How can we make air conditioners more efficient? [video]
youtube.com
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PS: Also scroll compressors are substantially more energy efficient than rotary and various means of staging is even more efficient yet.
Have they said this is their strategy?
There are IP licensors (like ARM and the Fraunhofer Society) that sell licences to their IP without trying to force jurisdictions to adopt their technology.
> Incumbents will resist choosing to continue with current public domain technology
This would depend on the pricing of the IP licences and the competition within the market. If the licences are cheap enough and the market competitive enough that using this tech would provide an advantage, then incumbents would license it.
A lot of IP boils down to an idea that you could describe in an elevator and a few good engineers could turn into a product in a few hours to a year.
ARM sells things that represent... thousands? hundreds of thousands? of engineer-years. You can't just whip that up in a short time, it totally makes sense to pay someone else for their trouble to make something... but if you wanted to and had a billion dollars to spare, sure you could do it yourself.
The problem with "I thought of it first" IP protections is the phenomenon of simultaneous discovery. A whole lot of ideas just have their time come, and tend to have multiple people working on them and coming to similar results in short periods. Making this a race and letting the winner sell out to groups that either want to extract rent out of the idea or to hide it in a safe to prevent competition for 30 years is not conducive to progress.
One was a method of texting that didn't require looking at the phone, the other was a way to display lo-res graphics data without pixelation.
Oh that's easy, every phone before iPhone could do it - you need a) a physical keyboard, and b) a soft real-time OS. Tactile feedback of physical buttons + stable UI configuration with learnable delays = you could learn to operate the phone without taking it out of your pocket.
:)
Joking aside, what was your invention? Could you link to the patent?
Patent 7812993 Lossy method for compressing images and video
Patent 7711748 Method and apparatus for simplified access to online services
Patent 7028033 Method and apparatus for simplified access to online services
Patent 6897977 Lossy method for compressing pictures and video
Patent 6850782 Wireless device with vibrational communication capabilities
Patent 6657647 Controlling the order in which content is displayed in a browser
Patent 6418323 Wireless mobile phone with Morse code and related capabilities
AFAIK, none of these have been made use of. Though every time I see banding and blockiness in video, I think "they should implement triangles!"
At the risk of forever poisoning myself for related work, I guess. Whose bright idea was with that "you look at it, and you and everyone you know is now liable for 3x more damages for accidental infringement" law?...
Mine, obviously. All my ideas are Bright ideas.
The patents may have expired, anyway. One of the reasons I did the patents was I was always pestering people with those ideas, as I wanted someone to implement them. So they said "patent them, which will get the ideas out there."
The graphics one was pretty straight forward. Instead of dividing up the picture into rectangles, divide it up into triangles. Set a color for each triangle based on an average of the color pixels in it. Then, smoothly shade the rendering of the triangle based on the colors at each vertex. This will prevent any banding or that ugly blockiness. The number and placement of the vertices depends on the where the complexity in the image is, and of course would be adjustable.
The browser one is to have the browser rendering prioritize where the mouse cursor is. Great for slow connections.
I can imagine this working. Kind of like CW for HAMs, except with a 3-state switch and couple dozen more layers of abstraction between you and the wire :). I wish my Morse code wasn't so rusty though - and it makes me wonder, are there better text encodings that could be used for such purpose?
The method for texting without looking I described was only limited to writing, but it's also something I've done in practice before smartphones, in particular on a Sony Ericsson K800i. This was possible because of good-quality keyboard (and joystick), and good UI decisions. I don't know if they put an actual soft-realtime OS in there (I suspect so), but all the UI delays were always the same - so I naturally memorized sequences like "unlock, menu, texting, wait ~0.5 second for it to load, open thread, type in message, send". It probably takes teenage-level or business-professional-level of use to get that kind of muscle memory, though.
> Instead of dividing up the picture into rectangles, divide it up into triangles. (...) This will prevent any banding or that ugly blockiness.
Is the insight here that a triangle-based subdivision like this will make areas of detail not align on horizontal/vertical lines, unless the underlying image has its details aligned on a band? Or am I misunderstanding this?
> the insight
The vertices will be on pixel addresses. The edges of the triangle will have no discontinuities themselves, and the triangles sharing an edge will have no discontinuities. Hence, no banding or blockiness. A naive renderer would just render the colors of the triangle as a straight linear interpolation. A more advanced one could look at the adjoining triangles, and render it so the first derivative would also be zero across the line. I.e. curve fit it.
The selection of where the vertices go would likely be best selected where the colors are shifting fastest, i.e. an edge in the picture.
The neato thing is one could render a low res image on a high res display and it'll still look good. You wouldn't have these stray pixels scattered around the text like jpg does. The other neato thing is more vertices can be put in the complex areas of the image, rather than wasting bandwidth on the parts of it that are smooth.
