How does a chest freezer work?

Elliot · Post by **Elliot** » Fri Jun 18, 2010 9:48 am

I just scored a free chest freezer. It says 2.8 Amps, so that's only around 300 Watts, right? Piece of cake for either of my Honda EU gennys.

But I would rather not have any genny running 24/7.

This freezer cooled down from 60 F to Minus 10 F in two hours. Very impressive. So... once it is cold, and the contents are cold, it should not need to run very long at the time to maintain cold.

I figure that if I insulate and shade the freezer well enough, I can get away with running the genny manually for a short time just a few times a day. But how to add insulation to the thing? It says "FREE STANDING OPERATION ONLY" on it. That makes sense -- the heat needs to get out somewhere. But where does the heat get out?

On a refrigerator, there is a heat-exchanger coil on the back. This coil must not be covered, or even be too dusty, because that's where the heat gets out. But I see no such coil on the freezer. (I looked under it too.) All I see is the compressor, which sits by itself in a corner cubby-hole, exposed to the outside.

When all the air inside this thing changed from 60 F to Minus 10 F in two hours, what path did all that heat follow out of the thing???

Yes, ice cream. Lots of ice cream. Ice cream ALL week. At Kinetic Cab Company.

Post by **Sham** » Fri Jun 18, 2010 9:54 am

What you can do is lay a big moving blanket over the top of it to provide further insulation and trap in the cold. You mentioned the shade already. Depending on the heat, you could do one hour on, three hours off. Nightime you could do a lot less, especially if the air is cold. I would keep the blanket on at night as well.

I would definately run the freezer on the generator ahead of time. I am pretty sure that a freezer uses about 1000 watts of power when the compressor is running. This is regulated by a thermostat. Also, is this an older freezer or a new energy efficient one? Big difference in power consumption.

mudpuppy000 · Post by **mudpuppy000** » Fri Jun 18, 2010 10:03 am

I haven't actually tried it myself but I heard that things will stay cooler if you keep them up off the ground also.

FIGJAM · Post by **FIGJAM** » Fri Jun 18, 2010 10:35 am

And a full freezer is more efficient than one not completely full, so fill the space with water jugs.

Bounce530 · Post by **Bounce530** » Fri Jun 18, 2010 10:40 am

We've had a chest freezer out there and ran it off a cheapy h/f genny. The genny had to run alot. We could get away with it not running for a couple hours here and there, but did have to run it alot. The freezer was covered with blankets, and stayed in the van all week. The van doors were kept open most all week also.

Elliot · Post by **Elliot** » Fri Jun 18, 2010 11:14 am

On the label it says "DATE: 9412". I'm guessing that means December 1994.

More important, I suspect, is the "AMPS: 2.8". Sometimes I wonder if I'm old enough already to forget stuff I learned as a child, but... Volts x Amps = Watts, right? So 115 V x 2.8 A = 322 Watts? I have a 1000 Watt genny and a 3000 Watt genny to choose from.

Yes, blankets over it, but I'm thinking styrofoam around it also, to maximize the time between generator runs. That's where I might get in trouble.

I'm puzzled that these things don't have a thermometer on them. Bet I can install one, though.

What it does have, is a monitoring system that -- I believe -- sets off a buzzer if it warms up too much. There is a switch to test the buzzer, and that system seems to work. But not if there is no power to it!

Yes, I will definitely run this combination at home and get it "dialed in".

FIGJAM · Post by **FIGJAM** » Fri Jun 18, 2010 11:50 am

Keeping the extra room packed with ice jugs will cut down on your genny runtime. Ive always kept the freezer full. when we have a 6 or 8 hr. power outage nothing even gets close to defrosting even a little.

Token · Post by **Token** » Fri Jun 18, 2010 12:09 pm

Didn't we talk this out earlier this year?

You cannot add insulation easily to a chest freezer. The whole external metal shell has coils pressed into it and dissipates the heat. The interior box is the evaporator, again pressed into the whole surface. The insullatio is in between.

The only place you can add insulation is the lid. It is worth the effort snce it is simple and does help with the cooling.

DO NOT insulate the sides.

Chest freezers are already very efficient. This is why they have small motors and such. They are good at keeping frozen things frozen but not as good at freezing things from room temperature. They operate best when there is a large mass of frozen stuff already in there.

Having said all that technical stuff here is what I do when driving up.

I pack the freezer with frozen stuff the night before I leave. I make sure there is a few inches of room around the freezer. Overnight I run house power to it.

