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French startup unveils new residential thermo-acoustic heat pump
- alexose 4y agoSuper cool to see someone trying to commercialize this technology. Fun fact is that the JWST cryocooler operates on a similar principle (although the implementation is quite different). Relatedly, I found this fantastic video on to how to use the thermoacoustic effect for heating and cooling a few months back: https://www.youtube.com/watch?v=kkBBkQ8jFRY https://www.youtube.com/watch?v=kkBBkQ8jFRY
- doctor_eval 4y agoI expect to lose karma for saying this, but it’s not just super cool but also super hot.
- __alexs 4y agoHyperspace Pirate on YouTube is working a DIY Pulse Tube Cooler that also uses thermoacoustic principals. His videos go into quite a lot of detail about the various parts and how they need tuning for everything to work. https://www.youtube.com/watch?v=WOmjJFk8rl0 https://www.youtube.com/watch?v=WOmjJFk8rl0
- kragen 4y agoprobably if you are trying to understand how this works it would be useful to read https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine https://en.wikipedia.org/wiki/Thermoacoustic_heat_engine
- fragmede 4y agoThanks. I was trying to square the very first sentence of the article "Equium has developed a new thermo-acoustic heat pump core that reportedly produces 3 kW to 4 kW of heat for every kilowatt of power it consumes." for not violating the first rule of thermodynamics.
- goodcanadian 4y agoYes, this regularly comes up with any heat pump discussion. Strictly speaking, it is not producing heat, it is moving heat from outside to inside (or vice versa for an air conditioner, or for that matter, a refrigerator).
- kragen 4y ago⅔ to ¾ of it anyway
- a9h74j 4y agoThis and the posted article mention a speaker or driver. No mention of how they deal with aging or fatique effects in e.g. a flexible ring connecting to the frame and holding the cone. Have done applications where a special "high cycles" acoustic driver had to be sourced.
- kragen 4y agoi hadn't thought about that; it seems especially important given that they're talking about kilowatt power levels and macroscopic wavelengths, so a nice piezo probably won't cut it how did you source the high cycles driver, what was it made of, and how much did it cost
- MayeulC 4y agoWhat's the efficiency compared to traditional compressors? I imagine there are a lot of opportunity for thermal energy to leak on the sides... Edit: 20-30%, up to 40%, according to wikipedia.
- idiotsecant 4y agoI am building right now and my state (washington) recently decided no more natural gas heat, heat pumps only. That's great for the warmer side of the state but most heat pumps don't work great when it's 10 below - they approach zero efficiency the colder it gets. Blueheart seems to claim they can output 60C on the hot end when the cold end is -20C. In addition, EQUIUM seems to claim a 30 year lifetime on their acoustic chamber because it has essentially no moving parts, it's just a pressure vessel. If both of these things are true it could eventually be an advantage over heat pumps for people in cold conditions or people who are sensitive to maintenance costs once the technology is mature. Or all the (very vague) specs could be marketing junk and it's vaporware. Neat either way.
- moloch-hai 4y agoModern heat pumps work down to pretty low temperature, but the amount of heat you can get out at a low temperature may not be enough to stay warm with. As outside temperature goes down, you need an increasing amount of heat input. At a particular point (which depends on temperature and wind speed) capacity is exceeded, and inside temperature falls. Then you need an alternative source of heat. Typically this is a propane furnace, but may be a resistive heater. The heat pump saves on your bill except during cold snaps, and then cost spikes.
- thehappypm 4y agoTypically the backup is resistive, in a ducted system, it’s basically a big heater coil in the heat exchanger area. One of my two properties has one. It has never been used though, AFAIK, because it hasn’t gotten cold enough yet (and frankly, in Eastern Massachusetts, it is not very common anyway).
- aaron695 4y ago[flagged]
- honkler 4y agopeople crave hype. Investors love it.
- a_mechanic 4y agoit does not use refrigerant which is unique
- RandomWorker 4y agoCritical issue with this technology it only really works well with helium.
- kragen 4y agono, though helium does have real advantages hydrogen is actually even better iirc but air works too
- andrewflnr 4y agoDifferent issues with that, but maybe no worse than a bottle of kerosene.