Progressive sharpening of the rendering also works, as more vertices can be added at any time.
I have a faint suspicion that your familiarity with finite element models had something to do with your choice of triangles.
I've done finite element models, but they were pretty unsophisticated.
I was alluding the fact that barring boundary effects hexagonal tessellation and equilateral tessellation are essentially the same.
Wow, this threw me back. :) Indeed this was not only possible, but actually easy. I don't think it took a lot of effort or any conscious effort even, actually, the UI was so good, but most importantly there were no unpredictable delays and no unpredictable inconsistencies!
Why is modern software so bad in comparison? Sure it can do more things, but it does them worse. The interface of everything is constantly changing for the unfounded whims of designers who simply think "this looks prettier to me", things are not laid out logically, adverts permeate the interface of most products from phones to TVs...
PPS: Also the efficiency of a heat exchanger cycle has very little to do with the individual losses of the compressor components. Engine losses matter at the compression ratios you see in a combustion piston, but at the scale coolants run at (especially ones like in an AC that involve a phase change) it's almost noise when compared with the fundamental thermodynamic limitations. You can do a little better for sure; 33% lower friction losses seems reasonable.
But you can't do much better: the linked article is surely not talking about 33% better overall cooling efficiency, that sounds insane to me.
One bit of reasonable efficiency gains to be had is by switching refrigerants to an R22 analogue. R22 is banned per the Montreal Protocol as of 2020.
However, R22 has thermodynamic properties that make it more efficient than the standard refrigerant of today's residential and small commercial units, R410A. This is particularly as the heat of the atmosphere being rejected into rises with some Coefficient Of Performance (COP) differences in the 10% range.
https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=86088...
There are some analogues to R22 without the ozone damaging properties that share or exceed the the thermodynamic performance of R22. R407C is one that comes to mind, but there's a handful that can be retrofitted or purchased new.
However, a trade off is that generally a newer Energy Star unit will be significantly more efficient than an older R22 unit. My point with the R22 is that the industry will slowly move towards some of these other refrigerants because of their better thermodynamics.
I thought the issue with SawStop wasn't that the licensing was bad but that nobody was willing to take on the liability.
ie. If someone cut off their hand with a table saw, it was settled law that it was their own fault. If someone cut off their hand and the SawStop didn't fire, the manufacturer now had a gigantic liability.
Bosch came out with a superior design that doesn't use a brake at all, but were barred from selling it in the US because it infringed SawStop's patents.
Yeah, that's bad. When you resort to lobbying, you're no longer on the good side of the ledger.
https://www.swnewsmedia.com/shakopee_valley_news/news/educat...
However, I don't find forcing everyone to have it by law to be particularly palatable.
I will tell you, however, that it goes off about once a month like clockwork and, as far as I can tell, it hasn't yet fired because someone was about to get injured (this is a good thing--it means our people aren't being stupid).
It's a $100-$200 hit every single time it fires. So, we have an ongoing expense of about $1500 every year for SawStop. That's a new saw every year.
Should that really be forced on people?
I will absolutely fight you on this tooth and nail.
1) I don't want anyone to get into the habit of turning off safety features. Ever.
2) If the material can be cut on that saw without the SawStop, it should be able to be cut with the SawStop. If it can't, the fault is with SawStop, not the user.
I'm happy to pay the extra money for the extra safety. However, I will NOT allow you to blame the user for the fact that SawStop has not uncommon failure modes.
If you turn off feature you are back to your regular saw - hopefully you use a stick etc in all cases because as you note replacing cartridges is expensive.
One thing I like, it'll put feature back on automatically for the next time machine gets turned on.
You also have to wait for the blade to come to a complete stop before touching anything or you will fire the system. This can be annoying when you have the motor turned off, retracted the blade, and start setting up your fence only to have the system fire because it wasn't quite stopped.
Was there a sticker on something that was slightly metallic? Oops.
I'm happy to have a SawStop on my saws, and I would even recommend it. However, given how often it false fires, I'm not sure I would mandate it by law.
Or have a noncartridge saw brake on the saw, when you come off saw for more than 3 seconds put some light pressure on to slow it more quickly.
I think a fair number of false fires are from this rather than the "wet wood" worry.
$18K for a bottle of milk for a baby etc (trauma activation fees are crazy).
I was merely pointing out that saying you would never buy a sawstop for whatever crazy reason (ie, other companies wouldn't pay them the $3-$10 or whatever) seems a bit ridiculous.
If you have a fair number of folks using the saw, have them touch materials to saw first with saw off to get a read on it or list the ones not recommended.
That's a foundation of democracy, really: the right to petition the government. I think you might want to re-examine your view a bit.
