Inside a faulty Aldi dehumidifier.
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- Опубликовано: 27 сен 2024
- This unit is unusually large for a peltier based thermoelectric dehumidifier. But it's very typical of these units inside.
The mystery capacitor was just across the power rails. The pair of switches also had a small signal wire to light the "Tank full" LED.
The small dehumidifiers are only suited to very warm and humid environments. They require a significant temperature differential to extract moisture from the air. I ran this unit in my cold house for three hours and it formed frost on the condenser fins which only dripped off when the unit was turned off.
If you need a dehumidifier and have a warm house I recommend getting a traditional compressor type dehumidifier as they will pay their way quickly with very efficient and fast extraction of water from the air
If you need to use a dehumidifier in a cold location then the best type is a desiccant drum dehumidifier, which uses a rotating drum of desiccant material to absorb moisture and then extract it again with heat. They will pull out a lot of water in cold areas, and also put out a stream of dry warm air.
I use both types. Compressor in the summer and desiccant drum in the winter.
Another valid option for reducing humidity in cool areas is ventilation. Particularly if you use a humidity controlled fan. In remote locations you could use a filtered 12V equipment fan with small solar panel to draw air out and a plain filtered grill to allow fresh air to flow in.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.co...
This also keeps the channel independent of RUclips's advertising algorithms allowing it to be a bit more dangerous and naughty.
He should have sent a second package with a 5 gallon bucket of milk.
Poor Clive will get much bigger with all those feeders sending food :-)
Mmm 🤤
At moments of madness in the world your little corner of the internet is harmonious and peaceful Clive. Keep up the great work! 🙂
Dehumidifier so huge that he's got his own proper name, Christopher 😂
At least he has a full name unlike people named Topher like that kid from the 70s show. poor bastards with only half a name. 🤣
But does hit have its own ZIP code??
@S Hol then clean it so it can be called ex-smelly bastard.
Cleaning kits for cars Aircon systems work fine.
I’ve got exactly this. Except it’s white. And was bought from Maplins quite some time ago. Exactly the same melty behaviour occurred too. One day just before going to work and leaving it on all day as usual I, for some reason, just decided to reach down and feel the pluggery area, which felt alarmingly hot. I pulled the plug out, but what happened instead was molten plastic formed strands leaving one of the pin sockets still attached to the connector, the other came with the cable side!
Some time later after putting it aside, (and as Maplin had gone) I fitted a fairly hefty barrel jack arrangement drilled above the molten socket area. I took the molten socket out and left it vacant. It worked quite well for a long time like that, but we never (at my wife’s insistence) ran it unattended. I recommend nobody runs this model unattended, it’s clearly a fire risk. The thing no longer works for other reasons. It’s out in the shed, where I expect it will heal or see the error of its ways one day when I bring it in again.
the connector was obviously not suitable, 5amp or so is also a bit much for the common barrel type, as most only have tiny contact area on the outer surface,
Dude your voice is so relaxing. I just listened to this video in the background while doing something else, without even watching.
Clive, the Bob Ross of electronics!
@@theoldbigmoose I like that slogan! :D
He should sell T-shirts with that!
For those those playing at home, if you give a TEC electrical power to change temperature, it's the Peltier effect. If you use the opposite, it's the Seebeck effect.
I have a similar small unit, opened it up and replaced the fan with a noctua one. Went from being able to tell it was on in the next room to needing to check it visually every few days because even when I'm right next to it I don't know it's working. Great upgrade!
Congrats on 600k! Time to blow up something to celebrate.
I vote parliament..
Seconded
I was thinking along the lines of another chocolate rabbit.
Its not a dehumidifier its a magic water bottle filler
Well done Clive, you can read my native language quite well! Thumbs up! Greets from your Dutch fan!
You make the simple stuff fun and educational.