- kragen 4y agoa bottle of kerosene might be 500 g, or 21 megajoules according to https://en.wikipedia.org/wiki/Energy_density#In_chemical_reactions_(oxidation) https://en.wikipedia.org/wiki/Energy_density#In_chemical_rea... but 2 ℓ of hydrogen (i don't know how much you'd use in a residential thermoacoustic cooler so that is a guess but probably the right order of magnitude) is only 0.02 megajoules, a thousand times smaller otoh the kerosene doesn't form an easily detonated high explosive if it mixes with air, and the hydrogen does, and 20 kilojoules can still be plenty fatal in an explosion
- moloch-hai 4y agoSeems like N2 would be a better choice unless absolute molecular weight is important. Helium is hard to keep confined. Reading up a bit, it seems like this has to be a traveling-wave device to get the efficiency advertised: standing wave devices seem limited to a Carnot cycle, where a traveling wave device can operate a Stirling cycle.
- makomk 4y agoAbsolute molecular weight is important. Can't remember why off-hand but if I recall correctly there's a pretty substantial efficiency hit from using heavier gas molecules and conventional Stirling engines have a similar issue.
- fnordpiglet 4y ago[flagged]
- deleted 4y ago[deleted]
- QIYGT 4y agoReally hoping this kind of tech to ends up in window AC+heat units soon for those of us in apartments.
- guywhocodes 4y agoThe stated numbers seem comparable to a compressor based system so seems promising.
- anotherevan 4y agoDoes this mean I now have a good excuse to buy noisy toys for my grandchildren?
- c_o_n_v_e_x 4y ago>in a closed-pressure vessel filled with helium at a pressure of 30 bars... >It has a 30-year lifetime, with an easy installation process Normally, any kind of pressure vessel (steam, compressed gas cylinders, etc.) is subject to routine inspection and hydro-testing for re-certification. What happens if/when it needs to be serviced? Do I need to draw down a crazy level of vacuum before charging it helium (or whatever working fluid)? >Traditional fixed-output units cycle between on and off multiple times a day, switching between zero and maximum capacity to achieve the right temperature balance. But the new heat pump modulates its output to continuously provide the desired temperature. New heat pumps / air conditioners already do this with variable speed compressors and fans.
- TylerE 4y agoThere really isn’t such a thing as a “crazy amount of vacuum”. The most vacuum you can have is 1 bar. From a structural standpoint there’s no difference between a very bog standard vacuum, like say the 2psia or so a vacuum cleaner produces and a 10^-10 physics lab vacuum that takes hours of pumping.
- MobiusHorizons 4y agoFrom the stress on the system perspective you are right, hard vacuum is not significantly more stressful on the container than low vacuum. But I think the parent was talking about the cost of maintenance. If the pressure vessel needs recertification over it’s lifetime that will be expensive. If refilling the container requires high purity (and therefore more work removing the air and other contaminants before filling) the process will be even more expensive.
- guywhocodes 4y agoThis has been a pet peeve of mine for a long time, am I correct to assume that deep vacuum is only hard to maintain because very very small impurities in seals etc will cause a relatively large amount of off-gassing?
- TylerE 4y ago
- doctor_eval 4y agoCan anyone tell me why they use Helium rather than say Nitrogen? I thought I read somewhere that we are running out of He.
- xeromal 4y agoWe're running out of cheap helium. For applications like this, I'm sure it'll be fine.
- mechhacker 4y agoHelium is a more effective heat transfer medium with lower molecular weight. Hydrogen would be more efficient but it tends to cause issues with the containing material and leaks.
- jnsaff2 4y agoFrom this [0] NPR piece: Helium is the only element on the planet that is a completely nonrenewable resource. On Earth, helium is generated deep underground through the natural radioactive decay of elements such as uranium and thorium. "It takes many, many millennia to make the helium that's here on the Earth," says Sophia Hayes, a chemist at Washington University in St. Louis. The helium seeps up through the Earth's crust and gets trapped in pockets of natural gas, where it can be extracted. Like hydrogen, its immediate predecessor on the periodic table, helium is lightweight. But unlike hydrogen, it doesn't readily combine with other elements. So, once helium reaches the surface, it can easily escape the Earth's gravitational pull. Other resources, such as oil and gas, may turn into pollution or be difficult to recycle. But only helium physically disappears from the planet. "It's the one element out of the entire periodic table that escapes the Earth and goes out into outer space," Hayes says. [0] - https://www.npr.org/2019/11/01/775554343/the-world-is-constantly-running-out-of-helium-heres-why-it-matters https://www.npr.org/2019/11/01/775554343/the-world-is-consta...
