Box Seals

Down in Mexico we can at times have problems finding stuff. In most cases when making sure the box has a good seal on the opening we use a foam rubber tape which is readily available and you get good service from it, perhaps you need to replace it every few years? Some of the newer boats such as Hunter have a more elaborate seal. It seems that after several years they harden up, maybe because of ozone or perhaps due to a cleaner used.

Here's a link to where you can find what you need and bring it down with you. Thanks to Colin on Pacific Raven who researched it.

http://www.cooler-gaskets.com/

OK I know I've bored you with too much tech talk: Here follows some Brit Humour

http://www.mez.co.uk/lucas.html


Enjoy

Cabo San Lucas will never have that allure when you realize it was named after Joe Lucas

a.k.a The Prince of Darkness

RETRO FITTING KEEL COOLED SYSTEMS

Over the years Mexicolder has retro fitted many systems that use through hull keel coolers.
These systems use the exactly the same compressor as does the Mexicolder. Even water cooled systems are less efficient as the energy used to power the pump takes more from the system than it gives....An ever increasing entropy.

The disavantage is that when you are hauled for bottom work you lose all your refrigeration.

The  alarming defect in the system is that in tropical waters the keel cooling plate and or associated through hull fitting is too small to efficiently remove heat from the hot condensing refrigerant gas.
This is evidenced by simply measuring the temperature of the liquid refrigerant after it exits the condenser/keel cooler, this enthalpy curve allows us to determine ho much energy is lost due to the FACT that small through hull condensers offered on several off the shelf systems are very inefficient in tropical waters.

 http://www2.dupont.com/Refrigerants/en_US/assets/downloads/h39917_hfc134a_pressure_enthalpy_eng.pdf

If the liquid refigerant temperature is significantly higher than ambient air or water temperature then you have a huge inefficiency built into the system as when the above ambient liquid refrigerant vapourizes  it is heavily taxed by reducing it's temperature using the  "latent heat of vapourization of HFC 134a", which was supposedly going to be used to take heat from the evaporator. If this is too technical for you, just trust me it follows the second law of thermodynamics.

http://www.grc.nasa.gov/WWW/k-12/airplane/thermo2.html

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookener1.html

The  fact....is that in 20 plus years of using the Danfoss BD series compressors these are the only failures I have seen. Here is an example

http://www.sailblogs.com/member/followyoufollowme/?xjMsgID=76920

Read the third blog entry down from the top  Refrigeration 101 and 102 



The retrofit involves installing a double air condenser within the system.

My client jokingly failed to see how this would use less energy than the static keel cooler as the fans pull 0.34 amps. Let's say this guy is no dummy and is well versed in engineering. A year later I returned to retrofit his second system as he had spent a year monitoring the retro system and this was the icing on the cake (pun intended). It used considerably less energy.

I will try and get the results directly from him to prove this fact so keep an eye on this space.

Well here it is from the horses mouth..so to speak:

Hi Mike- I read you blog and found much useful information, good job. Regarding the retrofit you did on my boat, Sandpiper, an island packet 420. You may recall when I purchased the boat it had a stock refrigerator/freezer with two separate compressors using keel coolers. In southern California, my home waters, these operated well because the water temperature is quite low, typically between 55 and 65 deg F. However when I took the boat to Mexico the time to cool down became noticeably longer. The first problems occurred with the freezer when the copper tubing connection to the keel cooler corroded through with resulting loss of coolant. Because these connections to the keel coolers are necessarily located in the bilge areas they are prone to salt water immersion and can easily corrode. The keel cooler manufacturer did not offer any solution other than to replace the cooler plate. The quoted cost to haul the boat and replace the keel cooler plate was around $5,000. Lucky for me your solution, to replace all seals and fittings with a fully welded system and to use a large volume Mexicolder fan instead of keel cooling was only a small fraction of the cost compared to replacing the keel cooler. In the two years since this was done I have had only good experiences with the air cooled system. Running side by side with the refrigerator system (still keel cooled) it was easy to see the differences. The freezer ran for half the time of the refrigerator and used approximately 30 A-hr per day. In the summer heat, the outside water often reached into the 80-90 deg range and the refrigerator compressor ran almost continuously. Based upon this experience I elected to have the refrigerator system also converted to air-cooling and since then the total drain for both systems is approximately 60 A-hr per day. As a bonus I no longer worry about corrosion of cooper tubing in the bilges. 
Best regards,
Ed Staples
S/V Sandpiper

It would seem that some smart advertising and business types have sold cruising sailors down the road on these systems? If that is the case at this miniscule end of "heat transfer pumps" It makes me shiver to think as to where big industry is and how much precious energy is being wasted on this planet?