Adopting a policy is different from having them mandate what people buy.
Hey, have people buy epipens and keep one at the school for each kid with allergies. Then later we will raise our prices 1000 percent. That's not influencing policy, its fucking people all the way to the bank - with government assistance.
FANG has a phalanx of former electeds and staffers paid to hustle their former colleagues. To defend their grift and dismantle civil society. Grist for an endless torrent of outrage porn.
While pendants will argue both me and FANG are "lobbying", petitioning our governments, our respective efforts hardly seem comparable.
Sawstop dropped blade below table. Bosch also dropped blade below table. So the invention was very fast acting sensing and then dropping blade. Sawstop added brake.
Sawstop ALSO did a brake. The brake made a pretty reasonable difference in terms of damage.
Plenty of youtube videos exposing this saw.
"SawStop uses a different mechanism to drop the blade, but also employs an aluminum brake. In our testing on both top and front strikes, the blade stopped with less damage to my hand than Bosch’s Reaxx."
The design was not superior and the infringement was not based on a brake or lack of one. The infringement was because of copy of the skin contact sensing / blade drop technology as what were called underlying elements. I think the case may still be ongoing though? This one went a long while.
And "not superior" is subjective. If the SawStop tech has enough false triggers and destroys as many blades as it apparently does based on what I've read (probably depends on material being cut), the increased cost almost certainly isn't worth it unless you're a high school shop class.
Meanwhile there wasn't even a mention of the sensing technology.
They basically tried to license it to the other saw companies.
The other companies said hell no. We have the market.
So sawstop started building their own (great) saws. They really are pretty to very high quality. The saw stop feature is also very effective.
It's so effective that if you are running a woodworking shop in a school, or ever want to let your kids use your saw, or have staff using your saw, you really owe it to them to ALWAYS buy a sawstop.
I've worked with a few owners who took the approach you did. Inevitably someone loses a finger - and after the dust settles and folks ask why they didn't put this VERY simple and not that expense solution in place - they usually regret it. Either they feel guilty for chisling on some $ and having someone lose function in their hand or if they are here in CA they pay out BIG TIME for their stupidity.
The license fee was going to be around 3% of wholesale (so about $3 on a $100 wholesale saw that goes for $200 retail). I think he came very close to licensing to ryobi?
Anyways, if you think $3 for potentially incredibly QOL saving tech is too much for an inventor that actually invented something (and tested on his own finger) then I don't know what to tell you.
That said, once someone's parents (if you run a woodshop in a school) or employee sues you - you may start valuing this invention a bit more.
The poster wanted to punish inventors for inventing. If that isn't a perverse incentive I don't know what is.
Please try reading what I wrote again.
Done.
Do you disagree that your writing says "the onus for lost finger is on SawStop"? Your writing seems very clear to me. I do not know why you are confused.
If some safety feature is judged too important not to have, as it is common in cars, the government steps in and makes it mandatory, but it doesn't mean there are no more licensing fees. At best, the licensing fees are limited to a fair price.
There's a difference between the cost to provide something and the license fee. Note the Moderna licensed its covid patents for $0.
> a fair price
What's a fair price? What is the rule that says one party is greedy and the other is reasonable?
https://en.wikipedia.org/wiki/Reasonable_and_non-discriminat...
Almost always those 0 cost licensing agreements are just PR stunts.
> On the other hand (!), maybe the onus for the lost fingers is on SawStop for demanding those licensing fees.
Also Walter:
> What's a fair price? What is the rule that says one party is greedy and the other is reasonable?
https://www.forbes.com/sites/douglasbell/2019/08/13/60-years...
Sometimes companies and individuals think that it's wroth losing financially for the sake of wider safety.
Are you seriously suggesting that they should just work for free?
You can send in your activated cartridge to sawstop - if it was skin activated then they may replace it for free.
If you are concerned about a trip you can touch blade to piece with saw off and it'll tell you if would have tripped. Or do a first cut with system off. Or if you have a wet piece turn it off.
That said if you have a nail or something in piece there are situations that could trip it for sure.
It's no surprise that sawstop can make a nice saw for 4 to 17x the price of competitors.
The other manufacturers would have had to immediately stop selling and possible have pulled all the other saws off the market. For liability reasons, you can't sell a line of saws that chop off fingers next to a line that doesn't. You're basically admitting the former is defective.
Or maybe you're right and we'll see an "admission of defect" suit sometime soon.
Saw Y doesn't have safety features and you use it at your own risk of injury. Saw X will stop cutting the moment it detects a body part. You also use it at your own risk of injury.