- Someone 4y agoFTA: Because helium remains a gas until -200 C, we can achieve higher temperatures inside our heat pump core N₂ boils at −195.8 °C, but that will be higher at 30 bar. Next question: why do they need gas at lower temperatures to achieve higher temperatures? Do temperatures inside that acoustic wave vary that much?
- owenfi 4y agoCan this run in both directions? I’m eager to explore radiant heating and cooling (in like a 5-15 year time frame) and wondering if it might be good for that.
- nraynaud 4y agoyes, one reductive way to see it is that they physically move the cold molecules on one side and the hot ones on the other side. So now wether you want to steal the hot or cold side to bring in the house is "your choice" (quotes, because the temperatures involved have to be useful for you to want to bring them in). The side you don't want to bring in the house will soak in the outdoors.
- fransje26 4y agoOne part to the heaters, the other to the fridge or freezer. Win-win in winter.
- jacknews 4y agoI wonder what the efficiency is at higher temperature differences. For example, I would like a water-sourced aircon which cooled a radiant or chiller circulating system on the cold side, while heating incoming water for hot water on the hot side (plus an 'overflow' cooling ground loop if necessary). Maybe this isn't beyond the ability of current systems, but I think having a fairly large gap of 60C hot/5-15C cold is inefficient currently, and maybe a reason you don't see this obvious setup too often.
- micro_cam 4y agoA standard heat pump water heater does that but will only provide a couple degrees of cooling to meet standard domestic hot water needs. You can also get pool heater heads for heat pumps/ac units though last time I looked not all were available in the us.
- jacknews 4y agoYes that's a great idea. When I said 'overflow ground loop', I obviously I meant 'dump any excess heat into your swimming pool'. In fact this surely makes sense for existing aircon, just for better efficiency.
- mattmaroon 4y agoI’m wondering how or if helium supply issues might make impact scalability of this. Yet another in a long list of reasons we should ban selling the stuff to the public.
- bilsbie 4y agoAFAIK Natural gas extraction produces a whole lot of helium. We just have to bother to capture it. (Please correct me if I’m wrong. I read it on slashdot decades ago)
- Accujack 4y agoYou're correct. There's no shortage of helium, at least for several hundred years. There just aren't many gas wells capturing it because it didn't make any economic sense to do that until recently.
- jabl 4y agoThat is true, but OTOH if we're going to address climate change we can't keep on extracting natural gas like there's no tomorrow. So helium could become a pretty expensive thing.
- nraynaud 4y agoIt's right, and it's not expensive enough to have large scale recycling and conservation measures (some scientific labs have recycing systems already, but they are not the ones wasting the most). It's one of those cases where there is a shortage "at that price".
- SamPatt 4y agoWhat exactly would you prefer helium to be used for other than quiet, efficient heat pumps? Banning the sale of helium is foolish. The market is already responding to less supply, as it always does. We don't need people running around stopping innovation because they don't understand how price signals work.
- deleted 4y ago[deleted]
- dilippkumar 4y ago> The heat pump has a coefficient of performance (COP) of three to four, which means that it produces 3 kW to 4 kW of heat for each kilowatt of power it consumes. This is setting off some massive BS alarms in my head. Why is this not violating conservation of energy?
- voisin 4y agoHeat pumps rearrange existing heat in the environment, they don’t release it chemically by burning which is inherently <100% efficient.
- RC_ITR 4y agoThe wording is bad. It’s moved the equivalent of that energy. Technology connections did a good video on this. https://m.youtube.com/watch?v=7J52mDjZzto https://m.youtube.com/watch?v=7J52mDjZzto
- MoreSEMI 4y agoThis just means that you are moving heat energy from one resovoir to another. The total amount of energy the system releases is the energy moved AND the energy used to move that energy. COP is calculated by dividing the amount of heat moved by the energy used to move that heat. In short no violation.
