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Power Technology

Cutting-Edge Technology Could Massively Reduce the Amount of Energy Used For Air Conditioning (wired.com) 75

An anonymous reader quotes a report from Wired, written by Chris Baraniuk: The buses struggling in China's muggy weather gave [Matt Jore, CEO of Montana Technologies] and his colleagues an idea. If they could make dehumidification more efficient somehow, then they could make air conditioning as a whole much more efficient, too. They headed back to the US wondering how to make this happen. [...] "I have here 50-gallon barrels of this stuff. It comes in a special powder," says Jore, referring to the moisture-loving material that coats components inside his firm's novel dehumidifier system, AirJoule. This is the result of years of research and development that followed his team's trip to China. The coating is a type of highly porous material called a metal-organic framework, and the pores are sized so that they fit around water molecules extremely well. It makes for a powerful desiccant, or drying device. "Just one kilogram can take up half or more than half -- in our case 55 percent -- of its own weight in water vapor," says Jore.

The AirJoule system consists of two chambers, each one containing surfaces coated with this special material. They take turns at dehumidifying a flow of air. One chamber is always drying air that is pushed through the system while the other gradually releases the moisture it previously collected. A little heat from the drying chamber gets applied to the moisture-saturated coating in the other, since that helps to encourage the water to drip away for removal. These two cavities swap roles every 10 minutes or so, says Jore. This process doesn't cool the air, but it does make it possible to feed dry air to a more traditional air conditioning device, drastically cutting how much energy that secondary device will use. And Jore claims that AirJoule consumes less than 100 watt-hours per liter of water vapor removed -- potentially cutting the energy required for dehumidification by as much as 90 percent compared to a traditional dehumidifier.

Montana Technologies wants to sell the components for its AirJoule system to established HVAC firms rather than attempt to build its own consumer products and compete with those firms directly -- it calls the approach AirJoule Inside. The firm is also working on a system for the US military, based on the same technology, that can harvest drinkable water from the air. Handy for troops stationed in the desert, one imagines. However, AirJoule is still at the prototype and testing stages. "We're building several of these pilot preproduction units for potential customers and partners," says Jore. "Think rooftops on big-box retailers."
Montana Technologies isn't the only firm using cutting-edge technology to make air conditioning units more efficient. Rival firm Blue Frontier has developed a desiccant-based dehumidifying system using a liquid salt solution, with installations in various U.S. locations, that links to a secondary air-conditioning process and regenerates desiccant during off-peak hours to reduce peak electricity demand.

Then there's Nostromo Energy's IceBrick system, installed in California hotels, which freezes water capsules during off-peak hours and uses the stored coolth during peak times. This system can reduce cooling costs by up to 30 percent and emissions by up to 80 percent, according to Wired.
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Cutting-Edge Technology Could Massively Reduce the Amount of Energy Used For Air Conditioning

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  • I just hope this doesn't turn into one of those ads where an 18 year old inventor stereotype builds an AC that can cool a room down in seconds.

    • by SeaFox ( 739806 )

      ...an AC that can cool a room down in seconds.

      I just saw an ad for one of those on YouTube earlier today. Only instead of being an 18-year-old it was an ex-NASA engineer. I watched the ad long enough to confirm from the ad's content the miraculous, small, battery powered device was just another version of a swamp cooler.

      • If you could cheaply dehumidify the air in humid climates though, then you could make swamp coolers work in places where they usually don't.

        Does "new device"+swamp cooler have a lower TCO than coolant-loop A/C? That's the question. I live in an environment where swamp coolers already work, but people have been installing mini-split units because they provide both cooling in the summer and a heat pump in the Winter. The Winter weather doesn't spend much time below freezing, so heat pumps are good here. T

        • by ceoyoyo ( 59147 )

          Does "new device"+swamp cooler have a lower TCO than coolant-loop A/C?

          Maybe the one mentioned in the summary that captures the water then expels it from the dessicant when electricity is cheap. I doubt dessicating the air then evaporating water right back into it would be efficient without some kind of shifting like that.

          • The way I could see doing it would be to have the option of directing outside air through the chamber as well as inside air. Specifically, the air coming off of cooling the condenser, so it is extra hot.

            Basically: Dehumidifying: Incoming inside air is directed through the chamber before it reaches the cooling radiator, absorbing the moisture.
            Regenerating: hot air from the condenser, thus capable of holding more moisture, is directed through the chamber to grab the released water vapor and continue outsid

            • That's basically how they describe it working, on a roughly 10-minute cycle between two separate chambers before they switch roles and continue.

