[Request] How long will it take my mini fridge to cool 130 12oz soda cans? theydidthemath

http://ift.tt/2wNOhZP

I just purchased this mini fridge http://ift.tt/2xvf0Oi to keep my insulin cool in. I also like diet soda, so I put 130 12oz cans inside of it.

I have wireless temperature probes in both of my basement mini fridges and it's been interesting to watch thermodynamics in action.

The internal temperature was 35F before loading up the fridge. When I was done loading the unit, it was at 41F. The temperature has been climbing and seems to be hanging at 65F right now. The soda was at room temperature (72F) before they went into the fridge.

How long will it take for the internal temperature of the refrigerator to stabilize at 35F?

I have the following performance data on the fridge:

• Capacitor Run or Induction Run: 90F
• Refrigerator Temperature: 33F to 50F
• Low Side Pressure: 60psig
• Refrigerant: R600a
• High Side Pressure: 150psig
• Wattage: 70.5W
• Amps (Running): 1.0A
• Base Voltage: 115V (127V max)

Submitted September 23, 2017 at 03:45PM by Carmen_Electra http://ift.tt/2wNGk75 theydidthemath

[Request] When I open my refrigerator or freezer doors how many calories worth of food do I have to take out to balance the energy lost in cold air escaping? theydidthemath

Was just thinking this morning as I opened the refrigerator to get a leftover piece of bacon if what I get in calories from that one piece is enough to justify the cost of energy in making all the warm air that gets in cold again.

Submitted September 12, 2017 at 10:15PM by Presidentofsleep http://ift.tt/2wVseVg theydidthemath

[Request] How much electricity would an average refrigerator use if left open for 11 hours? theydidthemath

In kWh please. Other factors that may play into this:

• Figure it's around 88°F outside. Could be anywhere from 75-85°F inside.
  
• Normal freezer/fridge combo, with the freezer on top. Freezer is shut, only the fridge portion is open.
• There are two light bulbs inside the fridge.
• The fridge is not brand new, nor is it very old. Probably around 5-10 years old, and not a fancy/high-end model.

Let me know if there any other factors here I'm missing.

Submitted September 06, 2017 at 01:22AM by AmbrosiusAurelianus http://ift.tt/2j0iRxz theydidthemath

[Request] How much electricity would an average refrigerator use if left open for 11 hours? theydidthemath

In kWh please. Other factors that may play into this:

• Figure it's around 88°F outside. Could be anywhere from 75-85°F inside.
  
• Normal freezer/fridge combo, with the freezer on top. Freezer is shut, only the fridge portion is open.
• There are two light bulbs inside the fridge.
• The fridge is not brand new, nor is it very old. Probably around 5-10 years old, and not a fancy/high-end model.

Let me know if there any other factors here I'm missing.

Submitted September 06, 2017 at 01:22AM by AmbrosiusAurelianus http://ift.tt/2j0iRxz theydidthemath

[Request] If I put a hot leg of pork straight into the refrigerator, by how many degrees will it raise the ambient temperature? theydidthemath

I keep reading that meat - especially pork - should be left to cool before being refrigerated. The reasoning is that it raises the ambient temperature inside to above 40F, which is considered unsafe. I'm a little sceptical of this: is it possible to calculate whether this is likely to happen, given certain assumptions about the size of the joint etc?

Submitted July 26, 2017 at 04:17PM by HaplessBates http://ift.tt/2uwH2Yv theydidthemath

[Request] How much does it cost to open the fridge for ten seconds? theydidthemath

My grandparents are extremely frugal. For a lot of things this makes sense, but one rule seems pretty ridiculous to me. They want me to make sure that if I put several things in the fridge, I put them in at the same time, even if it means leaving the jelly out for a few minutes.

I'm curious to see if this makes enough sense to follow. If I open the fridge for ten seconds, how much does it cost?

Assume average cost per kilowatt hour, and an average sized refrigerator.