- klyrs 4y agoThis is a common headscratcher in the heat pump space. They're taking advantage of a thermal gradient to get more out than they put in. Very much like driving downhill, as I understand it. If you put an air conditioner into a closed system, you can't beat Carnot efficiency. But if you're allowed to dump/absorb heat to/from the environment, the coefficient of performance measures the heating/cooling on the control side versus energy input -- which is allowed to go over unity. https://en.m.wikipedia.org/wiki/Coefficient_of_performance https://en.m.wikipedia.org/wiki/Coefficient_of_performance (I'm no authority here -- I only bought a heat pump and had the same reaction as you)
- stephen_g 4y agoIt’s cheating! The extra energy comes from the environment. It’s much easier to steal the heat energy out of the outside air (or out of the ground in colder climates, because it stays warmer) than to create the heat yourself. Producing heat can only be COP=1 if it’s 100% efficient, but you can use the same amount of energy to move three, four, even five times as much heat to or from the outside (moving heat the opposite direction is the way air conditioners work).
- gnicholas 4y agoHow does this compare to the energy efficiency/cost of gas-powered water heater?
- midoridensha 4y agoI don't see how you can compare energy efficiency between something powered by electricity and something powered by natural gas. They're two entirely different energy sources. The electric one doesn't involve putting more CO2 into the atmosphere, at least directly. And cost is completely variable, as electric and gas prices both vary wildly depending on location and time (gas became much more expensive in the last year).
- BlueTemplar 4y agoTypically much better efficiency since a gas heater is only 100% efficient, maybe up to 200% relative efficiency if the electricity comes from a faraway gas turbine. Cost difference is going to vary by an order of magnitude (and more) depending on the local conditions : https://news.ycombinator.com/item?id=34242237 https://news.ycombinator.com/item?id=34242237
- deleted 4y ago[deleted]
- vlovich123 4y agoWould this work to replace the compressor and refrigerant for refrigeration? Fridges that last need less repair and have nothing to leak when they do need repair would be pretty neat.
- ordu 4y agoThere is helium inside. Very leaky. But, I think, you mean that helium is non-flammable and do not do any environmental damage.
- KSteffensen 4y agoThe article doesn't state why they are using helium. Could the same be accomplished using some other cheaper, less leaky gas like N2? I'll speculate that since it's compression and decompression (as opposed to phase change) that's being exploited, you need a small gas whose behavior is as close to the ideal gas law as possible. Smaller gasses are also more volatile and leaky though, so there is probably some tradeoff.
- Someone 4y ago> The article doesn't state why they are using helium FTA: Because helium remains a gas until -200 C, we can achieve higher temperatures inside our heat pump core N₂ boils at −195.8 °C, but that will be higher at 30 bar.
- jabl 4y agoA quick look at a phase diagram I found online suggests the boiling point would be somewhere close to -160C at 30bar. Hard to see how that would be a problem in this application.
- jabl 4y agoI would suspect that N2, being diatomic, has vibrational and rotational modes which would cause a bit of inefficiency in the cycle. Would be interesting to see how much.
- system2 4y agoUntil someone shows me a very detailed video how this works I wouldn't put it in my house. It looks like a nuclear bomb.
- user-extended 4y agoAlso, you just _know_ people would just defer maintenance on this.
- ClumsyPilot 4y agoBut high-pressure cylinders of propane do not?
- system2 4y agoWho said I have propane tanks at home?
- buf 4y agoIs this the same tech used in James Webb telescope?
- once_inc 4y ago> Fun fact is that the JWST cryocooler operates on a similar principle (although the implementation is quite different). as per u/alexose in this thread.
- UberFly 4y agoEvery time a story like this pops up I find myself solely scanning comments for the critical flaw in the technology. Pavlovian dashed hopes response.
- apexalpha 4y agoThat's very interesting to see! The first time I read about acoustic heat pumps was when the Dutch governments' research arm spun off their start-up: Blue Heart: https://www.blueheartenergy.com/ https://www.blueheartenergy.com/ I had no idea multiple companies were pursuing this. That's great! If we can replace every gas boiler with a acoustic heat pump that can produce 70 degree water that will enormously speed up the electrification of domestic heating in Europe.