              The magic pixie dust is literally the dust they figured out how to make is the desiccant used in the two chambers that has an absorb/empty temperature that are close enough to use HVAC waste heat directly.

              The trick will be scaling it down and packaging it to be useful for residential use where the 'hot bit' is 50 feet away from the 'cool bit' for many installs inste

              • Iâ(TM)ve heard of similar prototype before that had a continuous slowly rotating desiccant discs that were recharged with the waste heat continuously. This was years ago. Such a disc could be so large that a larger section could be unloading than being loaded by humid air.

            • by ceoyoyo ( 59147 )

              That works for a regular air conditioner. A pure evaporative cooler doesn't have a condenser.

              • Well obviously, but, well, by the time you're evaporating enough water for serious cooling, you'd be faced with issues of finding a heat source big enough to regenerate this stuff enough to keep the air dry enough for people AND continued effectiveness of evaporative cooling.

                A bus, especially an ICE one, has all sorts of possible heat sources for that, but at some point running a pump isn't that bad, giving you traditional AC. And if you're in a fixed location with, say a good amount of solar, you could ac

                • by ceoyoyo ( 59147 )

                  The poster I was replying to was specifically asking about drying air in humid climates to make an evaporative cooler work, not generally about the subject of the story.

        • Agreed about swamp coolers. They make it clammy if you're not constantly bringing in dry (and hot, of course, because it's summer) air. I tried to install a mini split in my place but I'm not brave enough to do my own electrical work at the box, though I replace outlets and such all the time. I couldn't stomach the thousands the electrician wanted as daylight robbery to do the electrical work. It's also unfortunate the mini split inside units are so large - I live in a house with very small rooms. I'll f
          • I'm not brave enough to do my own electrical work ... I couldn't stomach the thousands the electrician wanted as daylight robbery to do the electrical work.

            You confess having neither the competence nor courage to undertake high stakes work (those stakes being your home and you and your families lives), yet begrudge those with the knowledge and experience to do this work safely a decent wage?

            • Why would I begrudge the a good wage to those who could get it? No, what I begrudged was $5000 price for JUST THE UNIT that could be purchased for $1000 at the time. The installers were from a town about 50 miles away (I live very rural) and I suspect really didn't want the work or, if they got it, they were going to get paid very, very well. Everything in life is choices.
              • Preach. I'm also in the sticks and you either pay out the wazoo for licensed contractors, roll the dice with "handymen", or DIY. I DIY whenever I can. Some trades are better than others. It's relatively easy to find a good plumber here. It's difficult to find a good electrician who doesn't charge those exorbitant prices. One thing you learn the hard way is that even using a licensed contractor is no guarantee of good work. Some of them are just a cut above the unlicensed. I've seen some wild shit he

      • Every summer, some yahoo, often someone trying to show off they are "country", shows off that they stuck a fan into a bucket of ice, and it makes cold air. Some people even do things like add heat exchangers so the wet air stays in the bottom of the bucket. However, those things are either swamp coolers, and 100% worthless in most of the US (Arizona, yes. California, yes. Houston and eastward... no.) Or they are just banking on the relatively pitiful heat capacity of ice.

        However, there is actual stuff

    • There's some science worth exploring here. If you walk past a window AC unit you'll hear water splashing around inside it. That's condensate, water pulled out of the air. Here in Tennessee in the summer the condensate from my central air unit will overflow an 18 gallon trash can in a day. Call it 70 liters * 55 mol/l = 3850 moles multiply that by 40 kJ/mol = 154,000 kJ per day in the summer just condensing water. Divide that by 3600 to put it into stupid energy units aka kWh = 42 kWh per day * 9.8 cen

  • awnings? (Score:5, Interesting)

    by jjaa ( 2041170 ) on Tuesday July 16, 2024 @06:42PM (#64631159)
    nah...
  • Pretty coolth (Score:5, Interesting)

    by byronivs ( 1626319 ) on Tuesday July 16, 2024 @07:18PM (#64631219) Journal

    Causes cancer in 3, 2, 1...

    • You have a beautiful mind!
      Sony and/or GE will probably sponsor a scientific finding showing it causes Cancer combined with Legionnaires’ disease.
      Wow am I tired, and hot, but not in a good way.

    • I second⦠new wondrous miracle material, a nano fibrous composition that can coat the insides of walls and increase the thermal resistance to incredible levels. Aka asbestos
    • but which novel new battery tech can power these?

      Do I need this week's revolutionary breakthrough battery, or do I have to wait for next week?