I did my first repair using your techniques, I knew watching your fabulous videos would pay off :D I bought a peltier de-humidifier off Amazon for my front room. The room has an exposed narrow vertical beam of stone in the middle of the window ( its a normal 2 bed terraced town house). The stone has been plastered over but in winter the cold penetrates the stone and draws condensation to the window and bottom of the double glazed units. I was sick to death of buying those granulated dehumidifiers, they filled up over a week. Long story short, the one from Amazon is of a good build quality but wouldn't do its job. I took it apart, nice 'full' switch, Led's work, button works, multimeter out, voltages on input 12V, 12V at stages on board, 5V at microprocessor, erratic voltages at transistor output to pelitier. Looked at it under a magnifier lens and solder looked bad. Re-flowed solder on tranny, it works! I put the unit about 4 inches from stonework and leave it on when I am at home. It collects enough water to get nearly to its tripping point (there is a float inside the collector) every 3 days or so, about 400ml (it has a 1 litre tank). It depends how cold outside and whether or not I put the heating on in that room. The rooms floor is boarded over a cavity. These houses are built on raw compressed sand and vented at floor level to the outside, under the floor. So I guess that room is always going to have musty damp air. However I must say this unit has eliminated almost completely the smell and no condensation has appeared on the windows, or more importantly the stone since using the unit. I was buying those granulated dehumidifiers at a rate of 1 to 2 a week at a cost of 69p each (pound shop). That unit will never cost that in electric per week and it runs from a wall wart, which gets quite warm but not worryingly hot. I guess for me, this electric unit is a cheaper option and there is nothing to throw into land fill every week. I wonder if anything can be done with the liquid from the granulated units as I imagine it would be very salty stuff, maybe use as a weed killer lol :) Sorry for such a long comment and, as ever, many thanks for your vids and much love, J x
Why not use a compressor one? It's way more efficient so way more cheaper to run.
I live in Australia I tryed a very similar device to try and remove some of the dampness in my poorly ventilated bathroom. I found that in a relative humid and warm environment it to be completely ineffective about 3ml collected per week and in consumed 25W. The solution was a box fan to blow into hallway after showers where it is better ventilated by open windows and air conditioning.
You're probably better off setting fire to your money rather than buying rubbish like this.
I live in Melbourne and my room has been around 25-30c recently with about 60%-70% relative humidity (if my sensors are correct), so near optimal operating parameters. This dehumidifier seems to collect about a full tank of water every 2 weeks approximately in my experience.
15:42 BC 2018 - not that old, only four thousand and thirty-six years! :-D
Before Clive?
4037. There is no year 0.
I had similar melting of a connector like that on a 12V fridge. I found an XT60 a much more suitable replacement as a connector.
You done hit 600k! Congrats clive!
So based on those specs this dehumidifier works best in the amazon rain forest...
There would definitely be plenty of humidity to pull out of the air. :)
30ºC with 80% humidity - as comparable to a car with a bloody pot full of hot water in it just making a big bloody mess
Big Clive says, no. A solar powered shed would be no good, too much tree cover.
I have found even when it is humid and warm that this type of device don't really work well. At around 30° and 80% humidity the most I was collecting was 15ml a week. Dosen't really have an effect in a room of any size. Maybe a cupboard would work but a jar of DampRid works better and doesn't consume 25W.
Or a bathroom after a long shower. That's what we use it for and it actually works: not even condensation on mirrors. Not very useful for rooms though.
The fan is not just to keep the hot side tool "to avoid damage". These TEC devices will achieve a given temp reduction (say 18degC) so if you want the cool side to be cold enough to condense water out of damp air passing over the fins, you have to keep the hot side cool too. I have a TEC-based 12v portable fridge and that works the same way - the inside can only ever get a fixed temp reduction on the air passing over the outside hot fins.
Right... These things can only produce so big of a temperature differential between the hot and cool sides. The cooler you keep the hot side, the cooler the cold side can get.
You say "from Lidl" but the title says "Aldi" ... .oO
Yeah. I often mix the two up because they are very similar shops.
@@bigclivedotcom Glad to see I'm not the only one.
Well LIDL was made after one of the founders of Aldi left
@@joshm264 There were and still are always two ALDIs - Aldi Süd (south) and ALDI Nord (north) in Germany founded by two brothers. LIDL was not founded by one of the ALDI brothers.