I rest my case

A video link that will show you how regular simple maintenance will save lots of precious solar amp hours

Although the system you will see when you view the video on this link is many times bigger than your tiny boat unit it operates ON THE EXACTLY THE SAME PRINCIPAL as a Mexicolder system

So occasionally vacuum any dust or dirt off the condenser fins. Defrost on a regular basis and and make sure the box seals are in good condition. You'll get the same benefits shown on the video. The energy savings you'll enjoy will be less amp hour usage

As the Mexicolder is a hermetic system ( ie it is fully welded and there are no mechanical connections seals or motor alignment issues) this is all the maintenance needed. The other failure and maintainance points do not apply, they were engineered out of the loop! (pun intended)

Enjoy,

http://www.ecacool.com/en/videos/video-animation-starcare-industrial-refrigeration-maintenance-industrial-refrigeration-commercial-refrigeration-video.html

Stuck somewhere with a problem no one seems to be able to fix?

WHAT'S THE PROBLEM MATE?

We offer on line consulting. Search for MexiColder on Skype  or send me a mail at mexicolder@hotmail.com and I am sure I can help you get stuff working in many cases.

I am a Marine Engineer, not a technician with a little basic knowledge. I have 36 years SOLID experience in the Marine Industry. I have overseen the construction of Yachts and Megga Yachts, sailed them, delivered them, and have professional qualifications to back all this up.

So you may ask what I'm doing building energy efficient fridges?

 I enjoy it!

 On a big steam plant you maybe dealing with 50,000 horse power and these little fridges 1/16th of a horsepower. Not much room for error, but it all works on the same heat laws and principles of thermodynamics.

 I guess it's akin to making jewelry versus building power stations?

A new box

The galley was fully gutted on this C&C 38. The insulation was only 2 inches thick and it was wet. There was a huge void between the hull and the box liner. Now it's all foam and monocoque with the hull. Another beautiful job that will give many years  of use and YES it's easy to keep clean

Spare parts for ANY system

We have a huge selection of spare parts for almost ANY system and can ship to ANY Mexican Marina, Business or home address, you just need some one to sign for the package.

 Tell us what you want, give us a full description, include the part number and the type of system it is going into.


We have it all in Mexico already saving you the cost and hassle of sourcing it north of the border and going through the typical customs nightmare!

Pictured is a Danfoss BD35 compressor complete with mounts, the 101N220 control module, a thermostat, fan and filter drier.

  Just email us at mexicolder@hotmail.com and we'll have that part to you quicker than a Mexican mañana.

Unsolicited email

• Power Test‏

Pacific Raven Colin and Margey (colin.harris1950@gmail.com)

4/16/2013

Documents

To: Mike Wilson

MEXICOLDER REFRIGERATION RESULTS

Data collected on April 15th, in Mazatlan, Mexico, using a Xantrax Link 1000 Digital display, aboard Sailing Vessel “Pacific Raven”, Hunter model 40.5. Mexicolder evaporator installed in the freezer box, wall between freezer box and refrigerator box removed to allow cold air to circulate throughout. Other than the removal of the separating wall, the units are stock Hunter, 4” foam covered with a molded fibreglass surface. Note that gaskets on the sealing doors are due for replacement and are definitely leaking due to hardening. Upon replacement these recorded results should improve.

Day time: Recorded during the warmest part of the day, 1100-1600 Amp hours used during the 5 hours = 6.0 Average consumption during the period = 1.2 Amp hours per hour, or 15 Watt hours per hour Day-time average of 30 Amp hours per 24 hour day, or 360 Watt hours per 24 hour day Combined average is estimated at 27 Amp hours per 24 hour day, or 310 Watt hours per day

Night time:

Recording time 2200-

0800 April 16th Amp hours used during the 10 hours = 10.0 Average consumption during the period = 0.9 Amp hours per hour, or 11 Watt hours per hoMEXICOLDER REFRIGERATION RESULTS

Data collected on April 15th, in Mazatlan, Mexico, using a Xantrax Link 1000 Digital display, aboard Sailing Vessel “Pacific Raven”, Hunter model 40.5. Mexicolder evaporator installed in the freezer box, wall between freezer box and refrigerator box removed to allow cold air to circulate throughout. Other than the removal of the separating wall, the units are stock Hunter, 4” foam covered with a molded fibreglass surface. Note that gaskets on the sealing doors are due for replacement and are definitely leaking due to hardening. Upon replacement these recorded results should improve.