      I presume that I can't use the ones I stockpiled last week?

      snark aside, this "new wonder powder" sure sounds like the regular battery breakthroughs.

    • Causes cancer in 3, 2, 1...

      Could be.

      However, dehumidified air is considerably less healthy [nih.gov] for humans, and, I would guess, pets. Indoor humidity levels are generally suggested to be kept around 45%. For you musicians out there, that's also the target to prevent adverse warping and resonance behaviors in wood instruments. Feeding really dry air into an air conditioner — which will further dehumidify it, because cooling air causes moisture to condense out on the cold evaporator coil — seems like a

      • ... because cooling air causes moisture to condense out on the cold evaporator coil â" seems like a poor idea to me.

        Dehumidifying air first saves a lot more energy if you don't have to condense that liquid water by cooling it.

        https://en.wikipedia.org/wiki/Enthalpy_of_vaporization ...and its enthalpy of vaporization, 40.65 kJ/mol, is more than five times the energy required to heat the same quantity of water from 0 ÂC to 100 ÂC...

      • by tlhIngan ( 30335 )

        However, dehumidified air is considerably less healthy for humans, and, I would guess, pets. Indoor humidity levels are generally suggested to be kept around 45%. For you musicians out there, that's also the target to prevent adverse warping and resonance behaviors in wood instruments. Feeding really dry air into an air conditioner â" which will further dehumidify it, because cooling air causes moisture to condense out on the cold evaporator coil â" seems like a poor idea to me.

        The problem is humi

  • by pixelpusher220 ( 529617 ) on Tuesday July 16, 2024 @07:23PM (#64631235)

    "The bus company couldn’t work it out. Some days when its buses merely crawled along the streets, their power consumption would go through the roof. The reason why was a mystery."

    On hot summer days, in an enclosed metal tube in the sun, they couldn't figure out what was causing increased energy drain.

  • The company ownership is largely Venture Capital, with a rather impressive maze of companies reltaed to it bith as direct investors and IP owners. I was a little confused by why the elaborate shell structure and largescale Media presence from a podunk company from nowhere, MT (aka Ronan). Then I noticed Max Baucus is on the board and it all started making more sense. If anyone is curious how politicians use influence to make money do a little digging on this and it'll start making sense.
  • by pusoozer ( 8606671 ) on Tuesday July 16, 2024 @08:15PM (#64631357)
    Rather than simply drain the condensate from the room to the outside, have the fan kick it up into the external heat dissipation coils, cooling them, and gaining much efficiency. Westinghouse did this in the 60s with their small room air conditioners, and produced a unit which cooled much better than the competition's equivalent model.
  • Odd choice of words (Score:5, Informative)

    by Frank Burly ( 4247955 ) on Tuesday July 16, 2024 @08:43PM (#64631393)

    "Just one kilogram can take up half or more than half -- in our case 55 percent -- of its own weight in water vapor," says Jore.

    I'm assuming that this statement holds true for the material regardless of the quantity. Like, the material can absorb about half its weight in water, regardless of whether you have an African Swallow or VW Bug's worth of the stuff.

    It looks like silica gel can only do 37%, so this is an improvement. IIRC, this guy used calcium chloride in his desiccant-based AC with interesting mixed results [youtube.com].

    • Those kind of dessicant based cooling systems are more common in large scale cooling/heating and also in trigeneration powerplants, with more exotic chemicals than the YouTuber's road salt. Lithium hydroxide comes to mind.

      In the end it comes down to how much energy is required to make the desiccant dry again.

      Either AirJoule needs less energy to dry, or it's advantage is smaller size making it suitable for home use.

  • But at what cost? (Score:5, Interesting)

    by khchung ( 462899 ) on Tuesday July 16, 2024 @08:44PM (#64631395) Journal

    This system can reduce cooling costs by up to 30 percent

    If this system is anywhere near cost-effective, it would have been added to the production line of all existing air conditioners (especially for datacenters!) already, or they could create add-ons to existing systems and sell like hotcakes.

    The fact that they talk about electric buses (which is such a small market) rather than datacenters or commerical buildings is a big tell that their system most likely either cannot scale, or cannot operate for longer without maintenance.

    • You discount the inertia in how many companies' procurement process works, they want true and tested products preferable from a big well known brand. They rather watch others test out new technology first to evaluate if it fits them.

      Add to that, nobody is going to throw out perfectly functioning systems before they are worn out and AC-system have a lifetime between 5-20 years depending on the local climate and the load.