@@joshm264 I thought I heard they were brothers and then split up to compete against each other. I love my aldi's, in fact I was just eating corned beef I had bought there while I watched this video.
Peltiers have fascinated me for years. There's some fairly recent research into creating much more efficient TECs, which I hope become more mainstream.
Another cool patent I've seen recently is that AMD may be using ultra thin TECs between CPU and memory chips to help transfer heat better once they start 3D stacking their chips. Super neat!
Cool the CPU and warm the memory chips? That's interesting, never heard of it before...
Yeah I was wondering what they were going to do about heat with the 3D chip stacking.
Thermocouple technology is amazing. I'd like to see a more efficient one that converts heat to energy. Stanford Ovshinky, father of Nimh and much great tech, had hopes to make a cigarette sized box that could be dropped in to a camp fire and power a color TV. I've got some good ideas what one could do with such a device to revolutionize our society.
Probably the thin TEC's will be used to transfer heat to an intermediate thermal transport layer, so that the chips themselves are cooler, but the heat from the inner layers can be transferred by something with better thermal conductivity than silicon, though you are constrained, as it has to have a very similar thermal expansion as silicon to prevent you shearing the chip off of the attachment point, and most kovar alloys are pretty poor thermally compared to copper, but better than silicon. Or have one top and bottom to cool the chips actively to the heat spreader and the chip carrier, with a larger surface area. Probably hot processor on top, and memory underneath, with a lot of die space lost to the interconnections.
CaffeinatedTech forced chilled water through little channels was considered thirty years ago for such things...
Your method of explaining, and exploring new systems/designs are very similar to my own 😅
I had watched your video months ago for the white dehumidifier, and a friend sent this to me tonight because I was talking about TEC units.
Keep up the good work in educating and exploring!
It is nice to see that there are other fans from the Netherlands as well. So Clive, if you ever going to visit Holland, please let us know so we could bring you typical dutch stuff like drop, speculaas, pepernoten en stroopwafels.
It's just fun to say stroopwafels.
I had no idea Peltiers were based on thermocouple technology. I suppose I read "solid state" and my brain substituted "semiconductor". Thanks, Clive.
They might be inefficient, but (in generation mode) were allegedly used during WW2 to power spy radios. This mechanism powers many small space vehicles including Voyagers 1 and 2. They're also useful in the classic cooling mode for chilling sensitive front-end amplifiers well below ambient temperature, where all the K's matter.
I think they are silicon based. I may have mixed a couple of technologies up because I recall taking one apart and it had zig-zagging wire bonds.
They're based on P-N junctions, just like typical silicon components.
Your Dutch isn't bad at all Clive ;-)
Hi Clive, RUclips showed me a old vid of yours where you stripped a similar model on October 2014. Keep up the good work fella
Clive: based on an ambient temperature of 30°C, which is *absolutely* sweltering.
Australians without air conditioning: Uhh, I mean, you're not wrong, but also that's just the lower limit of what we'd consider "hot". It's when it hits 38°C that you really start suffering.
Clive, it's cute that you think that's a big dehumidifier. The ones sold in Canada hold at least 10 litres and have a compressor like an AC. :D
This is a placebo dehumidifier. I doubt it could lower the humidity of a closet by 1%.
@@misterhat5823 LOL! Maybe it is a dehumidifier for smurfs?
Doubt you could post it though, while this one will fit into a parcel dimensions and mass.
It's big for a peltier unit. My normal dehumidifiers take out litres of water and are plumbed in to drain it automatically.
@@bigclivedotcom I figured that's what you meant after I posted it, but decided just to leave it. lol Oh, speaking of peltiers, I came across a liquid cooling system for a CPU that uses two peltiers to cool the liquid. The were attached to a massive aluminium heat sink which attached to a rad, etc. It was very odd.
I have a very similar unit, and had to return the previous one as the plug (as you've shown) started to melt! I have to say it's a fairly effective, I leave it running next to my laundry airer and it'll fill its tank in about a week.
the connector they used was obviously not suitable for the current,, luckily its only low voltage,
30c sweltering hot lmao, here in Australia, 30c is our winters!