Just before leaving I disconnect power and wrap everything in a thick blanket.

On the two rest stops I take, I pull the blanket off and plug in my EU1000 for the duration of the break (1/2 hour).

Ecerything stays pretty much frozen for the 15 hour drive.

You could probably do this on playa as well. Run max cold for an hour or two then cover with a thick comforter once the sides cool off. I would Taylor the cover so it's snugg and also put box on a pallet with a blanket on it.

You'll probably need to run juice twice a day or so.

Get a thermometer with an alarm to avoid a disaster.

Elliot · Post by **Elliot** » Fri Jun 18, 2010 12:45 pm

The whole external metal shell has coils pressed into it and dissipates the heat. The interior box is the evaporator, again pressed into the whole surface.

Token, you are my hero! That is the information I needed! Mystery solved!

Piece of cake from here on in. Uh... make that bowl of ice cream. Ice cream for everybody -- come-n-gettit!

Captain Goddammit · Post by **Captain Goddammit** » Fri Jun 18, 2010 8:05 pm

Hey Elliot, that freezer's running power draw might be 300 - 400 watts, but it's STARTING power draw is gonna be a lot more! You'll probably need the 3000-watt genny.

Elliot · Post by **Elliot** » Fri Jun 18, 2010 8:18 pm

Yes, electric motors always draw a lot more at start-up. And I am indeed planning to use the EU3000 for this. Thanks for the reminder!

Token · Post by **Token** » Fri Jun 18, 2010 9:06 pm

C'mon guys, it's a chest freezer not an electic train.

I ran a 8 qft and 13 qft box at home off the EU1000 when the transformer blew on the block.

In 2008 we ran a 24" regular fridge and the 8 qft on Playa for three weeks off the same EU1000.

It can take it.

The specs on the box are maximum draw which is mandated by UL. Electrical fire safety and all that. Must list max to limit liability. Thing probably runs 150W after the startup peak.

motskyroonmatick · Post by **motskyroonmatick** » Fri Jun 18, 2010 9:08 pm

What happened to all those auto start generators that were being sold to contractors 10 or 15 years ago? It worked like.. Pull trigger switch on skill saw and generator starts. Shuts off a little while after power is not needed. I swear this was a widely advertised or sold item.... That would be super if it worked with intermittent demand units like freezers.

Elliot · Post by **Elliot** » Sat Jun 19, 2010 8:37 am

Token: Now you are my DOUBLE HERO!

Motskyroonmatick: Such an auto start feature is what I was looking for around here earlier, but all I found was remote control start. What we want for this purpuse might perhaps best be called "on demand start".

We're making serious progress here!

Token · Post by **Token** » Sat Jun 19, 2010 9:22 am

Call Hayes and see if they have a solution.

http://www.hayesequipment.com/

They have a wireless remote kit for the EU3000 complete with auto choke gizmo. They manufacture the box so may have a geek or two that can help with a mod for thermal trigger.

Not too pricey either at $160.

theCryptofishist · Post by **theCryptofishist** » Sat Jun 19, 2010 10:45 am

All I know is that when the chest freezes the nipples come out.

Elliot · Post by **Elliot** » Mon Jun 21, 2010 8:28 am

Hayes replied to my e-mail very quickly. But the answer was "Sorry".

I think if I install a thermometer and keep an eye on that, I can probably run the genny as needed manually. And that will let me use the EU1000 instead of the 3000.

So now I'm looking for a thermometer with the sensor on the end of a wire or thin tube, so I can read the temperature without opening the lid.

FaeTora · Post by **FaeTora** » Mon Jun 21, 2010 8:32 am

I know its meant to check the tempature of meat in the grill without opening the lid and don't know if it will work for you for this purpose, but there are wireless digital ones. They should be ale to read down to 0 because its digital but I can check on it today when I go in. Don't know if it will work but it might be worth a shot.

ygmir · Post by **ygmir** » Mon Jun 21, 2010 8:33 am

Elliot wrote:Hayes replied to my e-mail very quickly. But the answer was "Sorry".

I think if I install a thermometer and keep an eye on that, I can probably run the genny as needed manually. And that will let me use the EU1000 instead of the 3000.

So now I'm looking for a thermometer with the sensor on the end of a wire or thin tube, so I can read the temperature without opening the lid.

those indoor/outdoor thermometers have a super thin wire, or, remote.
That should work great.......

Remember, chest freezers aren't "quick recovery".....in that, they are made to run mostly 24/7 and cool long term, low energy.........