- kavalg 4y ago> The heat pump has a coefficient of performance (COP) of three to four, which means that it produces 3 kW to 4 kW of heat for each kilowatt of power it consumes. "We have the same efficiency as traditional heat pumps, but we have better modulation thanks to acoustic transfer" So, no advantage from an energy efficiency point of view. The ability to modulate is certainly good, but they don't provide figures. My inverter air-source heat pump can modulate in the 1-8 kW range. How much better are they? Maybe they are more efficient in the whole modulation range. I'd love to see figures. > Loyer said the heat pump can generate domestic water at up to 80 C. That could certainly be an advantage. Traditional R410, R32 based heat pump are happy up to 45 C and then they really start to feel the heat (pun intended :) ) > helium at a pressure of 30 bars I doubt that will last the stated 30 years. Gases such as hydrogen and helium are very hard to contain. Even the smallest crack or gasket problem will let it go. > Given that its core is filled with water, it works best as a water-source and geothermal heat pump Huge disadvantage IMO. Air source heat pumps are way easier and cheaper to install and service and work even in residential buildings. Most of the pumps I see installed around are air-source. They say that they can convert to air-source using a fan, but don't state what the disadvantages will be (e.g. wrt efficiency) >Equium claims that the heat pump system is completely silent, despite the use of a speaker to generate the acoustic wave. The level of noise is reportedly lower than 30 dB – the equivalent of a whisper. This could be a big advantage in residential areas. Big air source heat pumps emit a lot of noise from the compressor. > Equium is now conducting field tests for its thermos-acoustic heat pump. It expects to launch it at the end of 2023 Wold love to see some MSRP figures. Interested in early adoption in Bulgaria, Greece and the region (EU). My overall opinion is that factory made air-source heat pumps are overpriced compared to an AC unit with the same output power. That is why lots of people over here do a conversion by replacing the refrigerant-air heat exchanger with commercially available plate refrigerant-water exchangers. This however voids the warranty of the AC unit and you have to do some custom electronics to convince the AC unit that it is still and AC unit, while still providing the desired water temperature (mine works best in the 33-38C range, but my whole heating system is sized accordingly).
- himinlomax 4y ago> I doubt that will last the stated 30 years. Gases such as hydrogen and helium are very hard to contain. Even the smallest crack or gasket problem will let it go. Might be slightly easier than usual in this case because it's self-contained. It's not a reservoir that needs connection to the outside.
- danuker 4y ago> produces 3 kW to 4 kW of heat for every kilowatt of power it consumes So, not too different from typical heat pumps. Ground-source heat pumps are especially effective.
- tecleandor 4y agoAlthough it feels like a nice value for a first model in the market. I find interesting that's very silent, and has a nice range of work temperatures. And the "no refrigerants" part too (although it needs some helium, though). No info about the price.
- nraynaud 4y agofunny, I read the same thing, and had the optimistic view that maybe this is not a scam, they are not claiming crazy numbers. I suppose that since scientific machines use this apparatus, their design space has been explored in great details.
- kibwen 4y agoI remember reading about thermoacoustic devices 20 years ago, probably from the following article: https://www.popsci.com/scitech/article/2004-05/chilling-sound-waves-not-freon/ https://www.popsci.com/scitech/article/2004-05/chilling-soun... I think the reason that they haven't seen adoption isn't that they're a scam, but rather because they're more expensive than traditional approaches (not quite sure why, or by what margins). However, since our attempts to replace freon with ever-more-exotic refrigerants seems to inevitably fall face-first into environmental disaster, it's possible that a non-greenhouse-gas approach could be regulated/subsidized into existence, if it's not too much more expensive.
- speleding 4y ago> hot water at temperatures of up to 80 ℃ > level of noise is reportedly lower than 30 dB If it can provide water hot enough for residential use, and be silent, then it's a huge improvement over existing typical heat pumps. It would no longer need an additional boiler to get the water temperature up.
