Small Freezer

[David]

Don't forget http://www.truckfridge.com/models.html They build 12v fridges for tractor trailers and are cheaper than the big brands. The TF49 model is very popular with the vanagon guys because it's almost a direct replacement to the factory westy fridge. I've never hear any complaints about them and they are half the price of the others.

 

[SternWake]

I seriously considered a TF 49 when My Norcold failed.

I spent $140 more for a Vitrifrigo c51is, and I do not regret it at all. Infact i believe the layout of the condenser on the VF allowed me to do modifications with the condenser fan which helped increase efficiency. the Layout of the TF-49 would not have allowed the same mods.

Either way it is 10 to 15% more efficient than my Buzzsaw Norcold with a Sawafuji Compressor was, while keeping colder interior temps..

Engel makes a fridge that is the same exact fridge as my failed Norcold. I was not impressed with the Sawafuji compressor. But that fridge was so vastly superior to maintaining a cooler with block Ice that I did not realize it was not a very good fridge, until I got my Vitrifrigo.

In terms of making Ice, to put in a cooler to keep food cool, well you'll use more electricity to make ice than a fridge would to keep the same food cool.

My Ir thermometer indicated that the interior of a cooler filled with block ice had sections which were 33f , and areas further from the block Ice that were well over 40f, and 41f is considered the threshold for food safety. When the block partially melted the difference was even worse to my surprise.

The making ice just to put into a cooler strategy, is Not going to use less battery power overall.

Block Ice sold varies in how long it lasts depending on how cold it was frozen and how long it stayed frozen. I had considerable discrepancy on how long it would last depending on where I bought it, so A 12v compressor fridge than can make ice at 28f it not going to make the same dense ice as a 120v powered freezer that has kept it frozen at -10f for weeks.

 

[Willy]

Figure I'll chip in a bit here. Having used the Engel cooler for a bit now, I can definitely notice the vibration. Part of this is due to it being solidly strapped down. It doesn't, however, change in frequency/magnitude, unlike the Danfoss in my Waeco. It also seems to cycle more frequently, but for a shorter duration, possibly due to a smaller cut in/out with the thermostat.

One thing I really like is the 'old style' mechanical thermostat. Time-tested, tough, and easy to replace. There's also NO parasitic power draw with them, unlike electronic ones, and there's basically just ONE failure mode.. which can be important when in the middle of nowhere.

It's definitely more of a 'basic' unit, having nothing in the way of low battery protection, compressor speed adjustment, readouts 'n such.. but don't really NEED all that stuff. Basically though, I'd be happy with either it, or my Waeco (or any other quality compressor style cooler). Both are proven units and can povide many years of reliable service. ..Willy.

 

[MrNoodly]

I was comparing the watt ratings and thought I saw that the mini fridge uses the same wattage as a mini freezer, so I went with the freezer.

But the main intent was to freeze as many water bottles as possible at once and quickly, to put into the cooler (instead of buying ice). Then turn off the freezer as it takes too much juice to keep it going all the time on batteries. So it was more of an ice maker unless I have shore power. Now it seems like I'm going to need 2 batteries on their own to do this with the freezer, damn.

I'm no physics genius, but it seem to me that it would take more energy to freeze jugs of water that started at ambient temperature than it does to just cool and hold food down to 40° or less (the recommended temperature to keep food properly refrigerated). And ice cools less and less as it melts and you don't know what temperature you're keeping your food at.

 

[highdesertranger]

you are correct mr n. it takes a huge amount of energy to change the temp of water just 1 degree c. I don't have the facts right in front of me and can't remember from my college chemistry classes. but if anybody doesn't believe me you can look it up, in fact I might do that and come back later with an answer. highdesertranger

 

[highdesertranger]

ok so the most understandable answer I could find. to freeze 1 liter of 20 degree c water requires 1.2 kwh of energy. this just doing the math and not taking into account inefficiency's in any given system. highdesertranger

 

[compassrose]

To find out the real energy usage for any appliance, get a Killawatt. As an alternative to ice bottles, get some Nordic Ice gel packs (or other brand). We use a mixture of Nordic Ice and frozen water bottles to keep the refrigerator and freezer temps up while we travel (we can get by with running a generator a few hours in the PM then a few hours in the AM to chill the units back down). We run with units as full as possible and artfully arrange the frozen bottles and packs to sit next to the things that need the cold the most. Remember cold air sinks and leave the door closed. Longest time without power was a little over 8 hours. I did the ice cube test to see if temps dropped on that run. I prefer to use indoor/outdoor thermometers and place the outside probe in the freezer and refrigerator with the digital thermometer stuck on the door. This way I can see the temp with out opening the door. I just have to make sure I don't have a probe sitting too close to an ice pack. Between now and next summer, I will acquire more Nordic Ice packs (replacing the frozen water bottles) to keep in the freezer. It looks like we will be having to boondock quite a bit once we hit FL and are looking for a place to buy.