In Chicago, that's like a mild summer day where you don't bother turning on the air conditioning :P
I'd really like to see a new mre and a metal detector wand.....new series...dinner and a schematic
I believe that power supply is a number 4 on my toaster, lightly crispy and just a dash of black on there. Perfectly toasted!
Wow now I know how those electric coolers work!
The "reverse" effect of thermocouple junctions is employed by RTGs, Radioisotope Thermoelectric Generators. A mass of Plutonium 238 undergoes alpha decay, generating a significant amount of heat on one side. The other is heatsinked to radiate into space typically. Notable uses have been the Mars Curiosity Rover (MSL), the two Voyager probes, and the Apollo ALSEPs left on the Moon. There have been Soviet lighthouses using them as well!
Clive calls 30 degrees sweltering hot.
Meanwhile I Australia.... I was looking at my local weather forecast earlier, and thinking how good it is that we're cooling off with a maximum of just 32 in the next week. 😂
It's all about what you're used to. In the UK we consider 20 to be a good summer
I call 19 blazing... When it's not raining.... That always seems to be happening when I'm working outside 😂
@@DreStyle I need to get the garden sorted, been trying for 4 months now. It'd be easier just to have a pond.
I have one of these in a small room used as a wardrobe about 10x6. It's been going for many years and no mouldy cloths.
I love how you show us every function of a device that we are never going to buy simply because its broken and you tell us at the end of the video it's just a piece of junk lol. Classic
The translations are spot on! Cheers from Flanders!
I had one on my sailboat and it was great in a locker that got bad condensation, dried it right up. But they won't work on a very large space. I did run a full sized compressor one too during the New York winter, helped keep down condensation on the whole boat. Ah the fun days of shoveling three feet of snow off of your boat deck!
That reminds me of an old CPU heatsink in so many ways, even the dried out thermal paste.
I use a home brewed arduino controlled version to keep the condensation on my lathe under control but didn’t think of adding a thermal cutout on the hot side , i did fit one to the cold side to stop it freezing up so i may have to modify the unit and my sketch and fit a hot side cut out .
Thanks for the excellent video Clive !
plz share the idea syedshabirahmed2@gmail.com
In my humble opinion, companies add too much thermal compound to their heatsinks. The compound is there to smooth out any irregularities and tiny pits in the metal so increasing the surface area of the metal parts when pushed together. The conductivity of a good thermal paste is around 8.5 W/mK but it's 205 W/mK for aluminium so the compound actually acts as a thermal insulator when too much is used.
If the devices are mounted properly with enough pressure any excess paste would be squeezed out and not be an issue really.
Of course if the thermal paste is conductive one should pay attention to that.
The major issue is not that they put too much but that it's usually the cheapest compound they can get away with with predictable results
@@Yrouel86 As well surface finish, that ceramic is pretty much going to be nearly perfectly flat, but that fly cut plate is as rough and ready as if it was just extruded, just with less bowing. you would need to have a better finish, and lapping of the surfaces, to get decent heat transfer, which would only need a single match head of paste to cover the whole surface adequately. All the white on the aluminium is just showing all the hollows and poor finish.
Love the way he said cookie. Haha. The accent made it funny.
I think it's worth noting that if the net heat generated is useful (i.e. in addition too or instead of simple electric space heating) then all types of electric dehumidifiers are 100%+ efficient.
It still amazes me that an electric current can cause a cold side on just a connection to another conductor. I always believed it would cause heat due to resistance. I only learned of peltier cooling a few days ago.
30 degrees is a beautiful day where I live. That's only 86F!
2:30 - 30 degrees is definitely warm, but note that in some parts of the world, that might be a normal indoor temperature. Over here in Australia, that would still be on the warmer side, and we'd probably put on the air-conditioner by that point, but high 20s indoors are pretty normal temperatures during summer. However, point taken about the performance being based on "ideal" situations that are not going to be common in much of the world.
