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How long does a freezer stay frozen when the power goes out?

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Re: How long does a freezer stay frozen when the power goes out?

#131

Post by jve »

morninglight wrote: post #64

The location of the freezer or refrigerator is critical. If you live in a house that has a typical unfinished basement, don't overlook the advantage it offers. With one simple change, you can noticeably lower your electric bill, reduce your carbon footprint, gain extra kitchen space and improve your health. Just move your refrigerator to the basement. Since the basement is normally cooler than the upstairs, the refri…

From what i'v read, freezers are designed to be placed in ambient temperature greater than +10C.

There are specificially designed freezers that can withstand up to -15C ambient temp: https://home.liebherr.com/en/lva/products/household-applianc...

A guy on the phone that sells used freezers told me that compressor has some liquid that gets thicker when temperature drops below X and compressor has to work harder.

The other reason i'v read somewhere is related to compressor not maintaining stable temperature, won't turn on when needed etc.

These may be false statements and I ask for some guidance from professionals - is that the case? I understand when temp may fall below 0, you need some special freezer. Liebherr guy assured me any of their freezers will work OK as long as it is > 0C. But he couldn't tell about other manufacturer freezers.

As i'm in the process of buying a freezer that has to work in basement, could someone chime in please? Is Liebherr my only option?

Re: How long does a freezer stay frozen when the power goes out?

#132

Post by supernova87a »

I was just looking at getting a NG generator installed for my parents on the east coast, after watching these recent storms come through. I'd dawdled on this for years, because it was just infrequent enough.

Anyway, I also looked at battery backup systems (Tesla, Enphase, etc). Unfortunately, it seems they haven't reached cost competitiveness with the plain old gas generator yet. Not a lot of power density (time), and too expensive for the benefit in noise/fumes/etc. $15000 for 2-3 days worth of backup, compared to $5000 for installing a Kohler run of the mill NG unit, etc.

I was disappointed -- was hoping that batteries were further along than they are. Anyway, I'm sure there's going to be a run on getting these installed for the next few months, so clearly there's plenty of time to think it over.

Re: How long does a freezer stay frozen when the power goes out?

#133

Post by wutwutwutwut »

efficax wrote: post #122
wutwutwutwut wrote: post #109

Earlier quoted context omitted.

What kind of stoves do you guys use where this is a risk? Guessing it's not induction?

in the US natural gas stoves are very common. There is some risk when frying on high heat that you could start an oil fire... Never used induction but gas offers very fine control of heat with a nice stove, especially compared to electric which relies on radiant heat from a coil and cannot change temperatures rapidly

Inductions are electric and does not have the issues you mention. But I see. For some reason natural gas didn't pop up in my head. Where I live nobody use those.

Re: How long does a freezer stay frozen when the power goes out?

#134

Post by BrandoElFollito »

efficax wrote: post #122
wutwutwutwut wrote: post #109

Earlier quoted context omitted.

What kind of stoves do you guys use where this is a risk? Guessing it's not induction?

in the US natural gas stoves are very common. There is some risk when frying on high heat that you could start an oil fire... Never used induction but gas offers very fine control of heat with a nice stove, especially compared to electric which relies on radiant heat from a coil and cannot change temperatures rapidly

I used gas for 20 years, then induction for 10.

Induction wins everywhere (reproducibility of heat, speed to heat, ease of cleaning...)

The only thing I miss a tiny bit from gas is the ability to tilt a pan to have oil gather in a puddle to deep fry something small.

Other than that everytime I use gas I long for induction.

Re: How long does a freezer stay frozen when the power goes out?

#135

Post by rollulus »

galkk wrote: post #112

> When opening an empty upright freezer, all the cold air can just "fall out" I recently found that the ice-cream refrigerators of street vendors (and everything else that is being sold when the doors are frequently opened) are opening on the top for that exact reason - to not let cold air "fall out" (because cold air is on the bottom)

I find it weird that his new freezer has open compartments. Mine, and the majority a quick google search showed, have boxes with the opening on top in each compartment, you can slide out. I don't have the numbers but my intuition says that it's more energy efficient.

Re: How long does a freezer stay frozen when the power goes out?

#136

Post by thaumasiotes »

teej wrote: post #29
dpeck wrote: post #27

Earlier quoted context omitted.

Freeze cup of water with some red food coloring in it. Turn upside down. If you ever come back to a freezer that looks like it’s covered in frozen blood you’ll know.

I always heard this as an upright cup of frozen water with a penny on top. If you come home and the penny is inside the ice you know the freezer went out.

