Gday guys is anyone using a portable fridge/freezer as a freezer on there boat? I have set mine up as a freezer at -15 degrees .

It seems currently it runs most of the time and possibly shutting down for only about 5 to 10 minutes in every hour. It is currently empty it will be interesting to fill it and see what changes that makes. It's drawing 3.5 amps

Also I thought I might fill it with a few casks of water see if it can make solid blocks of ice I could then put into the fridge at nights and perhaps switch the fridge of at night times?

any experience much appreciated.

It works better if it's full rather than empty

I have a similiar 12v fridge which i normally turn off at night, as long as it is kept full it will stay cold enough for 8 hours or so, putting ice in it from a freezer will work, you should be able to turn the freezer off overnight too if it is fairly full and down to -15 it should stay frozen easily.
Consider adding extra insulation on the outside of the freezer,and or fridge, that will help to reduce running time and use less power. And make sure there is ventilation for the motor and compressor.

We use a Waeco CF40 as a freezer, running at about -15. I've never measured the duty cycle, but I'd guess it normally runs about 50% once it's cooled down. I'm not sure there's any benefit to turning it off at night - it will only run all the harder the next morning to catch up.

Yeah, I have a 50L Waco I use as a freezer. I also have a timer I use to shut it off at night. And I also have a 4 litre container of Glycol mix in it, that freezes at -10degC. It is one of the first things on the boat I would get rid of if I could find a solution that wouldn't cost 1000's.

Insulation is the problem. If I could fit a Luna National (or similar) fridge in where the Waco is, I be a lot better off.

As far as the timer goes, I would rater use sunlight during the day to keep it cold than stored battery energy at night. But as QldCruiser said, it just runs longer to make up the energy loss when turned back on in the morning. The only way to reduce the run time, is to reduce the energy loss by having better insulation.


Info: Glycol, (very Cheap)make you own eutectic tank. By mixing it at 3:1 you get a solution that freezes at about -10 Dec C. If the container holds a total of 4 litres then the stored latent heat (when frozen) is around 80 times what is required to change 4 litres of water just one degrees of sensible heat (sensible heat is what you read with a thermometer). Yes, 80 times.

Now pure water when frozen also stores latent heat but when it melts at Zero Deg C your frozen tucker has also (or is still in the process) melted. The benefit of using a Glycol mixture is that your tucker remains frozen because the glycol mixture is doing its latent heat transition at -10 Deg


www.seabreeze.com.au/forums/Sailing/General/How-to-improve-esky-insulation/

Southace,
I've got a cf40 portable Waeco which i run as a fridge most of the time just to keep a few beers cold. I also have 2 built in iceboxes in the cockpit which offer much more space. On longer trips I run the Waeco as a freezer, and freeze 2 litre milk jugs of water to keep the icebox cold.

Keeping the Waeco full does make it more efficient, although it will run still run most of the time until the jugs of water are frozen. My Waeco came with a zip-on insulating jacket as well. I expect it improves the efficiency.

I usually start out by freezing a bunch at home, then only need change out a couple jugs a day in the ice box while cruising.

Salt water also holds ice better than fresh

We've got a Waeco which came with a fancy dust cover which I was going to throw away because I dont like clutter on boat.

Then I read the dust cover is designed as part of the Fridges insulation and the fridge will work better with it.

So I took it out back out to boat and covered the Waeco and sure enough much less battery use. (Set to 4DegC for beer).

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HG02 said..
Salt water also holds ice better than fresh

Ahh hemm ... HG Im not sure if thats completely right ...

The heat capacity of freshwater is 4.182 J/(g K) and the heat capacity of saltwater is 3.993 J/(g K). Therefore, saltwater will heat up and melt faster than freshwater!! Not by much though.

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Trek said..

HG02 said..
Salt water also holds ice better than fresh

Ahh hemm ... HG

The heat capacity of freshwater is 4.182 J/(g K) and the heat capacity of saltwater is 3.993 J/(g K). Therefore, saltwater will heat up and cool faster than freshwater!!