I'll definitely keep an eye out for dehumidifiers in the future! It's one of the few household electronics, so far, that I haven't ventured to tear down. Maybe the wife won't mind if I open up the one we have later...lol
Hello Clive. Those fans are more commonly used in computers; that one looks like a standard 120mm fan to me.
PC fans nearly always have symbols on their sides. There will be two arrows: one shows which way the blades go and the other shows which way the air goes.
In 1986, when domestic dehumidifiers were quite a new thing on the market, I bought a Toshiba DryMINI compressor dehumidifier. Quite heavy, and more foursquare in design than today's units, it has a mostly metal body (measuring 230mm by 340mm by 47mm high). It was expensive at the time, £200, as they were not in general distribution and I got it from a specialist heating/electrical place. It's rated at 199W, 1.5 Amps. I wanted it for my room at the time, which was on an exposed corner of the building, no cavity wall insulation, no central heating and single-glazed metal-frame windows. While there was no water ingress from outside, moisture-laden air from elsewhere in the house condensed in there, and things were getting mildewed. I installed the Toshiba DryMINI, and kept the draught-excluded door shut so that only the air in that room was processed. I decided to measure the water extracted. In the first 48 hours of operation (not running it at night, in case it sucked all the fluids out my body and I awoke in the morning a desiccated corpse), the DryMINI extracted TEN PINTS (5.68 litres) of water from the air in the room. I was impressed. And I am still impressed today because 34 years later it is still going strong! The fan has become ever so slightly rattle-y because the bearings must be a little worn (but the machine has always been incredibly quiet in operation). So, hats off to Toshiba for a durable product! I am a huge believer in dehumidifiers for here in the West of Scotland.
You may be able to get a new fan motor if it's an older product that used standard components. It may even just be a loose blade on its shaft adaptor.
@@bigclivedotcom Thank you for those suggestions! It's only the very slightest rattle. If and when it gets worse, I will investigate the options you suggest.
A new name for this contraption, the Horridifier
Nothing like a nice piece of Trim on a Sunday morning.
I had one exactly like that in white from Aldi, it worked excellently up until the point the plug melted and it didn't anymore.
bad design, the connector was obviously not suitable
If you've got one of these then save the condensate, it makes for a pretty clean distilled water substitute ideal for irons etc
Yep great for irons, just don't drink it!
Great, thanks for the tip. I have one of these exact same models several years old plus an iron hardly used (also from Aldi) so near perfect timing to make a small life change.
Yay Fontus! LOL
No, no, that was totally different, it didn't dehumidify air, it "pulled water out of thin air".
@@dingdingdingdiiiiing what a great idea! Maybe I should create a kickstarter?
Those Peltiers are bloody clever devices.
Clever, but terribly inefficient. I can't think of any use for these that a compressor couldn't do better.
I bought a box of raw Peltier plates. Why? For fun, of course! Running them with the cold side exposed and the hot side properly cooled will result in substantial ice very quickly.
One is a very large one that I haven't figured out an effective way to keep it cool when running at full power. It's a powerful one. IIRC it's like 200w. Even computer grade heat sinks allow it to get uncomfortably hot, and I don't want to blow it up.
I've also got a peltier mini-fridge and a peltier drink cup cooler. The latter can also build substantial ice on it if I don't have a drink sitting on it while set for full power.
These things are just so neat! :D Also, use computer-grade thermal compound to replace the goop they put in there. It's what I use, but I also work on computers a lot, so have a lot of it.
It'll improve transfer efficiency. You can also get compounds designed for low temperature operation, or for ultra long service life.
Being fair 30 degrees centigrade at 80% humidity sounds reasonablw for a clothes drying room/airing cupboard where you might put a dehumidifier to speed up the drying of clothes.
I have one of these models. Vaguely remember that the manual advises against doing this kind of thing.
This device can probably dry as many as 4 socks in a single day. That is two whole pair.
@Mason Bee it claims it can do 400 ml in a day, but reviews report less. Let's assume 200 ml/day, thus 50 ml per sock. My best, warmest socks for working outside in the winter almost certainly hold more than that after wringing them out by hand. I was thinking more of generic inexpensive adult sized tube socks.
