Revolutionary Air Conditioner!

hi you might be wondering what this is it is not an oil refinery this is a desiccant based air conditioning system [Music] we've already done a couple of videos on a thermal electrically cooled or Peltier cooled refrigerator and freezer and in that case because you can really well insulate the enclosure you can compensate for the low efficiency of the Peltier's and take advantage of some of the convenience factors but with an air conditioning system the problem is it's expensive to produce really good insulation for a large building and it's very expensive to try to retrograde engineer better insulation to existing structures so the name of the game with air conditioning systems is efficiency there is a industry term called cop or Co P or coefficient of performance and that is the amount of heat energy measured in watts pumped per watt of energy expended in the process and the higher the cop the more efficient the unit is going to be this system here is far more efficient than a typical compressor based phase-change air conditioning system and the working fluid in this case is water water is a remarkable fluid in that it consumes or it uses a tremendous amount of energy to change the phase of the water from a liquid to a vapor or from a vapor to a liquid it takes five times as much energy to take 100 degrees centigrade water and convert it into 100 degree centigrade vapor as it takes to take that same quantity of water and bring it all the way up from zero degrees freezing cold all the way up to a hundred degrees centigrade in the first place and conversely the same amount of energy is released when that water vapor condenses to a liquid so to take advantage of that what we are going to demonstrate here is the power of that phase change in water and I'm going to set up a little apparatus here to just show you how potentially powerful that kind of application can be okay what we're using throughout the build is some four-inch ID or 100 millimeter schedule 40 PVC pipe we have some piping here we have a elbow or tea fitting here and I've welded on the bottom of the teeth a small segment to create a reservoir for water here in the bottom as well as on the top I've connected a threaded fitting to this large diameter tubing and a neat trick for doing that is to take the fitting that you intend to connect to whatever diameter tubing that you're using you place a piece of sandpaper on it to form a curve and then just simply by drawing this back and forth about 30 or 40 times takes less than a minute you can grind a radius in here so that it will fit on the tubing and provide a nice tight seat what we did in the spray component here is that I fabricated one of these welded fittings with the curvature placed in it and then using a solvent cement I placed a piece of tubing on there and then when this was dry put a little bead of epoxy and pushed it onto the hole that I drilled in the side of this then I was able to weld a an elbow another piece of PVC pipe here in which I've drilled some holes a cap in which I drilled a hole to provide a spray nozzle to distribute the water that's going to be pumped up to the top of the evaporator in the base of this reservoir t-fitting there is a piece of mesh this is a nylon mesh that I've placed inside of the tubing what the purpose of this is is to keep these called bio balls anybody familiar with wet/dry filters in fish tanks or aquarium know that they're used to increase the surface area for the interaction of air and water there inert they're made out of you to nylon or polyethylene and if we fill the tube with this we're going to provide a larger area for the water and the air to interact so what I'm going to do now that the mesh is in there as I'm going to fill this up with a quantity of these bio balls and you can obtain enough of these to do this entire system each of these stacks has these bio balls placed in it to be able to do that entire setup here for about $30 and as I'll get into later there are other options and it's full enough for now and then we're gonna add the pipe and then I'm gonna keep adding them to get up near the top about now and then the nozzle will go up here on top and then to prevent any spray getting into the air that's going to be flowing out of here well add a few additional bio balls above the outlet from the spray now what I'm gonna do is I'm going to weigh this this entire structure here so we'll get a known weight for the components and I'll bring this over to this scale and we'll zero this okay now as you can see we have about four point nine five kilograms I'm gonna call this only four to be very conservative because they're not going to really involve the fan or the pump in this process plastic PVC polyethylene has about 1/4 the thermal inertia of water it takes about four times as much heat to warm a quantity of water as it takes to warm the same mass or weight of plastic so effectively we've got about one kilogram of water inertia here and what I'm going to do is I'm going to add two litres 1,000 CCS to the top of here okay now what we're going to do is we're gonna hook this up to a temperature meter and what we have in here is an inline temperature probe to measure the temperature of the water that's circulating in this loop and then what's going to happen is the temperature of the water will drop as it's being circulated through here and there's a counter current of air going upward and then what we're going to do is we're going to time how much temperature is actually lost so we have a given amount of thermal mass and we have a time and you'll be able to see on the power supply we have a number of watts used to accomplish this and then we'll be able to calculate what the top or coefficient of performance of this evaporative system is this is a baseline for everything we're going to do from this point on all right and then we're going to measure the starting temperature not the air temperature so let's turn this on about 15 watts temperature is measuring twenty point six degrees let's go you okay 14 degrees we've used 16 watts we've gotten a temperature differential of 6.6 degrees so the amount of cooling we got was 3000 cc's equivalent of water times 6.6 degrees so effectively we've gotten about 20,000 calories of heat removed from this water which is about 80,000 joules and we used 16 times 300 or about 5,000 joules so we have a cop with a system or a coefficient of performance of about 16 to 1 now a typical room air conditioner has a cop that's about 4 or 5 times worse I'll show you the little one that we have here mounted in the lab but you'll see that with this system you can do some pretty impressive cooling now for your skeptics out there you might say well yeah yeah this is just a swamp cooler you've converted temperature into a high humidity with a desiccant based system though you can fix that you can compensate for that if what you do is