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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?

#241

Post by kevincox »

NegativeLatency wrote: post #117
Dylan16807 wrote: post #110

Earlier quoted context omitted.

Is the efficiency benefit bigger than getting a different model or taping some styrofoam to the outside of the fridge?

I’d hazard a guess that most of the losses are from when you open the door and the seal around the door. Also while cooler than ambient my fridge and freezer don’t feel cool to the touch so I think that the walls are thick enough. Otherwise fridges and freezers would ship with thicker insulation.

Putting the fridge in the basement probably leads to you opening the door less.

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

#242

Post by namibj »

nikau wrote: post #172
sjwright wrote: post #165

Earlier quoted context omitted.

It's probably a web 3.0/IoT way of saying an ESP8266 with a couple of sensors and a relay. From there you could do some slightly smart stuff like observe the rate of warming towards ambient when idle (i.e. determine the volume of material in the freezer) to determine how long you can go without running the compressor. And from there you could manipulate the thermostat's target depending on current and future predicte…

Yes, given the thermal mass of a fridge any type of advanced control is probably pointless. I think late 90s/early 2000s was the peak of fridge reliability to efficiency ratio. They run the defrost timer through the thermostat, so defrost cycles are somewhat inline with fridge use. The circuitry is simple - a defrost timer, PTC "relay", a few thermostats and the compressor. Newer fridges are a bit quieter and more ef…

Well, theoretically you could just use 3-phase motors, right? I'd actually like that, and over here in Germany, most homes have a 3-phase supply in the kitchen for an electric stovetop.

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

#243

Post by ghaff »

Gibbon1 wrote: post #223
gnopgnip wrote: post #99

Earlier quoted context omitted.

Completely saturated salty water freezes right around -6F or -21C. And most home freezers are set to right around that for energy conservation reasons, but max out even lower. So you could use any briny water and it will phase change before your food melts. I'm surprised a 12v based deep freezer that runs off a reasonably sized solar panel is not more popular/affordable. With the right amount of thermal mass, and goo…

12V/120V freezers do exist and are marketed towards RV, camping, and off grid markets. Disadvantage is they tend to be smaller, cost more. But they are very efficient. Where a residential freezer might draw a couple of hundred watts dual voltage fridges draw 25-50 watts. And automatically switch between 12VDC and 120VAC. So they can be connected to both shore power and a battery at the same time and it 'just works'

There are also propane fridges/freezers but they are also smaller. (Though at the point where you have a large propane tank, you could arguably just as well have a backup generator.)

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

#244

Post by m0nty »

MatthiasWandel wrote: post #233

Maker of the video here. For a moment, I though this was about my video and article, but reading the comments, it's more about everyone sharing their stories. Few of the comments reflect having read the article. Fair enough, sometimes it just takes a link to give theme for a discussion.

I read the article with interest. Thanks for taking the time.

My father-in-law forever refused to buy an upright freezer because "as soon as you open the door, all the cold air falls out." Which I now know to be only partially correct.

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

#245

Post by Cthulhu_ »

darkerside wrote: post #230
dctoedt wrote: post #222

Earlier quoted context omitted.

Houstonian here — did you mean Hurricane Ike (Sept. 2008)? Hurricane Igor (Sept. 2010) hit Canada, not Houston. https://en.wikipedia.org/wiki/Hurricane_Igor (In Hurricane Ike, we lost power for seven days, and ice and dry ice at the local grocery stores were rationed. We have a gas range and a gas grill in the backyard hooked to the natural-gas line. Every night for the first few nights, quite a few neighbors came ov…

That does sound nice. Unfortunate that COVID is really going to make it harder for people to pool resources like that to handle an emergency situation.

Well if anything (trying to look on the bright side here), travel beyond your own community would be limited so less risk of spreading or bringing the disease over.

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

#246

Post by Cthulhu_ »

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…

Sounds like a good idea in theory, in practice though, nowadays very few people have a house with a basement like that anymore, unfortunately. I don't get it myself to be honest, it's more efficient use of the ground surface area a house occupies.

I'd go with a chest freezer in the basement and a small fridge in the kitchen for frequently used / quick access stuff (milk, tonight's dinner ingredients).

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

#247

Post by jve »

mschuster91 wrote: post #175
jve wrote: post #131

Earlier quoted context omitted.

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 o…

Uhh, if your basement frequently gets below 0 °C, you have far bigger problems than the freezer. This should normally not happen unless you're living somewhere in the Arctic.

I have a dedicated garage with basement that is detached from home. I still have to see what temp there is in winter.

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

#248

Post by dmichulke »

Nitpick and fun fact:

"we avoid opening the fridge and freezer to keep the cold inside."

Technically, you cannot keep the cold inside because cold is a word for the absence of warmth (energy), so you're actually trying to keep the warmth outside.

Words indicating the absence of something (cold, darkness, ...) are called privatives.

h/t Terry Pratchett

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

#249

Post by Dylan16807 »

xxs wrote: post #166
NegativeLatency wrote: post #117

Earlier quoted context omitted.

I’d hazard a guess that most of the losses are from when you open the door and the seal around the door. Also while cooler than ambient my fridge and freezer don’t feel cool to the touch so I think that the walls are thick enough. Otherwise fridges and freezers would ship with thicker insulation.

if they are cooler than ambient (cool on touch) - it'd cause condensation.

Even 1-2 degrees difference can waste a lot of watts over such a big surface, and would be difficult to perceive.

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

#250

Post by [deleted] »

spuz wrote: post #238
MatthiasWandel wrote: post #233

Maker of the video here. For a moment, I though this was about my video and article, but reading the comments, it's more about everyone sharing their stories. Few of the comments reflect having read the article. Fair enough, sometimes it just takes a link to give theme for a discussion.

If I've learnt anything from reading Hacker News for a few years it's that I would take this as a compliment that the article did a good in covering any aspect we might be curious about and answer any questions we might have had. For example the fact that you did the experiment with an empty and full freezer and with empty boxes vs food pretty much preempts any nit-picks you might get from people in this this thread.

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