Lekkere speculaas pop. The big cookie is called an speculaas doll. And it is very good.
Clive, you rock! You aught be a household name by now.
I have a cool box based on the same principle (but with a fan on the cool side too, as you were expecting) and it is really quite effective but probably not very efficient electrically. 240v or 12v, which is useful for pre-cooling before going away. Over 10 years old and still going strong.
15 % efficient at best.
The problem with the solar panel thing is, on sunny days, humidity is already going to be lower, unless it just rained. Humidity will be the highest on cloudy days.
The dryness of the thermal compound is not a problem. The grease that makes it 'wet' is not the effective heat transfer material, the white metal oxide is.
So long as the surfaces are tightly bound, do not move and do not have air pockets between them (all true with that screwed-together housing), then the compound works effectively.
Interestingly, there is an exhibit in the Toronto Science Museum that has interlaced metal prongs. You place your hand on them and press a button: one set of prongs goes ever so slightly warm. Press the button again and the other set of prongs goes slightly cold. Press it one last time and both prongs go to their slight temperature offset, but because skin senses temperature difference it produces quite a shocking but safe burning sensation.
I used Peltiers in a humidity control chamber, some years ago, to set the air temperature and that of a small container of water. Since %rh is a direct function of those two temperatures, we could create a consistent and fairly accurate %rh for checking calibration of sensors. The only trouble was the I²R losses in the Peltier limiting the lowest temperature of the water bath and that eventually the thermal cycling lead to a leak in a prototype that peed water all over the control board and corroded it in no time.
re-subscribed to your channel. Apparently your channel was one of the ones that youtube dropped my subscription for a while ago, and I have so many you got missed when I was putting them back. Anyway, I should be getting your channel updates again :D
Ah, the self-filling water bottle...
my favourite is the waterseer
I run one of these 24/7 in my workshop. The fans wear out eventually so I retro fit a ball bearing type fan and a another year or two out them.
I've had a few of this style of dehumidifiers and I've found that they always break down after a few months. I eventually got myself one of those desiccant dehumidifiers instead and it works so much better.
If you look how the inside of the water chiller looks after a year you would not drink that water. Sludge and white residue from the poor quality extrusion that is dissolving aluminium into the water, plus the lovely coat of bacterial slime covering all the inside of the tank. At least the refrigerant types are designed for the most part to be serviced, and also use a non corroding inside tank, with the hot water side being stainless steel, though also with an element that is not replaceable separate from the tank. Curse is that they use no copper pipe either, all steel brake lines, which rust from the outgassing from the foamed in place insulation, so it is not easy to repair once the pipes rot through. Lost a few fridges to that, you can only see the leak once you have removed the inner lining, and that is kind of destructive.
SeanBZA Did you reply to the wrong comment?
I've always wanted to know how it worked.
never heard of that little device, Thermal electric cooler very interesting.
We had a Land Rover 'fridge for our secret office milk stash. It was a super-insulated toploader armrest design.
It always had a beautiful white crystal of frozen dense ice covering the TEC.
Peltier cooling is always less than refrigeration/compressor/evaporator. BUT, Peltier effect is so much more economical to operate. If you have a lot of moisture to remove, Peltier is not for you. You will have to pay! Yeh, it’s a trade off!! 👍👍👍
600K! You need to do something special! :D
I was certain he was past 1M.
I have exactly the same one down in the cellar. I have to turn it off every so often because it actually freezes up into a big block of ice on the front
The thermal paste will often dry out, but it usually takes some time. So long as it's not disturbed, it's usually still relatively effective. Once you remove the heat sink though, you'd definitely want to clean it off and re-apply some thermal paste to the unit before re-assembling it.
Thanks - i have enjoyed your show
(Said in a Crocodile Dundee voice): That's not a dehumidifier. This is a dehumidifier. - Me as I show you the ginormous ones I have in the basement and the only slightly smaller one at the office.
the capacitor is likely just to dampen noise from the fan/s going back down the power supply cord.