    • Re: (Score:3, Interesting)

      by nickovs ( 115935 )

      If this system is anywhere near cost-effective, it would have been added to the production line of all existing air conditioners (especially for datacenters!) already, or they could create add-ons to existing systems and sell like hotcakes.

      By that logic, anything that reduced costs should have already been invented. Lots of things seem hugely obvious after the fact, but go un-invented for decades.

      The fact that they talk about electric buses (which is such a small market) rather than datacenters or commerical buildings is a big tell that their system most likely either cannot scale, or cannot operate for longer without maintenance.

      Maybe the fact that they talk about busses it's because they had the idea while sitting on a bus, rather than while sitting in a datacentre. It seems likely it has utility elsewhere but when you build a product you have to start somewhere, and most products start by being marketed in the space where the inventor first saw an opportunity.

      • by khchung ( 462899 )

        If this system is anywhere near cost-effective, it would have been added to the production line of all existing air conditioners (especially for datacenters!) already, or they could create add-ons to existing systems and sell like hotcakes.

        By that logic, anything that reduced costs should have already been invented. Lots of things seem hugely obvious after the fact, but go un-invented for decades.

        I did not mean this tech should have been invented already, I meant they would already have many customers lined up if they have anything economically effective, i.e. their tech costs less than the energy saved, with the current high energy prices, they should have no trouble finding customers in Europe.

        • If this system is anywhere near cost-effective, it would have been added to the production line of all existing air conditioners (especially for datacenters!) already, or they could create add-ons to existing systems and sell like hotcakes.

          By that logic, anything that reduced costs should have already been invented. Lots of things seem hugely obvious after the fact, but go un-invented for decades.

          I did not mean this tech should have been invented already.

          Perhaps you should have.

          The ‘new’ technology is basically dehumidifying air for an air conditioner. Also known as what desert environments and Mother Nature ‘invented’ a few thousand years ago. Finding dry air isn’t some mystery. Go to the places that sell humidifiers for fun and profit.

          In fact, I’m still wondering how this A/C ‘breakthrough’ wasn’t proven long ago in desert environments.

    • by Kaenneth ( 82978 )

      The highlighted point is the weight ratio. They are probably targeting vehicles because the extra weight of an AC unit affects performance more than on a fixed building.

    • > If this system is anywhere near cost-effective, it would have been added to the production line of all existing air conditioners (especially for datacenters!) already

      They're called energy recovery units, or sometimes total enthalpy units, or sometimes a very specific implementation is called an enthalpy wheel. It's been a thing since the 1960s.

      The cost for the efficiency gain was rarely justified until the last decade or so, with energy prices that keep going up and mandatory efficiencies getting more

      • To add, datacenters should be humidified. Low humidity air something something triboelectric effect something something sensitive expensive electronics that are supposed to be reliable therefore not liking dry air. Something about air and silicon on opposite ends of the tribolectric series and normally humid air not normally being a problem because it dissipates the charge. Something else about computers being 100% efficient as resistive heating elements leading to a conditioned room being quickly dehumidif

    • If this system is anywhere near cost-effective, it would have been added to the production line of all existing air conditioners (especially for datacenters!) already, or they could create add-ons to existing systems and sell like hotcakes.

      The fact that they talk about electric buses (which is such a small market) rather than datacenters or commerical buildings is a big tell that their system most likely either cannot scale, or cannot operate for longer without maintenance.

      I've seen this system before - there was a guy on youtube who built a desiccant air conditioning system in his garage a few years ago. He explained how it all worked - basically you're using waste heat to pull the humidity out of the air rather than trying to cool it down with the air.

      The main reason this isn't widespread in commercial situations is that most buildings/data centres etc are essentially airtight systems. Once the air inside has been cooled down, you don't have to deal with humidity anymore. T

    • by RobinH ( 124750 )
      Once you cool down the air in a building, the humidity is out of it and you don't have to do extra work to get rid of more. Where this technology would help is when you're introducing humid outside air into the space, typically through a heat recovery ventilator (HRV) or just by regularly opening the doors. An HRV would be a lot more efficient if you could dry the outside air first before it comes in. In the case of a bus, with doors opening all the time, not to mention fresh air vents, and the humans th
  • Cooling the air is what takes energy in existing heat pump systems
    Dehumidification is a free bonus

    • Re:Nonsense (Score:5, Insightful)

      by Smidge204 ( 605297 ) on Tuesday July 16, 2024 @10:29PM (#64631507) Journal

      That depends entirely on how humid the air is. There's a metric called the Sensible Heat Ratio which describes the portion of your cooling power that goes to actually changing the temperature of the air, because condensing the water vapor is a constant temperature process (being a phase change and all).