Elliot · Post by **Elliot** » Mon Jun 21, 2010 10:45 am

Those indoor/outdoor thermometers have a super thin wire, or, remote.

Do you mean that these are common hardware store items? That would be fabulous!

Right -- I'll have the freezer loaded and max-frozen before I leave home. But I WAS impressed that it went from 60F to -10F in two hours (empty).

ygmir · Post by **ygmir** » Mon Jun 21, 2010 10:50 am

Elliot wrote:
Those indoor/outdoor thermometers have a super thin wire, or, remote.
Do you mean that these are common hardware store items? That would be fabulous!

Right -- I'll have the freezer loaded and max-frozen before I leave home. But I WAS impressed that it went from 60F to -10F in two hours (empty).

yup, hardware store, for sure.......

that is good recovery........but, seems it might be way slower, if filled with stuff..........all the mass within will have to lose it's heat, and, that might take time........also, depending on how tightly it's stacked, I'd think.

Risky · Post by **Risky** » Mon Jun 21, 2010 11:10 am

Elliot - I brought out a chest freezer last year and kept it out of the sun.
I only had to run it about 4hrs a day, during the hottest part.
No additional insulation needed.

On the way to the playa, I used dry ice.
Once I got to the playa and plugged in, I gave away the dry ice.

Filled it full on the last ice day and never needed to plug it in again.
Crushed ice stayed frozen until I went home on Wed night.

It is a playa necessity for me, now.
I store food for the camp kitchen for late in the week, ice cream, etc.
Also having ice available before and after event ice sales.
Nothing like having coffee ice ice cream about 2 in the afternoon.

Elliot · Post by **Elliot** » Mon Jun 21, 2010 11:25 am

Ygmir:
It will get loaded with well-frozen ice cream, frozen pizzas, jugs of frozen water, and what-not-else that's already frozen, so it will never need to freeze anything on its own.

Except, probably some water jugs that have melted while being used in portable ice chests. But that would be minor.

Risky:
That sounds encouraging. I can manage to remember to run the EU1000 four hours a day. And Ygmir's thermometer will teach me how.

There shall be ice cream!

Elliot · Post by **Elliot** » Mon Jun 21, 2010 4:54 pm

This looks like a suitable thermometer:

http://www.google.com/products/catalog? ... CDEQ8wIwAA#

15 bucks and none of that newfangled RF or other "magic" signal transmission.

ygmir · Post by **ygmir** » Mon Jun 21, 2010 5:03 pm

that looks perfect, Elliot.

Risky:
where did you get your freezer?

motskyroonmatick · Post by **motskyroonmatick** » Mon Jun 21, 2010 5:04 pm

My search for auto starting generators did not yield anything productive. It is possible for around 300 bucks to make virtually any onan rv generator self starting based on a number of factors. 300 bucks buys allot of gas.

Risky · Post by **Risky** » Mon Jun 21, 2010 5:11 pm

ygmir - I had to find one small enough to fit inside my 62 Winnebago doorway for transport. Malwart for about a buck twenty five.

Elliot · Post by **Elliot** » Mon Jun 21, 2010 6:12 pm

motskyroonmatick wrote:My search for auto starting generators did not yield anything productive. It is possible for around 300 bucks to make virtually any onan rv generator self starting based on a number of factors. 300 bucks buys allot of gas.

Thanks for taking the time to search for me!
Refrigerated 18-wheeler trailers have just what I'm looking for. I know that for a fact, because of the gazillion times I have been awakened in the middle of the night by those! But outside my budget, yes.
This $15 thermometer and my EU1000 will do the job fine.

Post by **Elderberry** » Mon Jun 21, 2010 6:37 pm

Don't forget that the higher up you are the less power your generator will generate.We learned that the hard way.

JK

ygmir · Post by **ygmir** » Mon Jun 21, 2010 6:44 pm

Elliot wrote:
motskyroonmatick wrote:My search for auto starting generators did not yield anything productive. It is possible for around 300 bucks to make virtually any onan rv generator self starting based on a number of factors. 300 bucks buys allot of gas.
Thanks for taking the time to search for me!
Refrigerated 18-wheeler trailers have just what I'm looking for. I know that for a fact, because of the gazillion times I have been awakened in the middle of the night by those! But outside my budget, yes.
This $15 thermometer and my EU1000 will do the job fine.

you may want to check the amperage required to run, and mostly, start the motor on said freezer........as relates to the 1KW rating of the generator.
it takes twice the amperage to start a motor as to run it.

just a thought.