Just being curious, would the noise make it past the power supply unit? I noticed the fan runs quite a bit after the switch has been released - maybe it's intentional to keep cooling the hot side for a few seconds after the peltier has been shut off.
That thermal paste looks very familiar
It's the same ceramic based thermal compound that caused the red ring of dead with the xbox 360 the blue light of death with the PlayStation3 and made 2000-2008 PC's very slow and noisy
makes sense
The paste was normal, it was the gpu being badly designed that bricked those consoles.
Also back in the day (pre ryzen) amd chips ran so fucking hot that even the expensive paste was dry in 1/2 year.
@@_DSch
The consoles were never really bricked, it was just a case of scraping off the hardened thermal paste and replacing it with a standard thermal paste and the problem was fixed.
@@MightyRude early consoles might have worked but still failed again later on.
You basically extended the timespan for the death a little bit.
Reballing or reflowing also never fixed the issue. On the PS3 Sony hacked the consoles in for repair so that the gpu from the slim is compatible to the fat. They would never do that if the chip design was not faulty.
"Bedrijfscontrolelampjee". Lol, so close! "Bedrijfscontrolelampje".
I've had a very similar dehumidifier with the same sort of plug exhibit the exact same problem. The connectors are crap, so I hard wired it.
tec's are nice to play with.
Clive, you make multiple references to TE coolers as not being efficient. Well, as with any other heat pump, efficiency is not fixed but has an inverse relationship with differential temperature across the TE cooler: low differential = high efficiency. Vapour cycle pumps can achieve higher efficiencies for the same differential temperature, but in terms of size, complexity and cost, we're not really comparing like with like.
It's critically important to maintain contact between the sinks and the alumina plates on the TE cooler, particularly on the hot side. Reason is that if Q is the heat pumped from cold side, the heat rejected from hot side is Q + VI. Accordingly, there can easily be twice as much heat passing through the hot side and, of course, in a hot ambient, you can reach the point where the TE cooler can maintain a differential but actually pump little or no heat: whatever cooling you get from cold to hot is offset by reverse conduction from hot to cold. By the way, the TE coolers contain alternate blocks of n and p type Bismuth Teluride electrically bridged with copper. Heat transfer goes in opposite directions for n and p so the current path alternates through the cooler so all the blocks pump thermally in parallel. Fascinating things: worked with them in aerospace industry decades back and have been intrigued to see them progress into the consumer market.
Yes and no. Yes, there are operating conditions that make them more efficient than other operating conditions. No, they are overall not efficient at all. "[…] thermoelectric junctions have about 1/4 the efficiency compared to conventional means (they offer around 10-15% efficiency of the ideal Carnot cycle refrigerator, compared with 40-60% achieved by conventional compression-cycle systems[11]" See WP for the source.
Nice Dutch Clive :).
You cant use standard PC paste, or a thermal pad because of how cold TEC's can get on the cold side.
The hotside, you could use something more efficient (AS5, Thermal Grizzly), but not the cold side.
The white stuff, is aluminum oxide paste (AS Ceramique type), which is better than the grey stuff for sub zero temps. This is why when you see people benching PC's with LN2, they use white paste and not grey. Unfortunately as you noted, the white stuff does dry out a lot faster then the grey stuff.
Also the wonderful thing about TEC's is you can run them on PWM, to make them somewhat efficient.
That is probably the best way to run a TEC and maintain a pretty competitive CoP against a phase compressor chiller.
Heatsink compound goes hard after a few years. It does it’s job still but not always as well. It’s goal is to fill the air gaps with a material that will conduct heat.
I have the maplin one. The fan needed changing. Otherwise we use it a lot.
Also yes, the psu broke.
The description translated from Dutch was pretty good, but here's a complete translation, with my comments in [brackets].
QUIGG
(NL) Compact air dehumidifier
- 65 watts
- Air dehumidification capacity: ca. 400ml/day at a room temperature of 30°C and 80% relative humidity [temperatures above 30 degrees used to occur about 0-7 days in an average year. In recent years this number has been higher, but not enough to make this statistic particularly useful]
- Removable water reservoir - capacity of water reservoir ca. 1.5 liter.