I think it bears mentioning here that you need to choose a cup that can survive the expansion of its contents. Or in other words, not a glass cup.

Re: How long does a freezer stay frozen when the power goes out?

#137

Post by masklinn »

Someone1234 wrote: post #10
at_a_remove wrote: post #8

Personally, I throw blocks of dry ice in there as soon as the power has been out a few hours, just in case. Beats regular ice all the way.

How do you safely handle dry ice? I'm legitimately asking, I know retailers sell it with big warning labels but I wouldn't know how to transport it, move it, and similar.

Dry ice is really easy to handle. If you don't swallow it, the main danger is letting it sublimate in an enclosed space as that'll fill said space with CO2, but we are very sensitive to CO2 levels (unlike CO or N2) so the danger is low there, just don't be a complete moron.

Seriously, dry ice sublimates so when you hold a block or pieces unless you actually grip the thing, the layer of sublimating CO2 protects your hand rather well. Use gloves or tools if you're going to move large amounts (e.g. dozens of blocks by hand, or pellets by the literal fistful) both to protect your hand and to avoid wasting your dry ice more than necessary.

But as far as "dangerous" things go, dry ice is really low on the scale.

The biggest danger is putting too much in a completely sealed and locked environment as the sublimation will cause significant expansion, increase in pressure, and therefore a possible explosion.

Re: How long does a freezer stay frozen when the power goes out?

#138

Post by thaumasiotes »

at_a_remove wrote: post #53
Someone1234 wrote: post #10

Earlier quoted context omitted.

How do you safely handle dry ice? I'm legitimately asking, I know retailers sell it with big warning labels but I wouldn't know how to transport it, move it, and similar.

I've handled it for decades. First thing you do when you get your slab is that you wrap it in two towels, then you fold down the loose edges and pop that in a cooler. Towels towels towels, that's my go-to. You can handle dry ice with your bare hands -- I have scores of times -- the trick is that contact with pressure (squeezing or weight) is what is going to give you frostbite. Otherwise, I have swiftly moved two pou…

> Now, if you're feeling fearful, you can drive with the windows down, but to be honest, carbon dioxide in too high of quantities will invoke a gasping/coughing reflex. You would have plenty of warning. You can verify this by putting a small chunk of dry ice in water, leaning over the cup, and inhaling. You'll cough, and that is the reflex to look for.

The mechanisms that regulate your breathing use carbon dioxide levels as their only input. One side effect of this is that you'll happily suffocate to death, never realizing anything is wrong, breathing a gas that contains no oxygen -- as long as it also contains no carbon dioxide.

A happier side effect is that you will definitely detect, and feel very unhappy about, inappropriately high levels of carbon dioxide.

Re: How long does a freezer stay frozen when the power goes out?

#139

Post by Xylakant »

dantillberg wrote: post #49
aaron695 wrote: post #46

Earlier quoted context omitted.

You'd be better off having lidded containers with no water. Since it stops the air loss every time it's opened. But you don't lose the energy when you take them out. Water is ~ 1000 times heaver than air so for a fridge, removing the water is the same as letting out air 1000 times. Freezer is worse because there is also the phase change in the water. But having ice is useful.

It depends what you're optimizing for. If you're primarily interested in resilience to power outages, then maybe you are OK with the wasted energy used to freeze/re-freeze the extra water.

Water is not a good choice to optimize for this. Most energy from the ambient air gets consumed at the thawing point of the medium - 0 degrees for water. So water/ice will keep freezer at 0 degrees for longer, but that’s not an attractive goal for a freezer - you want some cooling medium that does the phase change at a colder temperature (adding copious amounts of salt to the water would go a long way)

Professional cooler packs can have that point down as far as -35 Celsius.

Re: How long does a freezer stay frozen when the power goes out?

#140

Post by thaumasiotes »

heelix wrote: post #50
Someone1234 wrote: post #10

Earlier quoted context omitted.

How do you safely handle dry ice? I'm legitimately asking, I know retailers sell it with big warning labels but I wouldn't know how to transport it, move it, and similar.

It is not super dangerous stuff. You can (and should not) juggle it bare handed briefly without ill effect. One thing to consider is dry ice is frozen CO2. Camping, it was a clever way to pack in our steaks without having a watery mess. What we figured out, was the mosquitos are attracted to CO2. The poor guy with the food pack had a cloud of blood suckers around him every portage. A normal cooler works fine. Somethi…

> What we figured out, was the mosquitos are attracted to CO2.

Yes, unfortunately, the usual meaning of a concentration of CO2 is that there's an animal nearby exhaling it.

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