Sorry My English wasn't my best subject
Salt water has a lower freezing point than fresh That was my thought but I was wrong

Pure water has a freezing point that is constant. It is 32 degrees Fahrenheit. When a substance is added to the water, it does two things.Lowers the freezing temperature of water Varies the freezing temperature of water - this is why the melting rate of water sprinkled with sugar is different from the melting rate of water sprinkled with saltIn both cases, the temperature is lowered, which is why salt is put on roads during freezing temperatures. It means the water on the road will not freeze, even though the air temperature is cold enough.The chemical nature of the substance that is put on ice, however, is not an important factor. Instead, the number of molecules determines how fast or slow the ice melts. This is known as a colligative property.Assume there is the same measurement of salt and sugar - one tablespoon. There are more molecules in the tablespoon of salt than there are in the tablespoon of sugar. This is why the tablespoon of salt melts ice faster than the tablespoon of sugar.

When buying ice years ago Id take it home and put it in the freezer over night to bring the temp down as most retail outlets just have the ice temp set at freezing piont

Had good results putting a layer of newspaper over the top of food when running a fridge as a freezer, makes good insulation and you can use it between layer to reduce loss of cold to lower items when opening the freezer.

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I used to stuff news paper down my past on a winters night ride from the West coast of Tassy to Launceston years ago

Found this today while googling Engels 30 liter draw fridge be a good weekender
http://www.engelaustralia.com.au/2products_details.asp?pid=22&productid=21648




<div>New Compact Sawafuji Swing Motor

<div>Steel Cabinet

<div>Solid Construction

<div>Stainless Steel Runners

<div>Internal LED light

<div>Built in Ventilation with dual fans

<div>Auto Switching 12 - 24 Volt DC

<div>Power consumption 2.7 Amps (12 Volt) 1.5 Amps (24 Volt)

<div>Compressor unit can be remotely located up to 1.5 Metres away

<div>Dimensions:

<div>Overall (including door and compressor) L716 W440 H250mm

<div>Cabinet only: L525 W440 H250mm (compressor mounted remote)

<div>Hardware supplied includes;

<div>4 x right angled brackets and screws

<div>Wiring extension loom for remote compressor mounting
Capacity:30 Litre (35 x 375ml cans)

I love the idea of layers of newspaper hmmm steaks,pork chops, lamb, roasts, mince should keep me going for 3 weeks or so on the pick over Christmas! dunno about the draw fridge ho2 that would loose a lot of cold air once you pull it out and select what you want!

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southace said..
I love the idea of layers of newspaper hmmm steaks,pork chops, lamb, roasts, mince should keep me going for 3 weeks or so on the pick over Christmas! dunno about the draw fridge ho2 that would loose a lot of cold air once you pull it out and select what you want!

That's what i thought to .
But as a weekend fridge as long as you didn't open frequently would be OK and you could also wrap more insulation around it
Id rather make ice and use a good Esky in the cockpit no matter what fridge you have on board get what you want out of it quickly and close it up asap.

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southace said..
I love the idea of layers of newspaper hmmm steaks,pork chops, lamb, roasts, mince should keep me going for 3 weeks or so on the pick over Christmas! dunno about the draw fridge ho2 that would loose a lot of cold air once you pull it out and select what you want!

I have Vitrifrigo draw fridges and freezers in both my boat and caravan. They are extremely efficient and hold a lot more than a normal door fridge. We were so impressed with the ones in the boat, we ordered the same fridge and freezer to be installed in our new caravan. The draws hold the cold air similar to an open top fridge in the supermarket. Chest fridges hold the air better but you generally need to pull every thing out to get what you want. In our previous boat it had a chest freezer and my wife could not reach the bottom with out falling in. We were sceptical of the draw fridges when we ordered the boat but now we would have nothing else.

I love those draw fridges. Was gonna buy one but at 800 for the engel draw i thought id get the waeco. I love the waeco but thise draw fridges seem practical and would use less space.