you place a desiccant material in front of the airflow so effectively you pull off humidity before you in reintroduce it you can bring the humidity down to near zero and then bring it back up to ambient without adding any additional humidity and get this high efficiency of cooling now one of the challenges though with desiccant based systems is that the adsorption that's with Addie meaning surface adsorption process decreases entropy and it releases heat so that the air that would come off of here to be brought into the cooling column would be warmed in the process you can easily deal with that though you can take that dry and warmed air and bring it back down to ambient by simply taking a couple of radiators and one radiator pulling the air through from here and the other one in a closed loop taking that air temperature taking the the heat out it only takes a watt or two to move enough air to be able to reduce the temperature here back down to ambient the other problem you have with a desiccant based system is obviously at some point the desiccant is going to become saturated it will no longer be able to pull water off and dry based desiccant systems have been around for dehumidification and even refrigeration systems and in order to use them what typically is done is they pack a large quantity of this material because it's not very efficient into a great big disk a perforated disc that slowly rotates in front of some wedge-shaped ducting and so through one say a hundred and twenty degrees of its of its circumference the one the air is pulled through dehydrated and sent to an evaporative column as the disc slowly rotates that moisturised or saturated desiccant it then moves in front of a hot air stream which then draws off or drives off the humidity and then as it moves to the third section in that in that rotation in a sealed system the heat is then allowed to be released the desiccant cools back down to ambient as it returns into the airflow the problem with those systems is to keep them efficient you want low speed air velocities and so with an inefficient absorbing material and with the desire to keep the ducts large this becomes mechanically very large very bulky and it isn't very efficient because solid desiccants aren't that efficient but there's a better alternative and that's what we're going to show you today okay so desiccants dehumidifiers and even refrigeration systems have used solid desiccants for for many years but very recently liquid desiccants have come to the fore as being a much more convenient and even more effective way of dehydrating air this Erlenmeyer contains distilled water this Erlenmeyer contains liquid desiccant now you might think this isn't some sort of exotic liquid but it isn't this is 35 percent road salt calcium chloride and water that's it it's almost free and its ability to DES kate is pretty substantial if I were to leave these two flasks in here for a week the level of the water would actually drop due to evaporation and the level of the desiccant solution would actually rise as it absorbs water from the atmosphere it would take too long for me to demonstrate that here so what I'm going to do is I'm going to place these in a warm bath and you're gonna see an interesting phenomenon occur over the next couple of minutes so we're going to attach this large diameter coupler between the two of these good enough and then I have some warm water and I put this in this basin so both flasks will be at exactly the same temperature there we go keep an eye on the sides now what we're going to do while this is going to demonstrate what's going on here I'm going to go through the overall flow and principles engineering behind this entire system and I'll kind of show you where things are going and how we're going to accomplish the the air conditioning in a in a practical manner all right so what's occurring here is each one of these three columns are almost identical in that they're filled with bio-balls they have the same flow patterns air is pushed in rises up water or desiccant pour down water pours down so their counter current evaporators dehumidifiers and desiccant refurbishers you'll see that there's a little radiator on top of a burner that provides heat so that the flow that's going to be coming up through here and measured at this probe is going to come to the top of this column and drizzle down through the bioballs as the air that's pumped through the bottom is rising up what this will do is this will dehydrate the desiccant solution that is being pumped up to the top when the fluid reaches the bottom here it will be dry it will be concentrated but it will be quite warm and so then this pump will pump this through to an evaporative cooler on the other side where a similar radiator like this is immersed in a water bath and where air being flowed by these fans through these evaporators will cause a lowering of the temperature of the desiccant which then will exit here and rise to the top of the dehydration column at this point the now cool and concentrated desiccant will drip down through here and then the fans over here will pump air that will then be dehydrated as it rises through the column it goes past a temperature probe through this loop here it's now dry but warmed by this process because as I said the desiccant desiccation process warms the air so when we pass it down through here into this box there is another radiator in here and this radiator is then hooked up to the second evaporative bath over there in a closed loop and so by going up and down in a sort of zigzag pattern through this radiator what comes out here is now dried and cooled this then will pass through a coupling here into the bottom of the final evaporation column which is what you saw demonstrated a little bit earlier and then the air that comes out of the top will be the properly air conditioned or cooled air what we're gonna do before I actually demonstrate how well this performs is I'm going to turn on the evaporative pre coolers over there and let them run for about 20 to 25 minutes because right now the water in there is at room temperature once I start the evaporation process there's a fair amount of water in there the temperature will drop down to an equilibrium temperature and that's what is going to be accomplishing the cooling of the desiccant as well as the pre cooling of the air over here there is a German company that has begun introducing desiccant based refrigeration systems and they've demonstrated a substantial improvement over regular phase change compressor based systems they are not incorporating this evaporative cooling stage and even so they've gotten a doubling of the efficiency over a regular air conditioner so this is something that we came up with that turns out it works very well and adds substantially to the efficiency of the system basically what's happening here is that in this unit we just have a fluid loop and