The Nordic and Artic gel freezer packs are very good and much better than those blue things you buy at Wal-Mart, et al. Years ago we had some Coleman ice packs that were similar. The new ones are not as good and do not last as long. The Nordic and Artic Gel Packs are very similar or better than the old blue hardcased Coleman packs. The covers do get torn. That is why I would like to pour my leaky bags into a 20 oz soda bottle (thicker plastic bottle than the paper thin water bottles). Just need to buy the little sodas. Little bottles are easier to tuck in amongst the foodstuffs. The refrigerator ice packs get put in the freezer to refreeze. The ones in the freezer just stay there.

 

[GrayWhale]

According to the Kilawatt, this Haier Freezer kicks on at 150w.

Then immediately drops to 125w in under 1 second.

At 125w, it starts trickling down 105w at about 2-3w per second.

From 105w, it takes about 5 minutes to drop down to 92-94w where it stays until the cold level is set and shuts off (0w). I have the knob turned to its lowest setting, about 1.5 (highest is 7).

My other dorm type Haeir refrigerator ($113) with a small freezer up top is about twice the size of this 1.7 cf freezer. I recall, it runs at about this same 90ish watts. This is mainly why I got the freezer instead since they use the same amount of power.

 

[highdesertranger]

my engel uses less than 50 watts on 120v. highdesertranger

 

[Willy]

Yup, my Engel uses about 40W with 12v DC.. and that's going full blast. Have it set at 2 and that leaves most of my stuff frozen solid with the stuff (BEEEEEER!) on top liquid, but really cold. ..Willy.

 

[Spaceman Spiff]

You guys are confusing me (not hard to do)
Talking about watts used is useful, but what me and the OP need to know is how many amp-hours does a refrigerator/freezer draw in a day? This is what is depleting my battery. We are talking about 'horsepower', when what we need to know is 'gas milage'. -- Spiff

 

[Willy]

Well, there are a whole lotta variables like interior/exterior temps, insulation, amount of food, how many times opened but I'd comfortably say that my Engel, set to -2 C during the summer here, might draw 15 AH in total over a 24hr period. It rarely cycles over 30% during the day and way less in the evening. 'Course, I've added some extra insulation around it. ..Willy

 

[highdesertranger]

sorry spiff I guess that did make it a little confusing. like willy said allot depends on ambient temp. until I build my trailer and get my battery meter hooked up I won't be able to give you an exact number. I am guessing here but I would say between 15 and 20amp/hrs per day. with daytime temps in the mid 90's. I run 2 engels of 2 marine batteries and 160watts of solar with no problems. this is in the summer. in the winter I add another 65watts of solar. I brought the watts up because of grey whales post. highdesertranger

 

[akrvbob]

In the winter, my Whytner runs between 1-3 hours a day. I know that for a fact because I unplug it and it's only plugged in once a day so it can only run that much! It draws about 5 amps so it uses between 5-15 amps per day.

When I plug it in the temp usually reads at 36-39 but never more than 39, so I l let it run till it reaches 32 and it kicks off and I unplug it. The next day when I turn it on, it's about 38 again, so I repeat the procedure. On cold days, it will draw zero amps! I plug it in, the temperature is still around 35, so I just unplug it without it running at all. The next day it will be up to 39 so I let it run again.

I live in the desert between Quartzsite and Blythe, CA, we are not talking about extreme cold at all! I added extra insulation, but it is just that good a unit!

During the summer I'm sure it runs more but I'm on the go so I don't watch it or unplug it. I leave it at 38 and it's on it's own. A wild guess is it comes on 5 hours a day so it draws 25 ah? Maybe less!
Bob

 

[GrayWhale]

This is working well as a freezer, refrigerator and cooler. I have it on a timer to go on for 2.5 hours (12pm - 2:30pm) at power level "3.5" out of "7" max.

Has two, 1.5L water bottles and one, 1L that are full and are used to keep it cool when the power shuts down. There are a few small water bottles used for drinking ice cold water as it melts.

The next day, the main bottles don't melt pass 60-70%. The smaller bottles are slushy great as cold drinks. The ones with more ice, I pour warm water in for cold drinks. All the food is kept refrigerated. Ice cream wouldn't survive though. A big drawback would be food that can't take the 2.5 hours of freezer blast when it turns on.

As the weather gets colder, I'm going to drop the length that it runs and drop the power level. Or maybe set it to run for 1 hour at different intervals. If I recall, it starts up at around 100-120W and levels down to 70-72w constant....which surprisingly, is about the same as the dorm size refrigerator w/small freezer compartment; the Kill-O-Watt figures are somewhere in this thread.