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

woodgears.ca

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

#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.

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

#62

If you can restock the freezer with ice, you can keep it cold for several days easily. Spoken from experience, thanks PG&E.

Where do you get ice if you are out of power?

Sometimes you know in advance that power will be off, so you can freeze extra. Or buy outside.

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

#63
post #29
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.

That is a much cleaner method

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

#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 refrigerator will run less often. This will not only extend its lifetime, but also lower the electricity it consumes, thus also reducing your carbon footprint. The kitchen space previously wasted by the refrigerator has uses that are only limited by your imagination.

Finally, you and your family will directly benefit from the exercise you get with trips to the fridge. Of course it is not convenient - that is the point. Sometimes you might even pass up that extra dish of ice cream, because it's a pain in the butt. However, the size of your butt may be improved.

It's a simple step that can be done in a couple of hours. And the recurring benefits are automatic and last a lifetime.

Method #1: https://www.youtube.com/watch?v=2J8ul-CcrzY

Method #2: https://www.youtube.com/watch?v=NXCiWk-aIyc

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

#65

If you can restock the freezer with ice, you can keep it cold for several days easily. Spoken from experience, thanks PG&E.

Where do you get ice if you are out of power?

This depends entirely on one's situation. I could easily get as much ice as I wanted from a nearby river, should the need arise during winter time. During summers, it'd be pretty much impossible to get hold of sufficient quantities.

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

#66
post #13

Earlier quoted context omitted.

You’re not wrong, but at that point it’s basically just an ice chest—a bunch of ice will keep perishables cold, whether it’s in a fridge or a portable cooler or whatever. Not as efficient, maybe, but a modern fridge is already quite efficient at retaining coolness, so I don’t see why this isn’t a permanent solution!

I actually went through this last week. The problem is that, if the power goes out (presumably without advance warning), a bunch of triage to basically turn your freezer into a cooler for critical items is going to cost a bunch of the stored cold air. I'd probably go instead, if you have a cooler, with buying a few bags of ice if you can and quickly pulling out high value/especially perishable items and putting them…

You don't have to be so quick about it. The heat capacity from warm air coming inside is dwarfed by that of the frozen solids and especially their latent heat absorbed during the melting process.

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

#67
post #18

A test with the freezer as full as possible with just water would be interesting as a best-case set of data points to compare against. I always keep containers full of water in the bowels of my refrigerators/freezers only removing them when the space is required for food. There's not much sense in keeping empty volumes of air in a refrigerated space.

I don't understand why that doesn't make sense. What you do with containers of water is what doesn't make sense to me.

Google 'icebox', which is coincidentally what my Dad still calls refrigerators. Different times.

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

#69
Here's what I've learned about refrigerators recently.

My fridge is failing in a revealing way. It has an automatic defrost unit- this means that it heats the evaporator coils in the freezer every so often (I think it's once every 36 hours) to melt the frost off of them, producing the same condensation you normally get from an A/C. So where does this water go? Well there is a hose from the freezer to a pan underneath the fridge. There is a cooling fan for the condenser coils there which can dip into this pan. The idea is to use this water to help cool the condenser coils, making the fridge a little more efficient.

Anyway, so the failure has to do with the management of this condensation water. When it's not working, you get a puddle of water in the bottom of the fridge compartment which eventually leaks out to the floor. First thing to check- is the hose clogged? Yes it is, washed it out, but problem still happens. Next thing to check- behind the back wall of the freezer you find the evaporator coils. At the bottom is some cheap metal called the "drain trough". It is a funnel that leads the condensation into the hose. This is where the planned obsolescence comes into play. I'm convinced that the manufactures make this metal out of steal with just the tiniest amount of galvanization so that it will eventually rot out. I think even plastic would have been a better material.

It's theoretically possible to replace this metal, but consider the work involved: you need to empty the freezer, dry it out, remove the back of it, figure out how to move the evaporator coils out of the way without damaging them, unscrew the trough, and figure out how to wiggle it out. You need to do this at least twice (once to debug the issue in the first place, next to actually replace it). Finally good luck finding the replacement in stock (also add the time needed for this search). The fridge is maybe good for 12 years, but little chance of replacement parts stocked for that long. Certainly this is the case for my fridge, and I fabricated a temporary patch out of rubber.

Also, of course, there is absolutely no way for you to inspect this part before you buy a new fridge. Maybe it's even worse on new fridges, who knows?

Edit: check it out, someone else noticed this:

https://medium.com/@michael.grimshaw1/rusted-through-in-four...

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

#70
post #9

Related ... the last time I was in the market for a chest freezer (a "deep freeze") I wanted one that showed a log of temperature over time ... This, essentially, does not exist. It appears that there are laboratory freezers that support this (very simple) feature, but they are relatively small and very expensive . A better way to go is an electricity monitor on the plug, where you track electrical power over time an…

This is going to sound a little overkill, but I do have some experience in this area, and this is the right forum for it so...

Digital thermometers for freezers are relatively cheap (if you don't need them NIST traceable, anyway) and easy to get from any number of laboratory catalogues (See, for example, Thermo-Fisher or Cole-Parmer). You can even purchase a chart recorder that'll sit on top of your freezer if you want!

If you're just concerned about brown-outs and fluctuations, you can go with a cheap, magnetic max/min like the Cole-Parmer Jumbo (fine for consumer freezers) that sits on the front of the unit. You need to thread the wires through the freezer door, though, unless you're lucky enough to have a port on the side or back.

If you want a boatload of data you can go all out with a digital datalogger with a Type T thermocouple (Type T will even work reliably on -80C ULT freezers). I highly recommend Onset Hobos for reliability. There are also bluetooth and wifi models that allow you to get the data to your devices. As an aside, stay away from Oakton as a brand if you're doing anything mission critical.

If you don't want the wires sticking through the doors, I've had good success mapping temps with the Thermochron ibuttons - they are the size of a watch battery and some models work down to -40C. If you set the frequency low (e.g. every hour) they'll log data for months before you need to pull them. You can also get waterproof enclosures for them and throw them in the dishwasher for fun!

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