A fridge/freezer is more efficient at night when the ambient temperature is lower. However, if you are using battery power, that is less efficient than drawing straight off your solar or wind source. So switchng off at night probably depends on how much generation capacity you have.

The biggest load is actually freezing the food, so if it can be frozen at home or bought frozen that will make the most difference.

G'day ACE. First post as a Seabreeze member.
I suspect that I'm reasonably competent to contribute having been on the hook 24x7 for over 7 years now.
Six years ago I bought my first fridge, a Waeco CF18. (mistake based on dollars). The bottom of it rusted out within about a year causing water to drip out
onto the electrical components. I only used as a fridge and it drew 3.75 amps and it cycled at about 50% rate (running 12 hours per 24 hour period.
So I bought another Waeco CF18.....same story about 14 months later. But in the last 8 months of it's life I cranked it up to -15 freeze mode.
Then I bought an Engel 38L Eclipse with the insulated protector cover. The Engel too cycles @ about 50% duty cycle but it draws an Amp less.
Now, over three years later, the Engel hasn't missed a beat and I lift the (full of food) basket out about every 12 months for a ten minute defrost'
FWIW, my battery capacity is 480AH as a single bank.
Hope this was useful.
Cheers Brian

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brianlara3 said..
G'day ACE. First post as a Seabreeze member.
I suspect that I'm reasonably competent to contribute having been on the hook 24x7 for over 7 years now.
Six years ago I bought my first fridge, a Waeco CF18. (mistake based on dollars). The bottom of it rusted out within about a year causing water to drip out
onto the electrical components. I only used as a fridge and it drew 3.75 amps and it cycled at about 50% rate (running 12 hours per 24 hour period.
So I bought another Waeco CF18.....same story about 14 months later. But in the last 8 months of it's life I cranked it up to -15 freeze mode.
Then I bought an Engel 38L Eclipse with the insulated protector cover. The Engel too cycles @ about 50% duty cycle but it draws an Amp less.
Now, over three years later, the Engel hasn't missed a beat and I lift the (full of food) basket out about every 12 months for a ten minute defrost'
FWIW, my battery capacity is 480AH as a single bank.
Hope this was useful.
Cheers Brian

The Engel 38lt Eclipse is a top fridge for a boat for all the reasons Brian has said. The Eclipse is better than other Engel models for boats because of its pvc casing that does not rust. I have one in my front sail loft that I use to keep bait and any other smelly things that the wife will not let me put in the boats draw fridges. We also use it to freeze down any fish we catch.

Some great experience thanks guys.

so currently my freezer is running from -15 down to -13 every 10 minutes at 3.4 amps while empty.

i will attempt to stock it over the next 2 months starting with 2 litre milk bottles then layers of meat and newspaper.

hopefully this will change my run times to -15 down to -13 every 30 minutes at 3.4 amps while full this should be 50% run time?

So 50% should be 12 hours X 3.4 amps = 40.8 amps over a 24 hour period.

So my fridge and freezer should draw approx 80 to 100 amps in a 24 hour period.

With approx 15amph X 8 = 120 amp solar input over a 8 hour period I should only just get by!

Perhaps I should give up eating meat and just eat fish!

King George whiting.

What about freezing down some milk bottles with a strong brine solution inside like the "bricks" we used to use.

Na me and Cat drink a lot of milk and it's only $2 a bottle at Coles! :)

Loading up a freezer does not significantly change the power draw, provided what you put in is already frozen. What it does change is the cycle time- runs for longer, and off for longer.

If you want to reduce current/energy consumption, reducing the times the door is open, and adding insulation, is the way to go.