the water is being pumped out of the reservoir and to these small PVC pipes that are running underneath the fans each of the pipes has a small hole cut right above where the evaporation is occurring so they dribble water down over these evaporators but substantially more water than is evaporated so the cooling effect on these evaporative wedges here then pours down into the desiccant into the liquid in the base and so the whole reservoir drops down in temperature but obviously that would take a little bit of time these fans are extremely low speed the total consumption of power here is about 3 watts for both of the evaporative coolers these pumps only use about a watt and a half in this case we have a radiator down here because we have to self contain or we have to contain the desiccant in the other unit we're simply taking that cold reservoir water and using it as a closed loop between the evaporator and between the radiator that's contained inside of the box and as you can see right now it's reading at about fifteen point three degrees and we'll give it about twenty minutes and see how much colder we can get this just by using evaporation and before I leave you I think we can take a look at what's happened to the desiccant if we left this here for a couple of hours we'd actually see a level change but you'll notice all the humidity that's condensed on the sides of this Erlenmeyer above the water level but no humidity here this is actually pulling the humidity in the air here into this container here that's why this is completely clean or clear and this one has a fog on the inside this stuff really works ok we've pretty much reached an equilibrium temperature here oh it's I've left it go for like an hour and a half and it's just not dropping anymore we took about a half hour to get here but I wanted to assure that so based on the room temperature and the cooling tray water temperature I've got a pretty good differential here for these pre coolers so what we're going to do is I'm going to disconnect this here and I'm going to move this mirror over here to measure the temperature of the heated desiccant in this tubing here and connect this probe up here to measure the outflow temperature from the dryer stack over here so put this over here like this there we go and then finally I have a temperature probe located up here to measure the temperature of the final column of air when it comes out I have a little anemometer that we're going to use to measure the air flow velocity out of here and I'm going to show you right now that the diameter on the output coupler here this is a six inch scale so it's about four and a half inches across here about a hundred and thirteen millimeters which is about one of a square meter so we'll be able with a velocity and the area to determine the actual quantity of air that's pumped through here and then we'll measure the temperature differential we can determine watts of cooling now a couple of additional caveats here if you look back here you will see a tube that connects the two reservoirs down here and the purpose for this tube is that even though the two pumps which are pumping the fluid of the desiccant out of the two reservoirs are identical and powered at the same voltages and even though I have these clamps to find adjust the flow to try to equalize it if it's not absolutely perfect over a period of time what will happen is one reservoir will drop at the expense of the other if I adjust it pretty closely all that overflow tube will do is take care of that little miniscule build up over time to keep the two reservoirs at the same level another interesting thing is if you look at this this radiator here has stainless steel tubing in it it's sister inside the bath in this evaporative tray also uses stainless steel tubing we need to do that because we're using a corrosive salt mixture in here and these things can be obtained on eBay or surplus we got this from a surplus laser but any kind of industrial equipment that uses DI water for its cooling will have stainless steel tubing and that's that's compatible with this mixture the radiator that I showed you before in here consists of aluminum simply because we're using distilled water between that evaporative cooler and this one in here so you can get a little bit less expensive radiator for this function over here now one of the things also is that these baths back here consume a fair amount of water in the evaporative process but that water does not have to be high quality water it shouldn't be sewage but effectively you can use grey water you could even use seawater for this as long as if a venture periodically you flush this so that the concentrating salt solution in here is flushed out you don't need to use expensive pure water for this evaporative function unlike the evaporative cooling stack at the very end over there which does need to use clean water because it's going to be getting into the air in your room so yeah they're gonna be consuming a little bit of clean water with that now another important feature is that these two stacks are dealing with saltwater and when you're blowing air through them you want to vaporize that salt water but you don't want to get the salt into the air so an interesting thing you can do to test that is you can take a little popsicle stick spray a little water on it like that taste it pine and then place it in the outflow from the stacks and what that effectively will do after a half hour an hour if you then take it off and taste it there should be no salty flavor to that you've been added no salt to the air now if that happens one of the reasons that might be is that if you don't have enough bio-balls or surface area to block any kind of spray from that nozzle at the top you can get water droplets or desiccant droplets into the air so by adding additional bioballs above there or adjusting the speed on your fans you can make sure that the salt doesn't get into the air once you've assured yourself of that there's another neat option and that is we're using calcium chloride in here which costs pennies but if you do elect to go to lithium chloride which is an even more effective desiccant it's about three times as efficient as this desiccant it costs a lot more you may spend twenty or thirty dollars to fill up a system like this it won't be consumed you won't waste money but it is more toxic and so you don't want to get that in the atmosphere if you're leaking any kind of salt into the air so that's important now what we're gonna do is I'm going to turn on the burner here we're gonna get this thing up temperature and then I'm gonna turn on the rest of the fans and the pumps and we're gonna see what kind of temperature we get out of this device now let's get this going we don't need much heat and then we'll turn on our pumps it's going to get loud now we're flowing the desiccant as you can see the bubbles rising through there doesn't have