I'd think the opposite is true - you can't sell a $250 saw that won't cut someone's finger off next to a $200 saw and expect it to sell. No one thinks it'll happen to them... otherwise Saw-stop's own line of saws would dominate the market. Some people will pay the premium, but I'd bet that most will not.
Not one had ever said "I would commercialize <x>, but for the patents", nor have any said "I would stop doing innovation if patents ceased to exist".
I concede that there are some field where it might make sense (eg pharmacology), but most of the time, patents are a tax -- hugely expensive for small innovators and weaponized by mega-corps.
Further, in times of crisis (eg COVID or war with radar), patents are suspended for certain topics to promote speed of execution. We are at that point for climate change & energy efficiency.
I would love to see patent fees based on income level, and the more you get; the more they cost.
(It's entirely expected, if you think about it - a big company employing skilled specialists doing actual[0] engineering is bound to become a patent mill, as those workers have to invent their way out of new problems.)
I suspect that this might be the primary way patents are applied for and awarded, and it's different from the usual narration, that patents are either small inventors wanting to ensure the market rewards them for their hard work, or evil megacorps buying them up as a part of peace-through-MAD balance with other evil megacorps.
--
[0] - Traditional, "trad", not-software engineering. I know this is just a stereotype, and this[1] series of articles does a great job debunking it, but... well, I haven't fully internalized these conclusions just yet.
[1] - https://www.hillelwayne.com/post/are-we-really-engineers/; thanks 'Twisol for bringing it up (https://news.ycombinator.com/item?id=28192650).
I would think most of this stuff would have prior art...
I think tech based on magnetocaloric cooling is one option. There was a company I was following a years ago (I've since forgotten the name) that was researching advanced thermoelectric cooling technologies that would be offer much better performance than peltiers.
I am curious. What explains the success of Microsoft Windows as the dominant "technology" for PCs and laptops? That's not due to "intellectual protection rights" is it? I am not a software engineer, just a display engineer, would I be correct if I alleged that "IP regimes" are hamstringing operating system progress? My gut instinct is no, that would be an absurd claim. Perhaps equivalent to me claiming that "IP regimes" are hamstringing search engine progress? I am genuinely interested to find out what people think about this.
Yes, IP regimes are definitely hamstringing operating system progress. https://en.swpat.org/wiki/NetApp%27s_filesystem_patents goes into some details about why Linux doesn't have automatic transparent instantaneous backups like the NetApp fileserver I was using a quarter century ago.
The company probably doesn't want to sit on their IP for 30 years and not yield any profit. How does that benefit them.
They'll try to bend some arms, and if this fails, they're most likely to drop licensing prices until they meet market demand.
And yes, there's demand for efficient AC. I mean, come on.
So there's always a trade-off. You pay for this or you pay for that. And if its energy, you have to consider the material and energy supply chains or you are probably bullshitting people and yourself.
Ultimately an air con is a heat engine so Carnot's law applies. No possible magic beyond what thermodynamics allows.
ALL TOO MANY "inventions" summarily . You even have UC Berkeley getting into the con-game with the Water Seer (which claims violates thermodynamics). You'd THINK UCB wouldn't ever push physics-violating ideas but NOPE. A stain on the engineering school reputation!
The design described does seem to have fewer moving parts, which is good. But the advantage of linear vs rotary motion with respect to forces seems sketchy. Field strength in the linear system is likely to vary across the travel and would still need to be synchronized to the alternating current to prevent motor stalls. (Edit 50 of this comment: this effect is actually illustrated directly in the video here: https://youtu.be/2TFiL5BM3ss?t=348 Imagine the field lines directly correlate with force applied, and mentally plot the quantity of field lines over time as you watch the animation. Turns out it looks precisely like the force chart of a rotary compressor.)
The primary advantage of this pump, to me, seems to be reduced weight/complexity and lower friction losses. For it to operate with low starting load it would likely need to essentially vibrate its way to full travel (confirmed at 7:47 in the video), something rotary compressors can’t really do. If you try to restart rotary compressors too quickly after stopping, the high head pressure will stall the motor. This causes it to effectively be a dead short minus winding resistance, pulling much more current than average (known as LRA or locked rotor amps) with no cooling. This will heat the motor quickly until it thermally trips or burns up. This is why you will frequently see restart delays in A/C systems.
For what its worth, scroll compressors have been around forever and share some of these advantages, but aren’t dominant in the industry because of the additional complexity in manufacturing. They have an additional advantage of somewhat continous output pressure, which *significantly* reduces ambient noise and vibration. They also have fewer moving parts and are generally more reliable.
All of these advantages convey to standard air compressors by the way, something I'm a little surprised they didn't mention.
https://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=...
I assume that this is pretty common in trying to improve linear motors - I am trying to get my hands on a small one to drive an air pump and it's just inscrutable to me.