Something I forgot to mention. As I said, when i bought my Engel i also purchased the Engel padded insulation/transit protection bag/cover.
The bag is a verv good piece of kit and the top of it closes with velcro.
Now, because it is a pretty sloppy fit I found that was able to slide 30mm closed cell foam sheets into the air gap. On my freezer the front, back and end faces have the foam jammed into place and so effectively I thickened the freezer walls by 30mm and the 70 year old motor mechanic/ auto electrician in me figures the the foam must be a definate way of insulating the food.
The foam I used was cut from sheets i bought from Whitworths as item #31039 which is 1320mm x 325 x 30.
Its a tight fit but it is there! "there" being the operative word.
Even if your fridge/freezer available for it, and my old Waeco CF 18's didn't, simply use pvc cement to bond the 30mm panels to those faces, eg lid etc, which dont have condenser outlets etc.
On my old Waecos the wall thickness was way less than the 30mm addition I gave them.
Don't know why I forgot to mention it and why nobody else has. As i see it the foam weighs nothing, takes up vittle space and MUST save heaps of power. (though I've never measured the difference. For me it was the best $40 Ive ever spent)
Consuming 5 amps for every hour my TV is running I simply must minimise my freezer consumption.
Sorry it was a rant....
Brian.

I just read my last post.....big omission!
Meant to say, 'even if your present fridge doesn't have a transit bag available for it'.
Sorry.

I've a couple of Engel 40 ltr drop ins which I still need to add insulation in to but will in the coming months
So far am happy with them and the options of fridge freezer hoping will suit my needs

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Yara said..
Loading up a freezer does not significantly change the power draw, provided what you put in is already frozen. What it does change is the cycle time- runs for longer, and off for longer.

If you want to reduce current/energy consumption, reducing the times the door is open, and adding insulation, is the way to go.

Won't the run time be reduced and the off time increase once I have my freezer full of frozen milk, icecream and Meat?

if my freezer is -15 on shore power for the next couple of months surly everything I put into will freeze with out having to freeze it first?

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southace said..

Yara said..
Loading up a freezer does not significantly change the power draw, provided what you put in is already frozen. What it does change is the cycle time- runs for longer, and off for longer.

If you want to reduce current/energy consumption, reducing the times the door is open, and adding insulation, is the way to go.

Won't the run time be reduced and the off time increase once I have my freezer full of frozen milk, icecream and Meat?

if my freezer is -15 on shore power for the next couple of months surly everything I put into will freeze with out having to freeze it first?

Exactly Ace. I try to keep my freezer full which means going to the supermarker about weekly. What I buy is never frozen, just meats and lasagnes etc out of the fridge. By next morning everything I put in the day before is down to c. -13 or so. When I measure I use an Infrared gun. (only ever temp tested a few times in the early days because the system works). I find that products like 'stuffed chicken (quinoa/cheese) roasts' definately do NOT keep like red meats or fish do. Er, error. I DO also buy Birdseye vegies etc which are still pretty frozen by the time I eventually back to the boat.

I might also connect a computer fan directed over the compressor wired into my solar. I have noticed a massive diference when I run the fridge computer fan or open the sink door where the fridge compressor located.

Thanks for the replys guys I will keep you posted how it goes.

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southace said..
I might also connect a computer fan directed over the compressor wired into my solar. I have noticed a massive diference when I run the fridge computer fan or open the sink door where the fridge compressor located.

Thanks for the replys guys I will keep you posted how it goes.

Yes the extra fan, keeping the condensor cooler will help immensely. Almost no extra current draw. I took the fan out of my first Waeco and piggy backed it to the outside of the second Waeco as a suction device to assist the inner fans extraction thru the plastic grill.
How lucky you are to have shore power. I run my genny (running a Sterling 12/60 charger) for two hours per day.

+1 for the Engel 38lt Eclipse. Low power usage & quiet. We use it only as a fridge, but it has done service as a freezer, although not intentionally.

I will need to remove it soon as it currently sits in the quarter berth and the space needs to revert to a berth for an upcoming trip. The Engel just doesn't fit anywhere else, so I plan to remodel the existing eutectic fridge / icebox into a smaller version of itself with a new eutectic plate. If I could find a new spot for the Engel it would solve all my problems.