to go fast as the hot desiccant drives off the humidity with the counter current of air and if we've measured the velocity on the output here with the anemometer we can determine what kind of actual volume we've got flowing here so I'm going to hold this thing up here and see if you can see this upside down and I'll get an idea of what kind of volume is coming through here it's pretty good 143 129 and 43 it's probably about 135 or so so 1.35 which turns out to be about a sixtieth of a cubic meter or about 20 grams of air flowing so when we get the temperature differential across here we'll measure we'll multiply that by the number of grams of air and determine the actual wattage so let's go ahead and turn on our pumps get a temperature here okay this t2 is the temperature of the air flowing out of this column this may continue to drop for a little while because this water is effectively at room temperature so it's gonna take a little time for this to drop in terms of its equilibrium temperature as we saw with the previous step meanwhile we'll look at the power that we're using for the pumps we're using about half an amp at 6 volts so about 3 watts for the fans here we're using about 3/4 of an amp at 6 volts so about 4 watts so that's 7 watts over here for the pumps over there we're using about half an amp at 6 so a total of about 10 watts and over here we're using about 24 watts so we're using about 34 35 watts in order to be able to cool off this air which is really cold it works really nicely so if we figure that the room temperature here is 22 degrees centigrade and we've got this temperature down here at about say 11 degrees centigrade we have a drop of 11 degrees centigrade across this system with 20 grams of air that turns out to be about 220 watts of cooling with about 34 watts of input so if you do the math on this you figure that 34 into about what 220 you've got somewhere around 7 a cop of about 7 which is a little better than twice what we demonstrated with that air conditioner including all the additional fans and the pumps now one of the important things though is that the thermodynamic efficiency of this system is actually only about half that of that air conditioner over there and the reason being is that we haven't included the heating stage in the process this stage here will require about 3 times as much power as is being used by the electrical system here and therefore you'd get a cop of about half of what you get from that air conditioner but before you say well then you know what's the point the point is that we don't need to use expensive heat to do this if we burn say natural gas we can produce the same number of joules of heat for about 10 to 20 percent of the cost of electricity so running this kind of an air conditioner is still substantially more efficient cost wise than running a typical air conditioning system but you can go further you don't even need to use a consumable with the cost of one or two watts of pumping by one of these little solar heating pumps you could run this up to a solar heating panel on say your roof and do the desiccation heating with free energy from solar and when it's hot during the day that's basically when you want the air conditioner to be working and so therefore that would allow you to keep that same two to one differential over a standard system the German company that I talked about earlier is combining this kind of a system actually with a standard phase-change air conditioner and the elegance of that is that they're using the hot output from the air conditioner to drive the desiccation process and so by doing that what they can effectively do is they can remove the evaporative stage from this system in humid in humid environments the majority of the energy that's extracted by an air conditioner is not to cool the air but it's as a dehumidifier that's what all those droplets are on the coils in a standard air conditioner if you can effectively do the desiccation process with waste heat from your air conditioner you can effectively allow the air conditioner to just cool the air and their obtaining efficiencies of about two to one as well they are not using the evaporative pre coolers that we are so I have a suspicion that in that kind of a system we could probably boost the efficiency even higher in addition this kind of a system right here has the cooling capacity that would be about half what we need for a room as large as this layout but it is very easily scalable this PVC tubing is available in 100 millimeter 200 millimeter even 300 millimeter diameters and up to about the 200 millimeter size which is 8 inch these parts and pieces are still very inexpensive because this is mass-produced consumer grade material and consequently you could upgrade this substantially and improve the the size and the capacity but furthermore the pumps that we're using as low power as they are they only use about a watt and a half these pumps are about 20 times the capacity of what you need to simply dribble the liquids down these columns and so no matter how big you build this you really wouldn't have to add any additional pumping power furthermore the fans that we're using here are way way away far far away from optimal these axial fans are not designed to produce pressure they're designed to move large volumes of air with no pressure if we use a low speed centrifugal fan like the kind that you use for say a shop dust collector you can increase the pumping efficiency against the resistance of these these bio balls or whatever you use about two to two and a half times over what we're doing here so with an efficient brushless motor again scaling this up would improve the efficiency even further so the biggest expense that you might actually have in a much scaled system would actually be the bio balls we've got about thirty dollars worth of bioballs placed in here and in a large system that could represent a fair investment but there's another alternative if you take used empty water bottles and you crush them up put the lid back on you effectively have a poor-man's bio ball it's recycled trash it doesn't fit very well in the top of something this small but certainly in a larger scale this would be a very in a very cost effective way to provide the surface area that you need for evaporation there's about a hundred and twenty billion dollars a year spent on generating electricity and it's estimated at about ten percent of that or about twelve billion dollars a year is used for air conditioning of buildings and of homes and if you can double or even more than double the efficiency of air conditioners you could save as much as six billion dollars worldwide and all we ask is that you subscribe it wouldn't help if you link to the channel and the link to the video would really appreciate that but I hope you found this interesting and I want to thank you very much for watching and you have a wonderful evening [Music]