Day time: Recorded during the warmest part of the day, 1100-1600 Amp hours used during the 5 hours = 6.0 Average consumption during the period = 1.2 Amp hours per hour, or 15 Watt hours per hour Day-time average of 30 Amp hours per 24 hour day, or 360 Watt hours per 24 hour day Combined average is estimated at 27 Amp hours per 24 hour day, or 310 Watt hours per day

Night time:

Recording time 2200-

0800 April 16th Amp hours used during the 10 hours = 10.0 Average consumption during the period = 0.9 Amp hours per hour, or 11 Watt hours 

• 

Outlook Active View

MEXICOLDER REFRIGERATION RESULTS

Data collected on April 15th, in Mazatlan, Mexico, using a Xantrax Link 1000 Digital display, aboard Sailing Vessel “Pacific Raven”, Hunter model 40.5. Mexicolder evaporator installed in the freezer box, wall between freezer box and refrigerator box removed to allow cold air to circulate throughout. Other than the removal of the separating wall, the units are stock Hunter, 4” foam covered with a molded fibreglass surface. Note that gaskets on the sealing doors are due for replacement and are definitely leaking due to hardening. Upon replacement these recorded results should improve.

Day time: Recorded during the warmest part of the day, 1100-1600 Amp hours used during the 5 hours = 6.0 Average consumption during the period = 1.2 Amp hours per hour, or 15 Watt hours per hour Day-time average of 30 Amp hours per 24 hour day, or 360 Watt hours per 24 hour day Combined average is estimated at 27 Amp hours per 24 hour day, or 310 Watt hours per day

Hi Mike - the system appears to be working very well. Even though we are cooling a much larger area than before, the unit is running much less. I've attached some numbers that you may be interested in. Once the gaskets are replaced and also with the freezer boxes full of cold food I figure the numbers might even get a little better. The Nova Kool that was removed was using something in the order of 60 Amp hours per day, so the Mexicolder is consuming less than half. If this performance proves out during our cruising next winter we will be delighted. Thanks Mike

I'm heading back to Canada tomorrow, hope you have a good trip to the Sea, see you in October.

Kind words from Fresco Don May

• Testimonial‏

Fresco Don (Frescomexico@aol.com)

3/11/2013

To: mexicolder@hotmail.com

• 

Hi Mike,

Just by way of recommendation for Mexicolder refrigeration systems. I have been servicing boat refrigeration systems in Puerto Vallarta since 1995. Many boats, on their way to points south, pass through both Mazatlan and Puerto Vallarta. In all these years, I have never had to service a single Mexicolder installation. If all systems were as good as yours, I would starve to death.

Regards,

Don May

Fresco Marine

Refrigeration Service

Specifications

MexicolderTM

TROPICAL YACHT REFRIGERATION SYSTEM

BASIC SPECIFICATIONS mexicolder@hotmail.com   

*Constant cycling, super efficient, 12 volt direct current, vapour compression refrigeration system. Uses “Ozone Friendly” refrigerant

 HFC 134a. and ester based P.O.E. oil.

*High quality components used thoughout.

*304 stainless steel skid, condenser end plates, fasteners and fan housing. Foot print of skid is 14.25” long x 10.25” wide x 10” high

*Double capacity high volume air cooled condenser with dual cooling fans.

*Copper-phosphorous brazed connections thoughout. Unlike other systems, there are  no mechanical connections to leak.

* Dual speed Danfoss/Secop compressor, draws less than 4.0 amps on low speed and less than 5.0 amps on high speed. Actual tests in a box of 6 cubic feet with 5” of insulation proved an average electrical consumption of less than 1.5 amps/hour with a 24 hour average ambient temperature of 75ºF (23.9ºC)

*White   20ºF (-6.7ºC) evaporator box provides more frozen storage than other popular systems on the market. Cools ice boxes to 15 cubic feet. External dimensions of evaporator are 17.5” long x 8.25” wide x 11” deep.

*Unique snap apart design for electrical components and thermostat.

*Designed & field tested in ambient temperatures over 100ºF (37.8ºC)

Got questions? We have the answers and some Images

F.A.QS.

 Do I need water-cooling for the fridge and freezer?

