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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?

#261

Post by faangFar »

an-allen wrote: post #154

Hi. Actualexperience here... it depends on the ambient temperature and how much stuff is in said freezer. So heres a data point: Freezer: normal upper level refrigerator freezer chock full of frozen fish caught on holiday in Alaska. Place, Time: Houston, TX, Late Summer, Hurricane Igor just hit and knocked our power out for 14 days. Findings: We kept the freezer shut and at about 4-5 days the fish was noticeably thaw…

USDA says to throw away everything after 4 hours.

Good ol government!

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

#262

Post by stblack »

tzs wrote: post #115
stblack wrote: post #61

I bought and filled a chest freezer in pandemic preparations. Cost of the chest freezer: CAD 1,000 Cost to completely fill the freezer with good food: CAD 2,700 Given that, during a pandemic or a winter storm in Canada, a power failure can be a prolonged event... Cost of a good gas powered generator to keep the freezer viable beyond a day: CAD 1,000. This article seems to validate the generator purchase.

I'm a little unclear on how one efficiently uses a generator to power highly intermittent loads like fridge/freezer. Does one monitor the freezer temperature, and when it starts warming start the generator, then wait for the freeze compressor stops, and then turn off the generator? Or does one keep the generator running all the time, so between times of the freezer running the generator is idling? The second option i…

Those are all valid points.

As another commenter says, the freezer isn't the only device that could be powered in an outage.

Also, in Canada, when you run a generator in a power outage, after awhile you have neighbours who appear with long extension cables. Which is fair, because the generator is noisy, and there are periods of excess capacity.

Also some neighbors will appear with gasoline because, during a power outage, you can't buy gas.

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

#263

Post by ethbro »

jsilence wrote: post #213
bryanrasmussen wrote: post #155

Earlier quoted context omitted.

Not to argue with science but why didn't you clean the fish out about day 7? Was it hurricane made getting rid of fish problematic?

'Teach a man to eat fish and he will be cold for one day...' no, wait... But seriously, why not eat BBQ fish every day?

Opening the freezer would have substantially decreased the frozen time, with each opening. Specifically as OP seemed to specify an upright freezer.

Chest freezer would have had less of an impact, but still noticeable.

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

#264

Post by hutzlibu »

an-allen wrote: post #154

Hi. Actualexperience here... it depends on the ambient temperature and how much stuff is in said freezer. So heres a data point: Freezer: normal upper level refrigerator freezer chock full of frozen fish caught on holiday in Alaska. Place, Time: Houston, TX, Late Summer, Hurricane Igor just hit and knocked our power out for 14 days. Findings: We kept the freezer shut and at about 4-5 days the fish was noticeably thaw…

" it depends on the ambient temperature and how much stuff is in said freezer."

It also depends very much on the isolation of the freezer.

And to what temperature it was set.

And of course, how often you open it.

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

#265

Post by ethbro »

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.

With proper precautions in an outdoor format, risk seems manageable. There's nothing about grilling that really requires close physical proximity.

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

#266

Post by tonyarkles »

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.

I’m laughing a bit thinking of the absurdity going on in my brain. While reading the parent comment there were two parallel streams going on in my brain:

“That is so awesome that the community rallied together like that”

“What the duck are they doing having a large gathering in their yard?! Surely they could have figured out a safer way to do that! If someone got COVID during a hurricane with no power that could be really bad!”

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

#267

Post by ethbro »

an-allen wrote: post #207
toxik wrote: post #167

Earlier quoted context omitted.

You missed the perhaps most important datapoint: how often and many times did you open the freezer? Side loaded freezer and fridges are extremely inefficient because all the cold air is let out when you open the door.

Yea so a few things he pointed out in this write up were readily observable. For example, the air falling out of the freezer is actually quite visible when hitting a hot humid ambient air. Also you could see the rate of defrosting accelerate everytime you opened the door. By the time we were able to find a gas station with dry ice we were out looking for open wal marts at a 73 mile radius from the house (Columbus Tex…

Interesting point I'd never considered until this thread...

Why not tip the freezer / fridge onto its back? So that doors open "up"?

Aware they're typically not perfectly flat on the rear face, but close enough you could support it with minimal work. And if it's unpowered, there's no need for clearance back there.

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

#268

Post by pedrocr »

gnopgnip wrote: post #99
ghaff wrote: post #28

Earlier quoted context omitted.

I'd have to do the calculations but wouldn't you be better off with a solution that just barely froze at freezer temps? Because of latent heat of melting? i.e. you want it to freeze--just at as low a temperature as possible given the freezer temperature. Your basic point makes sense to me though of course thawing isn't even. ADDED: Doing the calculation. It takes 334 joules to melt 1g of water vs. about 4 joules to r…

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…

If you're going to the trouble of doing solar it might be better to just do a small system with batteries to power other things as well like this:

https://fridge0.branchable.com/

Or go a bit higher end and put a larger solar and battery instalation with an inverter that can power the whole house. As solar panels and lithium batteries come down in cost that's becoming increasingly attractive for rural areas where the grid is flaky the best of times.

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

#269

Post by ghaff »

stblack wrote: post #256
MatthiasWandel wrote: post #237

Earlier quoted context omitted.

Problem is, freezers typically run 40% of the time. If you let it get up to -10C, the duty cycle will be a fair bit lower, but still quite high, while only drawing about 100 watts. But that's a lot of money to spend protecting food hoarding. Dry goods would be better for emergency cases.

The idea is more, if the freezer contains between CAD 1,000 and CAD 2,700 worth of food, how to keep it viable and not lose everything in a 1.75+ standard deviation power outage. The generator is insurance, not a lifeboat.

I think what parent is saying is that buying that much food "just in case" and then having to buy generator backup because you now have such an investment in that food is expensive insurance. Personally, I did buy some extra frozen food early on when grocery stores were pretty wiped out but nothing remotely like that.

What makes me periodically think about a generator is a sustained outage in freezing temperatures in winter. Given that more or less the worst that can happen in summer is I have to throw out a bunch of food, I'm not sure the generator makes sense.

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

#270

Post by HumblyTossed »

bryanrasmussen wrote: post #155
an-allen wrote: post #154

Hi. Actualexperience here... it depends on the ambient temperature and how much stuff is in said freezer. So heres a data point: Freezer: normal upper level refrigerator freezer chock full of frozen fish caught on holiday in Alaska. Place, Time: Houston, TX, Late Summer, Hurricane Igor just hit and knocked our power out for 14 days. Findings: We kept the freezer shut and at about 4-5 days the fish was noticeably thaw…

Not to argue with science but why didn't you clean the fish out about day 7? Was it hurricane made getting rid of fish problematic?

There's really not much you can do. If you take it out and throw it away, the stench will just waft back into the house because the windows are open because there's no A/C. You'll also get curious critters at night and if they knock it over and drag it across the yard, well, now you have bigger problems.

Trash doesn't run because trees and lines are down, btw.

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