- Automatic shut off when the water reservoir is full - control lamp indicates full water reservoir
- ON/OFF switch [wow, such advanced features!]
- Operation control indicatorr [there's a typo in the original Dutch]
- Thermo-electric Peltier element [Clive's pronunciation was quite okay]
- Dimensions case ca. 20.5 x 12.5 x 35 cm [that's about 8 x 5 x 14 inches]
- Cable length ca. 3.2m [that's about 10 1/2 feet]
There's a typo in yours as well.
These mini peltier based dehumidifiers are a complete waste of time, money and electricity.
Buy yourself a proper compressor based unit and see the difference.
.........tell that to people like me who use a 200 watt atx power supply to powerr 1 to chill a single can!
Or better still a dessicant wheel one, because the compressor ones don't really work in room temps. below about 12 degs. C, whereas the dessicant ones do.
Yes, non repairable
Hell yea! Mine only uses like 160watts and it fills its tank in 24 hours, no mouldy weed for me! :)
phil955i yeah, I had to put a dessicant wheel dehumidifier in my attic to cut down the 80%(!!!) RH it gets up to during the winter otherwise. fun stuff happens when morons seal up an old house built with fireplace heating in mind...
How did you like that giant piece of "Speculaas"? It's very Dutch indeed.
I had to ration it out over a week.
In Canada, plugs like that tend to max out at 120v 7A. If that one was running twice the voltage at 5A, I can see why that might be an issue ...
i bought 1 of these exact dehumidifers for $5 at a goodwill(resale shop) and converted it into a can chiller
also, the fan doesnt cool the air and then heat it back up like a traditional dehumifier, the plastic is designed in such a way that the airflow is more or less sealed from the hot side to the cold, there is a gap where the water chamber seats on it but not enough to be intentionally designed for the purpose, the hot gets sucked in the back and out the top, also my version the heatsink was different, it was a normal square heatsink but the bottom edge had a leading angular bit to direct water droplets into a smaller area and encorrage them to fall ||||||||||/
hey @bigclive sorry about 3 replies in 1 thread of comments but have you considered getting 1 of those lamp/arm/universal positioner things that works on springs, counterweights and friction to keep an object(ie your current recording phone) at a set position so you can keep to your recording format but have much greater range of zoom and for larger objects like this, if you really want to gild the lily as dave jones would say, add a ring light with spring loaded clamps to grip the phone from the sides and leave back/front fully accessible here is a crude ass-cii |/\/\/\/\-(( || )) representation of it kinda like a lab stand or helping hand with a lighted phone mount on the end instead of alligator clips
15mm 01 : yes there is a thermal cutout in case the fan shot down and the peletier overheat ..
Does Christopher not know, Lidl give a 3 year money back guarantee
Between the 2 ceramic plates are Peltier diodes :) They transfer heat from one side to another when electricity is passed through these diodes, the so called Peltier effect.
Actually the compressor based units do put out a bit of heat. When mine's off it emits 32c air, when it's off but the fan is still running it emits around 18c. This is with ambient temp of 23.
When the water is condensed out of the air it actually gives off heat during the transition.
As someone who lives in the desert I can't help but go "DE-humidifyier?".
The thermoelectric thingies use semiconductors rather than metals- you can make semiconductors very electrically dissimilar to each other (p Vs n type) so you get a bigger effect+ metals are a bit too thermally conductive to perform well (the heat flows backwards)
And I thought, Aldi is a german super market chain - two german brothers with the same idea. But they have parted, one took south germany and the other one took north germany. At this time, when both brothers where alive (one died), these where chains on their own, but now its one big chain.
30C definitely not the upper limit in our office.
30 degrees very hot?!....... Laughter from a country that reaches 45 deg.C in summer !
Looks to basically be the insides of a mini-fridge, but nowhere to store the beverages, but that said I ditched my mini-fridge in favour of a proper one, because it was too noisy and barely cooled... :P
30°C is upper limits for u , that's a normal day here in South Africa :P
Hope u have an amazing day :)