 No. For the amount of heat/hour the Mexicolder removes from the box, water-cooling is ABSOLUTELY unnecessary, In fact, with a water-cooled system, the energy to power the pump uses more precious amp hours.

We are concerned about the heat from the system warming the interior of the boat in the tropics.

A typical box installation

The radiant heat from sunlight on the deck, cabin and hull far exceed the heat produced by the Mexicolder, in short you won’t notice the difference. Boiling a kettle of water for 2 cups of coffee or cooking creates much more heat than a Mexicolder.

 I have seen keel cooled systems advertised that do not need a fan or a pump, will this work for me?

Yes, we built several prototypes that worked, BUT…….. Nothing comes for free and for this reason Mexicolder uses air cooling, When you are hauled out for underwater maintenance the keel cooling system did not work and when left on it damaged the compressor which is the heart of the system. Imagine being in a boatyard for even a few days and loosing those cold drinks and ice when you need them the most?  Not to mention a freezer full of meat or seafood. In addition to the former you have to bore a 1 ½” hole though the hull and pay for the haul, launch and labor to do so. Even though keel coolers are made of bronze they are still susceptible to stray current corrosion. You don’t need to haul out to install a Mexicolder, or ever need worry about future corrosion issues.  

 There are other systems on the market that use cold plates and high capacity compressors, they cost many times more than a Mexicolder and then there is the install to pay for, so even if cost were not an issue, why wouldn’t I opt for one?

Cold plates are history, they are heavy, and they occupy the well-insulated box space you have supposedly created to store food in!  They are problematic as most require expansion valves with mechanical connections that are prone to refrigerant gas leaks. Often they use a larger compressor and lots of associated and sophisticated control equipment to cool them so that means even more weight in batteries and heavy cables to supply the current. Add to this mélange the solenoid controlled valves, multiple wiring blocks, looms, suction accumulators and suction control valves………so much more to go wrong.  Ask Nigel Calder.  

What about engine driven systems?

In our opinion they are history too. From their first introduction and our personal experiences they were one of the most problematic systems we ever had or have worked on. In short, the operating pressure of the compressor at the end of the cycle is lower than the compressor was designed for in its role as an automotive air conditioning system. This often causes problems with the shaft seal and the system can get shut down due to moisture entering past the seal. The other disadvantage is that you are literally bound to your vessel, as the engine must be started at least once a day. Say goodbye to extended inland trips.

Do you offer “ high tech” digital controls?

No, the simple thermostat does a great job and is trouble free. If you insist, yes, we can custom install all the “bells and whistles” you desire, however we will put a switch in the system so that if you ever get hit by lightning, have a power surge or the digital control gets knocked out by your h.f. radio transmissions you have the option of having a simple, reliable thermostat.

Why is a high capacity compressor that I see advertised, advantageous?

It is not, as heat moves very slowly, and even more slowly as the temperature drops.  

1.Think of your fridge box as the bilge and the fridge system as a bilge pump and the bilge water as heat.

2. If you had a lot of water leaks into the bilge you would want to stop them, this equates to building a well-insulated fridge box, thus stopping heat leaking into the box.

3. If you have a well-insulated fridge box, you have a smaller heat leak into the box and so you need a smaller more efficient pump (fridge system) to remove it at a regular interval.

4. Try sucking a cup of water out of the bilge with a 1 ½” hose size pump, then try with a ¼” hose size pump and you’ll understand.

We need both a fridge and a freezer; do we need to buy two units?

No, in almost all cases if the boxes are next or near to each other the cold air that spills over from the freezer box will keep you drinks ice cold and veggies fresh and crunchy. We built a custom system that use a small circulating fan and insulated 2” pipes to cool an auxiliary box when the boxes are split either side of the galley range like on the Catalina 42 “Ceilidh”, this works very well, the information can be found on this blog.

Assuming we purchase and have you install a system, what happens if we need spare parts in New Zealand or somewhere else on our circumnavigation?

All the moving components in the system are available in any developed country anywhere in the world. The system was designed with this in mind, we have been there! We offer a cruisers spares package  for those going further a field. The key to the energy efficiency of the system is engineered within the static internal design features.

Where did the Mexicolder system come from?

An ANSWER to SATISFY hundreds of sailors who, over the last  31 years worldwide asked us  “why can’t I have a boat fridge system as reliable as a domestic fridge/freezer?”

Good QUESTION…why not?