Submitted July 24, 2017 at 04:35AM by Ajreil http://ift.tt/2vzv12O theydidthemath

[Request] Cost of Refrigeration of Foodstuffs theydidthemath

Question

Assuming a modern household refrigerator of average cost and electrical efficiency, how long can you store an item of food inside the freezer before the cost of the energy consumed keeping it at -4°C exceeds the cost of the item itself?

(x-post from /r/askscience)

Unimportant Unscientific Backstory

So. My family has a pretty lax approach to food safety, and we're generally okay with consuming things past the listed expiry date on the package, within reasonable means.

What I found not reasonable, though, is a half-eaten 400g packet of seaweed which has been sitting in the freezer for a decade that the parents refuse to let me toss out, having expired in 2008 (oh, they'll eat it, they claim. Eventually. 🙄)

Apart from bringing it out annually to celebrate its birthday, I also regularly mention that the cost of refrigeration might very well have exceeded how much the item is worth in the first place.

I tried doing some research, but my Google-fu was way too weak, so appreciate the subreddit's help in ballparking this figure. 🔬 Physicists, Electrical Engineers, Food Scientists - anyone with an expert opinion on this; over to you, please.

Variables

I would immediately assume the answer to this question might depend on many factors like those listed below, so I've attempted to put in brackets what I think would be sufficiently generic options for calculation, but feel free to substitute your local equivalents if it helps

• heat capacity of food (1kg deboned chicken breast)
• price of food item (New York grocery store)
• storage temperature (-4°C)
• room temperature (25°C, 1atm)
• unit cost of electricity (New York 2007-17 utility rates)
• efficiency of freezer (EPA Energy Star, 2007 models)

Very importantly, would the cost of freezing that quantity of chicken breast be significantly greater than freezing the same volume of air?

Thanks in advance to anyone who can solve this long-ongoing bugbear of mine!

Submitted June 09, 2017 at 11:26PM by Cymcune http://ift.tt/2s5zKtD theydidthemath

[REQUEST] What is he power output of a hamster running in a hamster wheel, and could how many would it take to power my television, refrigerator, and microwave assuming I use them at normal rates? theydidthemath

No text found

Submitted April 26, 2017 at 08:56PM by lordg52 http://ift.tt/2pzJnk4 theydidthemath

[REQUEST] What is he power output of a hamster running in a hamster wheel, and could how many would it take to power my television, refrigerator, and microwave assuming I use them at normal rates? theydidthemath

No text found

Submitted April 26, 2017 at 08:56PM by lordg52 http://ift.tt/2pzJnk4 theydidthemath

[Request] How much CF4 would one need to raise the average temperature of Mars to 32 degrees Fahrenheit/0 degrees Celsius theydidthemath

Look, rocketry is becoming cheaper and cheaper by the month now and everyone has been thinking it. How much refrigerator coolant would be needed to create a more temperate atmosphere on Mars?

Submitted December 16, 2016 at 05:19AM by theguywithacomputer http://ift.tt/2gQF3HH theydidthemath

[request] How much time would I have to leave an average refrigerator open for it to actually cost significantly more money? theydidthemath

No text found

Submitted December 03, 2016 at 07:21PM by Quartent http://ift.tt/2gMifqn theydidthemath

[request] How much time would I have to leave an average refrigerator open for it to actually cost significantly more money? theydidthemath

No text found

Submitted December 03, 2016 at 07:21PM by Quartent http://ift.tt/2gMifqn theydidthemath

[Request] If you switched to driving an SUV from a car for a year, would the extra co2 released be equivalent to the co2 from powering an open fridge for 6 years? theydidthemath

Sorry about the title, in College Writing we read an essay from These Times in 2001, by Bill McKibben, about climate change. He says "If you switched today from the average American car to a big SUV, and drove it for just one year, the difference in carbon dioxide that you produced would be the equivalent of opening your refrigerator door and then forgetting to close it for six years." My class got in a minor discussion about the accuracy of this claim. I tried finding it for myself but to little avail. Keep in mind this was written in 2001. It would be awesome if someone could get answers for both 2001 and more recent years, but either one would work too.