- 4y ago
- conaclos 4y agoThe founder of the startup made a speech to TEDx [1] (in French). He is the son of one of the precursor researcher on thermo-acoustic. The speech gives some possible applications of this new technology. [1] https://www.youtube.com/watch?v=-soze8e2Quo https://www.youtube.com/watch?v=-soze8e2Quo
- mosquitobiten 4y agoI wonder if this tech has the efficiency of a turbine and if it could be used to extract power from nuclear fission.
- smolder 4y agoIt's awkward to compare this to a turbine. In a sense they're opposites, one uses mechanical energy to create thermal gradients, the other turns thermal gradients into mechanical energy. However while a normal pump is sort of an engine run backwards, the heating efficiency of a heat pump is because it's moving heat, not because it's efficient at turning motion into heat. Finding a way to run this device "backwards" would not make for a good generator.
- mosquitobiten 4y ago>turns thermal gradients into mechanical energy This tech does this too, you can see here: https://youtu.be/wg96lDw7sNw https://youtu.be/wg96lDw7sNw
- smolder 4y agoWow, interesting. I can't watch now, but thanks for the link.
- slim 4y agothe cringe level of that video is over 9000. it looks like a startup founder imitating a standup comedian imitating a tedx speaker (maybe he does not have an audience because of covid, that's why it feels awkward)
- was_a_dev 4y agoI wonder how efficient it is at lower temperature outputs. If we can see much higher COP at lower temperature gradients, then it would be even more impressive. A much larger COP at 20C delta would be more effective for heating in moderate climates.
- satya71 4y agoI wonder why Helium instead of much cheaper Nitrogen?
- reacharavindh 4y agoI was just quoted this week for a CO2 heat pump set up that promises 62 deg Celsius water output with COPs that are at a range similar to that of regular heat pumps. The details on this company are scarce, so I'm treading cautious. Claims COP A7/W35 (I can't tell what A7/W35 means) of 4.8! https://www.durocan.com/specificaties/ https://www.durocan.com/specificaties/ https://www.durocan.com/co2-heat-pump/ https://www.durocan.com/co2-heat-pump/ Curious if folks who know about heat pumps here have any opinions on this. EDIT: It appears to be a Dutch company (I live in NL) that has licensed the CO2 heat pump tech from an American company - https://www.smallplanetsupply.com/sanc02 https://www.smallplanetsupply.com/sanc02
- carry_bit 4y agoIt's only 2.8 at -8C though. The best heat pump on https://ashp.neep.org/ https://ashp.neep.org/ [1] has a COP at Max Capacity @5F (-15C) of 3.7 [1] https://ashp.neep.org/#!/product/56885/7/25000///0 https://ashp.neep.org/#!/product/56885/7/25000///0
- Oxidation 4y agoA7/W35 means at 7°C air input temperature and 35°C water output temperature.
- bklyn11201 4y agoThis is a popular recommendation from green-building advisors in USA. I ended up rejecting it and buying a more standard hybrid (heat-pump) hot water heater from Rheem because of a) cost, b) plumber familiarity, c) payback time
- bronson 4y agoWe installed a Sanco2 on our house a few months ago. It's been performing as advertised so far. Impressive little unit. It was 7X the cost of just replacing the gas-fired heater. However, we turned the space the previous heater occupied into a much-needed pantry, significantly reduced pipe runs, and removed a source of combustion from inside the building envelope, which made up for the cost difference. Happy to answer questions.
- anovikov 4y agoLOOL this is the best prank i read in months. Now they will get funding offer by some fat ass government-sponsored EU fund and then publish this as a warning on how you can steal almost infinite money by riding green hype and bullshitting people who didn't go to high school but were put in charge of million euro decisions.
- anovikov 4y agoCome on people they are even giving you dead simple hints to make this as laughable as possible, mentioning a "Hi-Fi (High fidelity)" speaker - as if anything but a single-frequency acoustic wave might matter here.
- orestis 4y agoI haven’t seen a mention so far, but 30 bar pressure isn’t that big. Scuba diving uses helium (wellC helium and oxygen) at up to 250 bar (in small cylinders, 10-12liters) with no issue whatsoever. The cylinders aren’t even that big or heavy (for a heat pump).