We took a blank sheet of paper and years of hands on experience. Then we wrote down all that was good and all that was not good of all the systems available on the market in the mid 1990’s. We kept the good stuff and then tested and tested and tested aboard a cruising sailboat in the severe heat conditions during several summers in the Sea of Cortez Mexico. We then removed all the excess moving parts that were “fluff” but doubled up on the stuff that kept the compressor or “heart of the system” beating nicely.  Then we chose the finest quality materials to build a simple, lightweight and efficient answer to the sailor’s needs and dreams.

 Where can I have a Mexicolder installed?

At the time of writing in Mazatlan Mexico during the months October through May and during the summer in and around the Sea of Cortez, we have all the equipment and tools to install anywhere!. There are independent contractors who can make box modifications, or all the materials available to do it yourself. Check out " Building a box" later on posts.

Energy usage

MexicolderTM

TROPICAL YACHT REFRIGERATION

mexicolder@hotmail.com

Mexicolder Usage Aboard CEILIDH

Measurements

Local

time On Off % on

2100 167 283 37% Thermostat set at 4-3/4

Freezer temperature 23-24 °F

Main box temperature 35 - 38

degrees °F

Vegetable box temperature 55 +/- °F

s/v ceilidh, Catalina 42, April 2004

166 285 37%

0700 149 356 30%

151 362 29%

1115 177 341 34%

175 338 34%

1630 186 285 39%

196 302 39%

2015 184 320 37%

185 332 36%

0820 170 369 32%

168 375 31%

1300 207 326 39%

1800 210 309 40%

2030 195 336 37%

0815 189 379 33%

0730 204 487 30%

Average 181 340 35%

Mexicolder

averaged daily load

40.0 Amp-hr / day

(4.8 amp draw 35% of the time)

 Original Alder-Barbour

averaged daily load

70 Amp-hr / day

(6.0+ amp draw 50% of the time)

Measurement Notes: Box insulation improved to Mexicolder standards, freezer box 2-1/2

size. Ambient daily temperature cycle 70-88 degrees F. Hull side of box in sun from sunrise

to noon. Evaporator (freezer) box and main box kept 1/2 to 3/4 full. Measurements in

seconds & made with stopwatch over several days. System includes 2-inch PVC tubing runs

with a circulation fan to a forward, larger, unimproved box used as vegetable cooler.

Original Alder-Barbour Notes: Old system started up at 7.0 amps for a few minutes then

came down to around 6.1 amps for duration of cycle. Original Catalina box insulation. 65-75

Amp-hr/day agrees with daily observations on a Link 1000 battery monitoring system made

in SF Bay California during summer and cruising Mexico in winter. System 5 years old and

checked to specs in SF Bay by licensed technician before leaving for Mexico. Compressor

seized in Zihuatenajo in December 2003.

Box consideration

MexicolderTM

TROPICAL YACHT REFRIGERATION

mexicolder@hotmail.com    

Handy Hints to keeping your cool in the Tropics from   Mexicolder Tropical Yacht Refrigeration Systems

Box Considerations:

1. Ideally there should be 5 to 6 inches of closed cell polyeurethane foam on all sides of the box and on the bottom. Lids can get away with 3 inches. Check around the box casing, open the galley draws, perhaps you can squeeze a couple more inches here and there. Add as much foam as possible on engine room bulkheads. A reflective outer surface will help to reduce radiant heat leaking into the box. Closing curtains or hatches to stop the sun beating on the counter top will help no end.
2. There should be good seals on the lids and front openings are a no-no for energy efficient offshore cruisers, so seal them up with silicon and don’t use them if there is a top entrance too. An easy way to improve the seal on the top is to lay a large place mat or rubber type sheeting on the counter top that can be rolled out of the way to open the box lids. This stops the moisture in humid air from reaching the evaporator and prematurely frosting it up.
3. Defrost regularly, ice on the plate is an insulator and stops the heat being efficiently removed from the box. NEVER use a sharp implement to remove ice. Transfer all food stuff to a cooler and switch off the compressor. Pour warm water on the plate and allow the ice build up to fall off. Thoroughly clean and dry the area and then after the plate is at ambient temperature switch the unit back on.
4. Extra unused box space should be filled with gallon or liter containers of fresh water, (or cases of sodas or beer) this acts as a temperature ballast. As produce and items are removed from the box replace the space with more water bottles or drinks or towels or cushions/pillows double wrapped in plastic bags. This means every time you open the box  you don’t suck in as much air at ambient temperature as you have reduced the actual amount of free air space inside.
5. Make sure the box drains are covered or fitted with a plug.
6. Hang a white piece of sheeting or canvas over the rail, immediately outboard of the box to reduce the radiant heat gain from the hull when the sun beats upon it.  
7. When you go to provision, tote a collapsable or solid cooler with you so that pre cooled meat,produce and drinks are put into the box cold.
8. A small low amp computer cooling fan mounted on top of a p.v.c. tube can be used to circulate air in the box and maintain more even temperatures. On most Danfoss compressors the fan is connected in parallel with the condenser cooling fan, but be sure the total load of both fans does not exceed 0.5 amps at 12 volts, otherwise the black contol box will be damaged. If the fans do exceed the rated load then a relay will need to be fitted. On Mexicolder units this relay is already fitted and so it is a simple job to piggy back spade connectors onto the fan terminals of the relay that sits on the double fan condenser shroud.