Submitted September 16, 2016 at 07:15PM by jokester109 http://ift.tt/2ccGudQ theydidthemath

[Request] how many panels would it take to run this refrigerator in a field? theydidthemath

Taken from here

Submitted July 11, 2016 at 11:07PM by tinyOnion http://ift.tt/29K2gau theydidthemath

[Request] How much hot soup would it take to negate a refrigerator's cooling effect? theydidthemath

No text found

Submitted May 30, 2016 at 04:17PM by LevynX http://ift.tt/1TQTOGg theydidthemath

[RDTM] /u/just_some_tall_bloke calculates how many AA batteries it would take to run a refrigerator theydidthemath

http://ift.tt/1ONi1u6

Submitted December 06, 2015 at 07:32AM by trogan77 http://ift.tt/1HNTPIx theydidthemath

[Request] Which is going to win 5000 billion refrigerators or the sun in our solar system theydidthemath

Lets assume that all the fridges are 18°C and sending them to the sun isn't a problem

Submitted March 21, 2015 at 11:13PM by Randomsaucer http://ift.tt/1OiQfWN theydidthemath

[Request] What would be the total impact if Americans maintained the optimal temperature in their refrigerators? theydidthemath

As Adam Carolla recently pointed out on his podcast, no one knows what the temp in their fridge should be. If it's too warm, the food spoils faster. If it's too cold, the energy is wasted. For an appliance that it so taken for granted and runs literally all the time without exception, it's weird we don't know more about it. Fridges frequently have features that adjust the temperature via buttons/dials, but they rarely show the actual temperature (C/F).

Is there a way to ballpark at what temp people's fridges are and whether it would make a material impact to raise/lower it a few degrees?

Submitted February 06, 2015 at 03:58AM by mogifax http://ift.tt/16lR0w4 theydidthemath

[Request] If it was legal for the government to pay cash to adults who volunteer to get free sterilization, how much could the government pay and still come out ahead in the long term? theydidthemath

For an article about how not having kids is green:

Take, for example, a hypothetical American woman who switches to a more fuel-efficient car, drives less, recycles, installs more efficient light bulbs, and replaces her refrigerator and windows with energy-saving models. If she had two children, the researchers found, her carbon legacy would eventually rise to nearly 40 times what she had saved by those actions.

It's a fair guess that people who are lower income, and more at risk of an unwanted pregnancy would be more willing to accept such an offer. One of the best indicators of success is parental involvement, and wealthier parents usually have more free time and resources. Of course this isn't a flat rule, but I'd imagine anyone willing to take cash for self-sterilization wouldn't be the best parent.

Aside from environmental impact, what other aspects are significant costs of a new citizen? Education? Employment resources? Is there a case where no amount offered would help offset future costs?

Submitted October 22, 2014 at 09:11PM by KevlarGorilla http://ift.tt/1w9Vocx theydidthemath

[Request] If it was legal for the government to pay cash to adults who volunteer to get free sterilization, how much could the government pay and still come out ahead in the long term? theydidthemath

For an article about how not having kids is green:

Take, for example, a hypothetical American woman who switches to a more fuel-efficient car, drives less, recycles, installs more efficient light bulbs, and replaces her refrigerator and windows with energy-saving models. If she had two children, the researchers found, her carbon legacy would eventually rise to nearly 40 times what she had saved by those actions.

It's a fair guess that people who are lower income, and more at risk of an unwanted pregnancy would be more willing to accept such an offer. One of the best indicators of success is parental involvement, and wealthier parents usually have more free time and resources. Of course this isn't a flat rule, but I'd imagine anyone willing to take cash for self-sterilization wouldn't be the best parent.

Aside from environmental impact, what other aspects are significant costs of a new citizen? Education? Employment resources? Is there a case where no amount offered would help offset future costs?

Submitted October 22, 2014 at 09:11PM by KevlarGorilla http://ift.tt/1w9Vocx theydidthemath