I love the idea of low hanging fruit in every dimension of technology, but the reality is that linear pumps have been around for quite some time and aren't dominant in any high (sales) volume application that I'm familiar with. That tells me there are likely some tradeoffs here that are not being explained. Vibration would be one obvious area, but could be handled with a harmonic balancer or an additional pump operating 180 out of phase (unfortunately increasing cost/complexity).
The other potential issue is that the motor needs to be built for the application for the most part. With rotary compressors, you can incorporate pulleys to gear the system up or down in accordance with the cheapest motor you can put to use. With this system the motor is the pump, so it's harder to add some kind of lever to gear it up or down. (This is less applicable to small A/C systems which tend to use hermetically sealed compressor systems, but for larger systems this can come into play.)
Now Copeland may choose to build these, but they are going to have to build the motor vs. buying them from one of hundreds of companies that build AC motors to spec.
Now one of those companies might decide to build these linear motors, but they are going to have to license the IP to do so, putting them at a distinct cost disadvantage vs. standard rotary motors. They are also going to be a sole supplier for some time, something manufacturers are very wary of unless it's a major differentiator. These are likely to cancel out.
As you say, they are vertically integrated, they are well set up to produce the full stack of the technology. They also need compressors (for air conditioning, and at least in their trucks for other systems), that need to be compact and energy efficient. The technologies at play (pressurized fluids, eletric motors and magnets) are all very familiar to them.
https://cleantechnica.com/2020/08/03/teslas-octovalve-enable...
> In the Tesla Model Y, the heat pump was a true engineering marvel. Elon admitted on the podcast that he has a trophy rack of impressive tech his teams have come up with in his bedroom at home. The new printed circuit board (PCB) for the Tesla Octovalve was so impressive to Elon that he added it to his bedroom trophy rack.
It's probably pretty easy to swap out the compressor for a new design, fundamentally all compressors do the same thing.
Every house in Japan with a small scale septic system has a linear pump for injecting air. This may sound niche but in fact large parts of the tokyo metro area are not on centralized sewer systems. Thus there should be at least 10M+ houses with such motors running continuously in Japan alone.
The pumps run 24/7 without maintenance for well over a decade.
Which also suggests there are bigger reasons not to use such pumps in AC. As any Japanese manufacturer will know of such pumps.
Yup! This reminds me of a similar pitch from a few years ago. When a Kickstarter went live for a small, quiet window air unit called Noria, people signed up in droves, thinking a startup in Philadelphia had somehow solved a physics problem that Johnson Controls and the companies it's sucked up over the years somehow whiffed on. This new device would chill the whole room, it would be quiet, compact, and most importantly, it wouldn't be heavy. It would easily slot into your window, and store under your bed in the cooler months when you don't need it. They raised nearly $1.5M USD in 2016, and in the last year finally started to deliver window units that were ... big, heavy, and noisy.
The physics of heat exchangers are very well established. It's wise to take any wild claims of higher efficiency with a massive grain of salt - someone missed something in their equations and it's going to come out during manufacturing.
It was amazing to me how small the screws were for say, a shopping mall unit.. and how PRECISE the machining was.
The math behind the profiles was insane to, it was a 'self generating' curve.. You calculated a point on the curve, and that was fed in to generate the next point. Generating a new profile shape was a HUGE process... Wonder what it would be like with today's computers :-P
You could then move the table anywhere you wanted in X/Y, cover the display, and he would bring it back to 0.0000X by eye :-)
He actually went to some institute in Sweden that did ultra-accurate measurements to show them how he did it. I think the 'trick' was, he moved the shadow till it was just past the blueprint, and back it off till a sliver of light shone thru, rather then trying to 'walk' the shadow up to the blueprint..
Neat stuff - but I decided on a tech career when I was mucking out the Holyroyd mill and he turned the cutting pumps on :-P Being drenched in cutting oil convinced me I liked computers better :-P
(Superchargers are simpler, but cost ~10% engine power to drive)
Inverter based heat pumps and ACs that are already available on the market today have low LRAs as a consequence of their ability to operate at continuously variable speeds.
It's hard to verify more on the design. They offer a lot of explanation and tests, but no independent review is given. Main question on YouTube about scrolling compressors (used in newer fridges) is anwered a bit vaguely [2].
The patent portfolio page is very grandiose [3] but doesn't care to link anything. A quick search doesn't turn up much to do with air or fluid compression, only "Magnet device comprising stators and translators" [4] and similar, which don't mention compression at all.
[1] https://www.magtor.tech/who-we-are/
[2] https://www.youtube.com/watch?v=2TFiL5BM3ss&lc=UgxHEJkjlZ9fZ...
From their ‘Who are we’ page[1], their Director of Production “oversees the production of the Magtopressor Demonstrators”, so not really production per se.