All these could be yours

MexicolderTM

TROPICAL YACHT REFRIGERATION

mexicolder@hotmail.com    

Life in the balance

I should point out that once you have created equalibrium in your fridge freezer you just need to keep it that way. Any warm stuff going in has to have the heat removed, plus the heat leak into the box from the ambient. Think about it like water dripping into the bilge from a leaky shaft gland. You need to pump that water out otherwise you will eventually sink. If you insulate the fridge freezer well it is akin to stopping a water leak into the bilge and thus the fridge system will have less work to do. Like the Realtor told you Location Location Location!  

With fridges it's Insuation, Insulation, Insulation!

Twenty plus years keeping stuff frozen in the Tropics

MexicolderTM

TROPICAL YACHT REFRIGERATION

mexicolder@hotmail.com    

Yeah! We all know that putting cold stuff in the fridge versus warm stuff will take less amp hours! But just how many less?

For all us amp hour concious cruisers (yes I see you constantly tilting those solar panels to get the max input) the crux for all is how do we manage to keep things frozen aboard with out having to run the main engine and or a generator. Without doubt the biggest consumer of power aboard a yacht sitting at anchor is the refrigeration system. That's why I built the Mexicolder system. I was tired of trying to find gas or diesel, haul it to the boat, listen to the noise, endure the extra heat and then have to maintain all the equipment and on top of this...PAY big bucks on a day to day, week to week, and eventually year to year basis. So with around 500 watts of solar array we now live completely off the grid. We have a freezer full of rock solid meat, fish and seafood,  can email, chat on the ham or ssb, listen to music 24/7 and enjoy the led and tube lighting on board  without a care in the world where the energy comes from.

In fine tuning our life style I always knew that the colder the product going into the box it would take less energy to make cold than hot stuff. I would shun buying ice, figuring heck I have a great fridge freezer and I can make my own which I can....but at what cost?

 Here is a simple example that can be expanded to any food or product:

Take a 6 pack of beer or soda of the truck anywhere during a Mexican summer at 90 deg. F, now I like to drink stuff at around 40 deg.F

So a 6 pack weighs 5 lbs and  90-40 = 50......this is our delta T or temperature difference between the warm and cold drink.

So 5 x 50 = 250 BRITSH THERMAL UNITS (BTU's) of heat energy you need to remove from the 6 pack.

Now if you are using solar energy to charge your batteries you will loose 10% in and out, totalling 20%, this is solar electric to chemical energy back to electrical energy. So add 20% to your 250 BTU's and you now have 300 BTU's of energy to produce using solar panels.

If you were lucky enough to find a store and purchased your beer or soda at 50 deg. F. you would only need to drop it by 10 degrees x 5 lbs and since most solar installations can make enough power when the sun shines we can almost forget about the energy loss going in and out of your battery bank.

So in short  5lbs of beer or soda dropped by 10 degrees = 50 BTU's, a sixth of the energy of the warm stuff.

So if we are doing this on solar energy alone it would mean having SIX TIMES the square area of solar panels to achieve the same result..........COLD DRINKS and rock hard frozen stuff.

If the rest of the stuff you buy is pre chilled with a bag of ice then you will save even more energy as ice is cheap and diesel and gas are not. Also bear in mind that 1 lb of ice in melting sucks 144 BTU's out of your fridge box or roughly an hour of compressor running time. You'll see that ice if and when you can find it is way cheaper than gas or diesel taking all the other costs of maintenance into account.

I rest my case