      The only times your SHR = 1.0 is if you are not cooling to/below the dew point. In practice this basically never happens in human occupied spaces because the relative humidity goes up and it becomes extremely uncomfortable very quickly even if the thermometer on the wall says it's cooler. (Also, mold problems...)

      In a normal system the SHR is usually around 0.75, meaning about a quarter of the energy you're spending to condition the air goes to just removing the water vapor and not actually making the air colder. If you're processing a lot of outdoor air or a space with high humidity for some reason, SHR 0.5 is easily reached meaning you're now spending more energy condensing than cooling.

      There is nothing "free" about dehumidification. Second law out front should have told you.
      =Smidge=

      • If dehumidified air is so damn amazing for air conditioning, then can someone please explain how and why air conditioners deployed in VERY dry climates don’t already prove it daily, without this amazing new tech?

        We are pretending that very dry air conditions don’t occur naturally, or that dehumidification tech needs to deliver air with near-zero moisture content to work, which I seriously doubt.

        What am I missing here in the desert?

        • Also a desert dweller. You are not missing anything. However, having grown up in a much more humid climate where the dehumidifier routinely turned into a block of ice, they do have a point.

          It might well be more efficient to dry the air with their zeolite sort of thing, then cool it. It comes down to how much energy does it take to get the water out of the zeolite.

          Over all it's basically the same thing as pressure swing absorption to make reasonably pure nitrogen without the expense of a cryogenic plant.

          • Also a desert dweller. You are not missing anything. However, having grown up in a much more humid climate where the dehumidifier routinely turned into a block of ice, they do have a point.

            Lived from Alaska to Florida and many places in between. I certainly wasn’t arguing the benefit of dehumidifying air for the benefit of air conditioners. Dealt with plenty of ice blocks.

            I’m more questioning a ‘breakthrough’ in air conditioning when feeding an A/C unit dry air, isn’t exactly hard to replicate and prove this tech is actually a breakthrough. We should have been able to measure power draw and efficiency simply comparing the same air conditioner technology deploy

        • PS, relative humidity at the moment is 24%. Air temperature 85 F, dew point 44.

          Coolest and "muggiest" (by local standards) it's been all week.

        • > What am I missing here in the desert?

          The actual claims made, it seems.

          Also the fact that the majority of people don't live in the desert. That part is pretty important, because it means your personal experiences do not translate to the majority of other people's experiences.

          > then can someone please explain how and why air conditioners deployed in VERY dry climates donâ(TM)t already prove it daily, without this amazing new tech?

          They do. Again, if you understood the claims being made and had pro

    • by FeelGood314 ( 2516288 ) on Tuesday July 16, 2024 @10:29PM (#64631509)
      Air with lots of moisture releases far more energy that dry air. Water is bizarre. The heat of vaporization is 540 calories per gram where one calorie is the energy to heat one gram of water one degree (and the specific heat of water is the highest of any normal matter). A cubic meter of air has a mass of about 1kg. If the air was dry, cooling it 10 degrees C would release 10000 j of heat. If the air was 30C and 100% humidity and you cool it to 20C then 15g of water would condense releasing 34000 joules of heat. 77% of your energy you need to dissipate would be from the condensation of water.
    • No. The energy consumption in an AC goes to condensing water out of the air (latent heat of evaporation) and to cooling the remaining mass of air. You may be shocked to know how much energy is in humid air compared to dry air.
  • by Smidge204 ( 605297 ) on Tuesday July 16, 2024 @09:54PM (#64631453) Journal

    'AirJoule' has invented nothing new. Desiccant based dehumidifiers and enthalpy recovery systems have been a thing for decades. They're only using a more expensive material to do it.

    Blue Frontier also has not invented anything new. Ice storage for chilled water systems has been a thing for decades. Nothing revolutionary here.

    If you want to decrease your cooling energy consumption, insulate, seal, and shade your building better. After you've done that, use more efficient (e.g. modern) equipment...
    =Smidge=

  • Seriously? Is this technology from the C16th or something?
  • this could make the air to water machines more efficient too
  • could. or not.

  • "containing surfaces coated with this special material"
    Surfaces that are maximizing surface area while minimizing drag?
    https://www.youtube.com/watch?... [youtube.com]
    Advantix and others make liquid desiccant coolers where the liquid is sprayed down the chamber to create a whole lot more surface area without the drag of having a lot of surfaces. The liquid spray certainly slows the airflow, because physics, but it seems to be more efficient and requires less material. Plus the liquid can be transferred around for filterin

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