The focus on worldwide patents and number of patents in the videos is also noticeable.
Overall I like his content, he is usually fairly technical and realistic about the prospect of things he cover. He has also has done some deep dives in e.g how to calculate levelized cost of energy to help analyse/compare different new inovations he showcase on the channel.
But sometimes I guess it can be slightly too pop-sciencey, reminding me (both in a good and bad way) of the glossy science magazines of my youth. Extrapolating barley lab bench-viable results to full scale production, with very optimistic timelines etc.
We have to stop pretending we are going to save the day by making AC units (or any other thermal machine) a few percentage points more efficient — because this is peanuts and nowhere near the amount of efficiency needed to grant humanities survival on earth. The best AC unit is the one that you don't need.
We need to look at where big gains can be made, and improving the thermal efficiency and air circulation of buildings holds a lot of promise. You don't have to go full passivhaus, even just improved insulation, double/triple-layer glass, sun shades and well-placed foliage to provide shade can net much larger improvements than some tweaks to AC design.
Where I live (Central Europe) air conditions are the total exception. Adding AC to flats is rarely ever done, thermal insulation much, much more often, even in old buildings. Maybe this is because the winters also get cold so thermal insulation has the extra pro of reducing the heating bill.
The power put into the system by the motor is constant throughout the entire revolution. It follows that, since the piston moves slower near maximum compression, force increases (since power = force * speed). This is also intuitively the case: You need much more force to push back the piston (against a constant motor torque) near its apex because the moment arm of the crank shaft gets smaller and smaller.
Yes, at the maximum compression point the force is not well-defined. In a sense it is infinite (you could not actually turn the rotor by pushing on the piston). But certainly not zero.
I'm struggling to understand what the creator might have meant instead. It's not work or power (which, again, is constant). The rotary motion works, if anything, in favor of the system, as the force gets larger with compression (past the midway point). Is there some quantity I'm missing? Maybe something to do with gas laws?
I'm also skeptical about the illustration with the additional magnets to contain the magnetic field lines. As drawn, that would not work for AC as the magnetic field would be the wrong way around half the time. Maybe they just use extra iron to shape the field - but that is extremely far from being innovative and more like electrical engineering 101.
It could well be that I'm missing something, but overall this video had multiple strange explanations that lower my confidence in the overall accuracy of the reporting...
Using the inertia of the plate mass at the end of each stroke is clever though.
I'd have thought a rotary electric motor connected to a rotary compressor would be quieter and easier to design the bearings for, and would operate in a more steady-state regime, so be more reliable. You also don't need the valve where the fluid from the two sides meets up, avoiding that efficiency loss.
I think the latest fridges (which are also air conditioners) use rotary compression.
Modern fridges and industrial electric motors have had "soft start" circuits in them for at least a decade. The start-up current thing is a non-issue.
I didn't quite understood how that new design is more reliable or serviceable? The closed compressors are literally zero maintenance. Also, the vibrations of that thing will tear itself apart quite fast, just look at their own promotional video: the pipes themselves cannot possibly last long with such vibrations: https://youtu.be/2TFiL5BM3ss?t=471
Attempt at direct linking: https://www.youtube.com/watch?v=2TFiL5BM3ss&lc=UgzdQZ_jgrbde...
--- Context (post by Ed Williams)
Most residential (and many commercial) AC units, refrigerators, heat pump and such use scroll compressors. Yes, they have a startup in rush, but I'd be interested in seeing efficiency of this tech versus current scroll compressors.
--- Post by "Just Have a Think" (the creator)
Response from Magtor CTO : There are many types of compressor in use and the industry somewhat specialises within particular technologies based on the power requirements, type of applications, manufacturing costs, end product costs, etc.
Regarding efficiency of scroll vs reciprocating compressors, not all sources agree but the trend is that scroll compressors are at least slightly more efficient, based on operating conditions…
There is this interesting white paper from Schneider Electric, “The different types of cooling compressors” https://download.schneider-electric.com/files?p_Doc_Ref=SPD_... and I also found this study: “Comparison of hermetic scroll and reciprocating compressors operating under varying refrigerant charge and load” at https://docs.lib.purdue.edu/cgi/viewcontent.cgi?referer=http...
> Most modern compressors and pumps use rotary motors to shove a fluid from A to B inside a chamber, but rotary motors can lose as much as 30 percent of their output when they're asked to convert their rotary motion into linear motion required by compressors and pumps. That conversion is done by a crankshaft and once a crankshaft is in the system you get some friction losses but more importantly you get diminished efficiency because you're only getting maximum shove force in the middle of the piston stroke. The start and end of the stroke are both dead points where zero force is available to do any useful work. In a compression task you really want the maximum force to be applied at the end of the stroke not the minimum force. Overcoming these inertia forces every time the motor starts up requires a big spike in power demand which can be as much as five times the motor's normal operating consumption.