- t43562 4y agoI do wonder why we have odd situations like a fridge inside a house that's using energy to keep stuff cool because the air in the house is being heated to keep people warm because it's cold outside....... And of course that we're leaking heat in various ways such as the output from sinks, showers or baths and in the form of stale air but a heatpump cannot scavenge from these. It would seem logical to have some sort of "temperature management system" which could move heat around from the various points to make use of whatever natural sources and sinks were available at that time of year.
- sagebird 4y agoIn the same spirit- a home has dozens of power bricks converting AC to low voltage DC. You would think a central high quality unit could do that… though an obvious drawback is additional wires to snake around…
- maherbeg 4y agoI would love for this. Low voltage DC has fewer, simpler requirements for building code and can be easily run through walls. Additionally, it would help a lot of the heat dissipation issues with LED fixtures. The only problem is the eventual voltage drop from long runs...
- kalupa 4y agocould almost treat it like an in-house network with a few AC/DC converter "hubs" scattered around where you need them, if the distances are too long, or the device load too heavy.
- rolenthedeep 4y agoI have been toying with the idea of converting my old telephone wiring to a 24/48VDC system for charging DC devices. A switch mode DC-DC converter is extremely efficient, and would be a net improvement over multiple disparate USB AC adapters. Unfortunately, it's just not that useful for my home. We don't have enough devices that charge concurrently to justify it
- Maursault 4y agoThis is awesome! No wait, helium would cause this super-efficient heat pump to cost more than it is worth and put a strain on areas where helium is needed, like MRI machines, which are already having issues due to the increasing rarity of helium. Couldn't they have used argon or nitrogen instead of helium?
- homarp 4y agoBlueHeart Energy ( https://www.blueheartenergy.com/ https://www.blueheartenergy.com/ ) from Netherlands also has developed a new heat pump that uses thermo acoustics. The technique consists in creating sound waves in a closed circuit to generate heat and cold.
- b112 4y agoWhy do I picture me walking down the street, and all around me heat punps are screaming? A cartoon of them actually screaming, is in ny head.
- teekert 4y agoMy neighbour has a large, fully electric house, no more gas, in a Dutch climate (winter ± 0-5 degC). I do feel that that property (which was very expensive) makes quite some noise indeed. His heatpumps, but also his solar converters in the Garden (where he has a small field of solar panels). And then he has some automated watering system that pumps from the canal into his garden... It's not loud, but it also not quiet. I don't like it.
- NegativeLatency 4y agoKinda fuzzy on how this works/what the tradeoffs are? Looks like it's creating a standing pressure wave and then tapping into the colder or hotter part as appropriate? Based on the diagrams it seems like it would need a radiator or something for larger surface area? Also curious as to how loud it is.
- stubish 4y agoPer the article: "Equium claims that the heat pump system is completely silent, despite the use of a speaker to generate the acoustic wave. The level of noise is reportedly lower than 30 dB – the equivalent of a whisper."
- hasmanean 4y agoIt’s been known for a long time, but sort of vanished off the radar for much of this century. I can only imagine it’s because it has applications as “mixture separators” as this webpage shows https://www.lanl.gov/org/ddste/aldps/materials-physics-applications/condensed-matter-magnet-science/thermoacoustics/index.php https://www.lanl.gov/org/ddste/aldps/materials-physics-appli... and so it could be used to enrich uranium (in the form of uranium hexaflouride gas), in a more robust way than the stupid legacy centrifuge technology. Thus all the interesting research on it must have been classified.
- arsalanb 4y agoIt uses the acoustic wave to expand and contract pressurized helium, and then conduct heat created from the subsequent pressure oscillation. Source: https://www.pv-magazine.com/2023/01/02/residential-thermo-acoustic-heat-pump-produces-water-up-to-80-c https://www.pv-magazine.com/2023/01/02/residential-thermo-ac... Which I just noticed was posted a few hours ago, here: https://news.ycombinator.com/item?id=34233719 https://news.ycombinator.com/item?id=34233719
- twobitshifter 4y agoSame question about how loud it is. Wikipedia says thermoacoustic engines work at 180db, which is the sound of a pound of TNT being detonated 15 feet away.