A deleted scene! Cube fridge pull-down
Added 2024-09-23 16:38:05 +0000 UTCOne of the reasons the Peltier fridge video took so long was that the script was not gelling for me. I had initially thought a head-to-head test between the cube fridge and the Peltier "fridge" would be compelling, so I set about that testing. Ultimately, since even the giant American fridge needs less power, I realized I was putting way too much focus on that specific angle so I cut it.
But here's the data! (sorry it's a little blurry, I just grabbed it out of PDF report)
And here's what I wrote about it:
I wanted a head-to-head comparison, though. I mean, the blue fridge uses 55 watts no matter what so it doesn’t really matter but I initially tested it completely filled, so I loaded this up to the brim with 33 warm cans of sparkle water, threw in a data logger to track its temperature progress, and measured its energy use as it worked to cool it all down. Being completely loaded up it struggled quite hard. Still, after about 19 hours and 20 minutes, it got back down to food safe temperatures - so cooler than the blue fridge could manage, and more quickly. And for the icing on the cake, it only needed 576 watt-hours of energy to do it, meaning it used 29.79 watts on average. To cool down all of this. As a reminder, that’s compared to 55 watts of constant draw to only kind of cool 6 cans.
In addition to this being somewhat redundant, I also decided to cut it since I stopped the data logger before 24 hours. I checked the logger and saw "oh, it's back below 41" and ended it which in hindsight was silly, and it made the inclusion of this test feel pretty arbitrary. But anyway, that's it!
Comments
I fully understand the principles of how to convert properly. I just don't do it often enough* to remember the numbers involved, so it's easier to ask Google. I was well aware that Google was going to give me the wrong answer on this occasion if I simply asked it to convert 30. My method was to ask for 0C in F, add 30 to that value then ask it to convert back. * Only when I see something on North American Youtube channel without Celcius conversions added in which is pretty rare these days. Distances, weights, volumes etc are all done frequently enough that I can do them mentally without specifically calculating it. anything.
DrumBrakes
2024-09-25 07:16:13 +0000 UTCAnd then there are the weirdos who use small caps instead of lowercase letters
Scoott
2024-09-25 02:06:42 +0000 UTCKenneth Morenz is correct, but did not provide the reasoning. If you are converting between F and C actual values, the trick is to align both by exploiting -40F = -40C; So, you add 40 to whatever value you have, multiply the ratios, and then subtract the 40 again. However, when it comes to temperature _differences,_ as "below ambient" implies, you do not need to do the shifting again, because that part has cancelled out for the two temperatures needed to do the differences. So, just multiply the ratio and be done with that.
KJ Xiao
2024-09-25 01:21:36 +0000 UTC...I'm not sure why anyone would want their scripts shouting at them.
Egor A. Palchyk
2024-09-25 01:05:31 +0000 UTCThis topic got me reminiscing about my similar journey into thermoelectric cooling. Back around 1985 I was involved in the electrical engineering for Aquarius, a subsea habitat for NOAA. (https://en.wikipedia.org/wiki/Aquarius_Reef_Base) and one of the items included was a thermoelectric refrigerator. I couldn't believe the amount of power it was claimed to require! That set me off researching the technology and its limitations! Thanks for the memories!
HarveyB
2024-09-24 07:00:45 +0000 UTCI actually came here to comment the same suggestion. Since the limiting factor of the Peltier is how well and how quickly it can shed the heat on the hot side, I'm also curious about how it would behave inside of a refrigerator.
David K
2024-09-23 20:19:51 +0000 UTCI have a stupid idea for an experiment that might yield interesting results: Put the Peltier fridge INSIDE one of the other fridges. I'd be interested to see what happens, though you'll probably need to fill it with ice packs instead of soda cans. Depending on positioning, you could maybe remove the fan from the Peltier fridge. I'd also be curious to see the results if you insulate the front door / add another Peltier element thing / add a thermostat.
A Very Throwable Brick
2024-09-23 19:59:49 +0000 UTC70 currency units is more than I can afford. I spent all my CUs on power converters at Toshi Station.
Em Wintle
2024-09-23 19:47:29 +0000 UTCI’d been trying to find a way to cool the tank bag on my motorcycle as I cross the Texas desert. My first thought was peltier, but after making some sketches, I realized there was no realistic way to remove the heat from the back of the device without resorting to liquid-filled tubes, or some ridiculous heat pipe. I ended up using ice packs that I put in the motel or campsite (if lucky) fridge every night. Keeps the tankbag cool enough for about two hours. Using the chemical ampoule kind would be better, but too expensive. And really bad from a landfill perspective.
Em Wintle
2024-09-23 19:44:49 +0000 UTCI'm only now learning that you write your scripts with grammatically proper capitalization, instead of using CAPS LOCK, as professional scriptwriters and passionate Internet postulators tend to do. Seeing as how you're both, this comes as quite the surprise to me! :)
C.J. Malm
2024-09-23 19:07:47 +0000 UTCNo, you would just use the ratio of 9/5. You wouldn't subtract the 32. So, a 30F drop would be 16.67C.
Kenneth Morenz
2024-09-23 18:42:44 +0000 UTCConsidering the industry standard for that sort of thing is an ice pack that you have to swap out manually, might still be an improvement. If my kitty actually cared for wet food, I’d give it a try, but nope.
Scoott
2024-09-23 17:48:44 +0000 UTCAlmost certainly, yes
Technology Connections
2024-09-23 17:40:10 +0000 UTCGot pushed an ad for an automated wet food cat feeder with “semiconductor cooling technology” — wonder if that’s a Peltier thing
Scoott
2024-09-23 17:38:44 +0000 UTCYeah, one of the reasons I hunted down a portable compressor fridge. Got lucky, found one for 70 currency units as the fancy electronics were fried. Hooked up a cheap therrmostat, works. *bam* The power consumption as an office fridge is ridiculously low compared to the peltier ones.
Thomas Ruecker
2024-09-23 17:17:22 +0000 UTCWithout a doubt the hardest thing about converting temperatures between F & C is that 0 is different. Neither system is better than the other in that respect. So when you tell us the Peltier fridge can cool to 30 degrees below ambient, and I try to convert 30F into C it's clearly wrong if the answer is -1.111* (I always appreciate the effort involved when you do give us C values, and I absolutely do not hold it against you if you don't) *A great example of this was Robert (Aging Wheels or Under Dunn?) insulating his garage roof.
DrumBrakes
2024-09-23 16:57:39 +0000 UTC