> The technology that Magtor have been quietly developing for over a decade now is a magnetically driven linear motor that completely eliminates the need for a crankshaft and achieves far higher operating efficiency as a result. Here's how it works. A fixed electromagnet stator sits at the centre of the motor. On either side of that are magnetic plates that are connected to each other via a shaft that runs through the middle of the stator. That connection effectively turns the two magnetic plates into a single moving part. As a voltage is applied across the electromagnet its polarity attracts the magnetic plate at one end and repels the magnetic plate at the other end. But because it's an electromagnet its polarity is changing 50 or 60 times a second as a result of the alternating current flowing through the copper windings. [...]
> You also avoid that costly power spike at start up as well. Because there's negligible mechanical inertia to overcome, as soon as an electrical current is applied the movement caused by magnetic attraction and repulsion can get going instantaneously. And on top of all that, Magtor have developed a very smart additional element that optimizes the motive power provided by the magnetic flux of the system. [...] In this working example a magtopressor is connected to a five-litre tank of air. Magtor's tests have shown that their device, which is smaller and lighter than a traditional reciprocating piston air compressor, can pressurize a cylinder 38% faster while consuming 33% percent less electricity.
(emphasis added)
They run in a continuous way rather than with a piston. And my understanding is that most A/C compressors use them.
I don't think that's right. Why would diminished force when the piston is turning around lead to a power loss?
You can literally buy fish tank air pumps that use this exact mechanism [3].
The only thing mildly novel here is that they're driving it both directions via magnets & more complex drive electronics. Most of the commercial versions just use a steel piston, and single-direction actuation because they can then run the electromagnet directly off mains AC to get the cycling action.
1: https://www.techmagpm.com/en/linear-piston/ 2: https://www.nitto-kohki.eu/en/operating-principles-en/linear... 3: https://www.jehmco.com/html/central_air_pumps.html
Google "Sawafuji Swing Compressor".
For air conditioning, fridges, ground source heat pumps.
Even if it works I'm not going to buy a new fridge just for that though. Manufacturing a whole new fridge will be worse for the environment than running this for many years especially on green power.
However when it does go, it would be nice to have.
However the bottom temperature of the near-by Baltic Sea is -4°C. I know this because I was hunting for halibut.
There is already a separate system which refrigerates government offices from the Baltic Sea.
I would suggest is to use the system to cool all homes by using the central heating system. All you need is lower is temperature to 15°C in those pipes.
It is supposedly 30-40% cheaper than current ACs and being solid-state stack it's definitely more efficient(Not sure how it compares with the calimed efficiency of Magtor).
And we need to switch to pressure change rather than phase change systems.
That pretty much means the compressor needs to be built into the 'condensor'.
The closest we get to today is two stage compressors - where you compress a bit, cool the gas, then compress some more. But we need to get to 50 stage compressors - where we compress slightly, then cool, and repeat.
Also, we will need to switch out the pressure regulating orifice for a turboexpander to recuperate the energy which would otherwise be lost letting something high pressure become low pressure.
All these add complexity and cost, but ultimately will be needed to make efficient enough systems when energy is more expensive in a carbon-free world.
There are downsides to this: wasted tap water and hot sewers. Probably certain municipalities should disallow such air conditioner water heaters except to make hot water for showering and bathing.
Also see: https://www.hotspotenergy.com/air-conditioner-water-heaters/...
The true breakthrough here will happen with solid state gas compressors.
Solid state compressors already approach, or pass 50% efficiency — something only possible in very large, staged, centrifugal compressors for large AC systems. A solid state compressor, unlike that, will be equally efficient regardless the size.
https://www.energyrating.gov.au/sites/default/files/2020-06/...
Adding a second hose to a single hose AC can improve effiency by around 100%... This is because portable air conditioners are tested differently to other air conditioners.
"The DoE found the addition of a second duct that uses outdoor air to cool the condenser would yield an efficiency gain of 103 per cent for a retail price increase of around US$8 (from US$534 to US$542)—a price/efficiency ratio of 1:103 (i.e. a one per cent increase in price provides a 103 per cent increase in efficiency). Because double duct portables are no longer available on the Australian and New Zealand markets, suppliers are unable to communicate their benefits compared with single duct products. The existing energy efficiency regulations on portable air conditioners appear to have had the perverse effect of removing the more energy efficient product (double duct portables) from the market, while encouraging the marketing of single duct portables, by allowing unverified claims to be made about the effectiveness and efficiency of these products. This RIS considers options to resolve this perverse situatio"
"The single duct portable’s performance information is likely to have been obtained from a test that measured the cold air produced. Fixed air conditioners, conversely, are tested to measure their cooling effect on an enclosed space. While a single duct portable may blow cold air onto a person, if its performance was tested in the same way as a fixed air conditioner, it could have a net heating effect on the room it was supposed to cool."