Channel: Tech Ingredients

Views: 1,559,339

Rating: 4.8972454 out of 5

Keywords: Air conditioner, Cooling, Cold, Desiccant, Desiccants, Desiccant based cooling, Liquid desiccant, Evaporative cooling, evaporation, air cooling

Id: R_g4nT4a28U

Length: 32min 50sec (1970 seconds)

Published: Wed Jul 03 2019

Reddit Comments

[u/Im_Seeking_Knowledge]

Tech Ingredients is easily one of the most informative and quality video channels out there. Tons of detail of the project in every video.

[u/versvisa]

Can someone with expertise in the area weigh in? If this design is more energy efficient and cost efficient than the compressor design, why is it not the "default" that everyone buys?

Air conditioning has been around for a long time. I would think that all design options have been explored and evaluated.

[u/jaydezi]

I love the speaker videos from Tech Ingredients. It's on my list of things to build

[u/prenderm]

This is awesome

[u/CowOrker01]

The cooling stacks remind me of the Bong Coolers that overclockers experimented with back in the day.

[u/pawza]

Did a little reading and here is at least my basic understanding. The desiccant strips the water from the incoming air. Which is then humidified ,dropping the air tempatures. The desicant is sent to regen where the water is driven off with heat. From what I have read 60 to 75c is the tempature need to regen the liquid desiccant. At which point he used an exterior swamp cooler to cool down the desiccant to below ambient tempature. The crux of this is that the desiccant system did less than 220 watts of cooling. I do wonder how this would compare to an ammonia heat absorption setup.

Here is a link to a similar setup and you can also look at the trane cdq. Use the same idea but to deliver dry air evaporator coil.

http://articsolar.com/solar-desiccant-cooling-systems/

[u/murdok03]

Just watched this through the recommended page, it's pretty nifty.

[u/asoap]

I really should be working, but this was way too fascinating to not watch right away.

[u/dirty_beard]

I've replaced a few lithium bromide absorption chillers in my work place. I skipped around the video, so I'm not sure if I'm understanding his design but I'd be just using water as the refrigerant? Condensing to release heat and evaporating to collect it?

The libr absorber does the same thing but it's sealed. https://www.brighthubengineering.com/hvac/66301-water-lithium-bromide-vapor-absorption-refrigeration-system/

This is old technology that is used in every RV propane powered fridge. We use waste stream to power the ones we have. I replaced two 200 ton units (700kW) and one massive 600 ton (2100 kW) absorber chillers.