

John, there was a time when you could get refrigerators that operated on Kerosene. However, I don't think they are made any longer. Also, kerosene costs MORE than double the cost of propane.

As to solar or propane for a fridge, I am thinking you save much more money in the longrun with propane. The propane fridge costs more, but will last you the rest of your life. But a 12v or a 110v fridge has moving parts to wear out and a compressor that will have to be replaced much sooner than a propane fridge.

If you pencil out the upfront costs and the long term maintenance/repair costs, you will see that propane fridges are the better deal. They are very efficient with their use of propane.

[12vman]

Lehman's has it all.. ;D

http://www.lehmans.com/shopping/product/detailmain.jsp?itemID=557&itemType=PRODUCT&iProduc tID=557

http://www.lehmans.com/images/us/local/products/detail/!rk-400.f.gif

RK400 -- Kerosene Refrigerator

[PaulNKS]

Thanks 12v, I didn't know they still made 'em in Kerosene... Wouldn't that cost a fortune to run?

[12vman]

More Info: Dometic Kerosene Refrigerator


RK400 Kerosene
Total Capacity 8.0 cu. ft. *
Shelf Space 11.55 sq. ft.
Freezer Capacity 1.6 cu. ft.
Freezer Shelves 3.78 sq. ft.
Dimensions 70½"H x 23"W x 26½"D
Interior dimensions
Freezer 13"H x 17"W x 13;"D
Refrigerator 36½"H x 19"W x 15"D
Clearance Required 16" Top
Weight 230 lbs. shipping, 189 lbs net.
Energy Consumption
Fuel 1.5 - 1.75 gal/wk
Max burner output 2200 BTU

(Happy Birthday, BTW..)

[flatwater]

12volt , I have run a number of things on Kerosene and try as I might I would still get that Kerosene smell. Do you have a secret about no stinky of the keroseny

[12vman]

How's the wicks? Do they have any build up on them? (Black, chunky stuff) Is there any moisture in the kerosene?

Add a little dry gas (tablespoon/gal.) to your kerosene. Don't try to save fuel by turning things down too far. Don't run things too high either.

[johnjmw]

Yes there are parts that will wear out over time with the solar fridges but if the shtf do you think there will be a refill on propane? The cost of propane, Kerosene and natural gas will be going up. If you believe in peak oil (which I do) then you have to understand that the supply of propane is limited too.
Ok, I kinda have a gloom and doom outlook for whats coming in the future. This is one reason when I build it will me as self sustaining as possible. It's also why I have my property out in the middle of nowhere. Ahh but thats another story.
John

[Captain_Sternn]

but if the shtf do you think there will be a refill on propane?

All you need to do is re-jet for methane and buy poo gas. If propane doubles in price I think it will become cost effective to collect and pressurize methane from feedlot "leftovers". At this time it's just not a cost effective alternative.

[PaulNKS]

If things got that bad, I NO ONE would be using any kind of refrigeration including electric, which means preserving the old ways, and cooking only what you eat in one meal. But I don't see it getting that bad anytime soon... could be wrong.

If it got that bad, you wouldn't be able to buy replacement batteries for solar and wind, either.

[Bones]

Yes there are parts that will wear out over time with the solar fridges but if the shtf do you think there will be a refill on propane? *The cost of propane, Kerosene and natural gas will be going up. *If you believe in peak oil (which I do) then you have to understand that the supply of propane is limited too.
* * Ok, I kinda have *a gloom and doom outlook for whats coming in the future. *This is one reason when I build it will me as self sustaining as possible. *It's also why I have my property out in the middle of nowhere. *Ahh but thats another story.
John

Nice thing about these fridges are all you need is a heat source to run them. The kerosene one I saw when I was in the Bahamas (Andros Island not the resort Nassau) had a small flame so if kerosene/propane became unavailable then I see no reason why it could not be adapted to cool off of another flame like a candle. Small spring mount in the candle holder to keep the flame in contact with the evaporator as the candle burned down. Bee's wax candle or even a oil lamp (lard) would work as well.

[Dave]

If the proverbial pooh did hit the fan, I would look in to something like this for cooling: http://practicalaction.org/practicalanswers/product_info.php?products_id=240

The link brings you to an explanation of evaporation cooling used in 3rd world countries. This requires no fuel and just a few basic items. Naturally this will not make ice but will go a long way in preserving foods and dairy.

Could be life saving to some.

Dave

[PaulNKS]

I didn't take time to read it but evaporative cooling has been around for centuries. Have you seen the old crock water coolers? they were a big crock that had a lid and a spigot. They would use them in the old one-room schools. They would fill the crock with cool water and set it out. Somehow the condensation on the outside cooled the water on the inside. This was what an old man told me, but I still don't undertand how it works or if it really does. lol

[Dave]

Paul,

Literally the evaporation is what causes the cooling. The link actually gives a pretty good detail of a system used in India. I actually saw a special on this several years ago.

Ironically you are right, this has been around for a long time but recently has been rediscovered. This particular system uses two evaporation methods to enhance cooling (wet sand and a wet cloth cover).

In your particular example, the condensation would obviously evaporate to cause cooling but there would have to be enough insulation to prevent heat migrating in to the cool water from the outside, but you would think this would also insulate the water from cooling effect?

Dave

[sam12six]

Has anyone considered combining the 2 concepts here (solar and the absorption fridge)?

I haven't looked at the numbers, but I would imagine a small PV panel could feed a battery who's sole purpose was to run a small heating element to replace the propane flame.

Again, I haven't looked at the feasability (how much electricity/storage would be required, etc.), but if it did prove feasable, it would keep all the advantages of the propane fridge and add years of functionality (assuming you stocked a couple of extra parts like heating elements).

[PaulNKS]

You normally NEVER use any type heating element with solar. Heating elements are the most inefficient use of electricity that there is. That is why you cannot operate a furnace or a 110v or a 220v cookstove and oven on solar.

But, your idea would work in other ways if you could find a way to use the solar to heat in place of a pilot light. Then again, I think I will just stick with my propane.