Yes, the crankshaft confers the greatest mechanical advantage at the top and bottom of the stroke; that's an excellent observation. The position vs time plot of a crankshaft follows a sine wave, the velocity (as a derivative of position) follows a cosine, and the acceleration available from a constant input torque follows the derivative of the position, again a sine wave. However, this available force does not meant that the exerted force at the top of the stroke is high, as it needs a reactive force to work against. This force is mostly provided by the fluid pressure, rather than by a velocity-dependent force like friction.
At the top of stroke, the gas is not under significant compression, so it takes minimal force to move the piston. Near the bottom of the stroke, when the gas is maximally compressed, there is maximum force on the piston. When the pressure exceeds the output of the compressor, the air begins to exit through the check valve. Another complicating factor is that there are typically two pistons on the same crankshaft, so as the piston returns the gas remaining in the cylinder is working with the motor. The final and most complicated part of the problem is that the whole point is that the gas being compressed is not an ideal Hooke's law spring where PV = constant, it's undergoing adibatic compression, where P x V x gamma = constant, where gamma is the specific heat of the refrigerant, and the temperature changes through the compression.
You can improve your intuitive understanding of these relationships with an ordinary bike pump and the bike's pedals. When the pump is fully up, there's little resistance, you can feel the force increase when it's almost at the bottom, and you can feel and hear the air going into the tire for a short length of the stroke at the bottom. Likewise, pushing vertically on the pedals (avoid pushing forward or pawing backwards) does the same thing as a crankshaft.
"33% more efficient" is repeated in several company documents and videos, but I can't find the baseline for that measurement.
(Edit: But only until the unit that combines both the sides and makes it back to DC (still using analogy) back again)
https://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=...
if you buy a airconditiiner that only cools (or only heats) it can be aything from 3 to 5 times more efficient than a reverse cycle type.
Coming from UK / Europe I'm always surprised by the number of people in the US and of course Asia that are totally dependent on aircon.
That's going to be quick, easy and politically viable.
Building in excessively Dubai for example seems crazy to me.
People seem to be living in crowded cities just because they're forced (jobs are nearby, apartments are generally cheaper than apartments because they're generally smaller, etc).
Desert environment should definitely be super high density and possibly largely underground in my opinion. Things don't seem to be moving that way, though.
That said, I'm glad people play around with new designs. That's how innovation works. I just wish investors would be satisfied with "we're trying a reasonable alternative design to look at benefits" rather than requiring "the old design is a dinosaur, and our design solves every problem under the sun"
At best, this wastes power. At worst, this wastes power and means the one room you actually want to cool doesn't get cooled properly.
I've lived in a unit with a door in the same room as a split system and it was amazing. The room would become completely cool in around 5 minutes, then the compressor would shut off and run for maybe 2 minutes every 15 minutes or so to maintain this cool temperature.
Definitely sounds regional, but also we air condition the entire house so we aren't winning the efficiency war here.
Central HVAC exists, but 90%+ homes don't have them.
It's not as convenient and comfortable (one common problem older houses have is that there is no AC in kitchen) but the energy cost difference compared to the norm in the North America is night and day (the houses are significantly smaller here too).
In Australia you can get ducted systems, but at the residential scale it's both more expensive and less efficient than split systems. So houses will often have larger split units (5 - 10kW heat/cool capacity) in the main living areas and then smaller ones (2.5 - 3.5kW capacity) in all the bedrooms. Sometimes you have a multi-head system with one outdoor compressor unit and two or three indoor units.
This is even the case for large apartment buildings (often have a separate AC compressor for each unit), but most office and commercial buildings have central AC.
I've spent some time trying to turn a portable AC unit into proper AC solution during the recent heatwaves over here in Poland, and the doors were a problem for me, not a solution. For example, I work in a study, and my wife continuously moves back and forth between kitchen and the living room. That's already 3 rooms to cool, 4 if you count the corridor (which shouldn't cause you a thermal shock every time you navigate it). Which doors are best closed or open depends on whether our kid is home. E.g. when she is at home, my study doors are closed, and I get to cook inside.
I'm on a rental now, so I can't duct the apartment the way I'd like (also the reason I bought a portable unit), but on the next apartment, I plan to either have a split system with a terminal in every room, or a duct system for supply air from the AC unit.
I understand that for large homes, some rooms may not see much use during the day - but in apartments, I can't imagine such a thing, unless you're living alone.