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Dry Water Cooled Air Conditioner

Water spray is inside closed cooling chamber
  [vote for,

Instead of spraying the water into the open air, bringing up humidity and causing it to be used only outside, this unit works with water sprayed inside a closed chamber, with air flowing in from a radiator.

An external fan behind the cooled radiator sends open room air throughout the room. The closed air with the water that was absorbed is either piped out of the room, to be cooled in the evening and returned in the daytime.

Another option is to recycle the humid air through a low pressure chamber achieved by sucking in air when sending the water to the spray nozzle.

pashute, May 01 2014

like this? http://www2.buildin...hout-added-humidity
coolerado punderfull [popbottle, May 31 2014]

CSIRO research Indirect Evaporative Cooling !! http://solar.org.au...rs/08papers/229.pdf
[pashute, Jun 23 2016]

CSIRO video - "super cool air conditioning" https://www.youtube...watch?v=cz-kquRmvqk
hot water, cooling and heating... [pashute, Jun 23 2016]


       What is the aim here? to cool the air? In which case would a refrigeration circuit not make more sense? If you air circuit is sealed then once the air in the circuit becomes saturated how does spraying more water help? Unless you dry the air at the other side of the circuit, which usually requires a refrigeration system to condense the moisture back out of the air, and then in which case why not just pass the room air over the refrigeration coils in the first place?
pocmloc, May 01 2014

       I think I'm probably getting this backward, but if you're thinking of evaporative cooling that keeps the humidity out of the room to be cooled, then it might help to actively pump air from your evaporation unit, keeping pressure at some low level that might drive equilibrium in the direction of more rapid evaporation?   

       If you were on the coast of Mozambique, you certainly wouldn't want any more humidity in the room than that already provided by the hot sea, so this would perhaps be a viable way of doing evaporative cooling in such a location. Seal up the room, evaporatively cool an attached ventilated chamber, and if you can directly drive that with the wind, you might have low-tech cooling suitable for eg. the islands near the Tanzanian border. (Using salt water, even.)
skoomphemph, May 01 2014

       Yup, evaporative coolers are widely used, & only effective in dry-air heat (southwest USA esp.) Those are "open circuit".   

       If you close the circuit, you have to deal with the condensation, & then you're essentially doing what fridges & other closed-loop circuits already widely do today. When closed & isolated, a better fluid than air is often used as well.   

       So, what is new in this idea? It sounds like how most home A/C systems already work, but with less efficient fluid?
sophocles, May 01 2014

       Air conditioners are expensive, and gas runs out of them occasionally. We find out years later how dangerous these gases are, and what the effect of their production was.   

       Water coolers are cheap, abundant, but work only in dry arid areas, so they are not suitable for Mozambique, Islands off the Tanzanian border or for Tel Aviv. They are usually simple fans that spray water into the fanned air, or ice chambers that have the air pass through the ice, or sprayed ice-water.   

       The idea here is simple: move the energy laden damp air, which has absorbed the room's heat, out of the room. This should cost much less, take much less energy, and have a much lower initial cost than an air conditioner.   

       This is achieved by spraying the water into a closed chamber and taking the heat from the room's air through a radiator. Then leading the damp air out of the room and getting rid of it externally.   

       The only problem with this method is that it consumes a lot of water. Not good if you don't have a source of waste-water at your hands. Water is usually a scarce resource, and could be expensive too.   

       So in comes option two: My claim is that for extracting much of the water from air, you need much less energy (and cooling) than that used by conventional cooling-gas AC systems, for cooling air to typical AC temperatures.   

       One proposed way I had for achieving that without adding any parts was by creating a low pressure chamber, that has air sucked out of it during the spraying process. Once the chamber reaches a certain low pressure, the damp air is sent in, condensing (with the help of a condensing net of course) and the water is sent (through gravity) back into the water storage.
pashute, May 07 2014

       This is probably a stoopid ideal, but how about a tall black pipe running into the house/flat, the pipe would get heated by the sun, the air would rise, so promoting a breeze in the house? Better than nothing and zero usage of water.
not_morrison_rm, May 07 2014

       By closing the loop here, you do make it identical to a traditional refrigeration system, you are just choosing to do it with the least efficient refrigerant in common use.   

       //My claim is that for extracting much of the water from air, you need much less energy (and cooling) than that used by conventional cooling- gas AC systems// This is simply not the case. The gasses are used specifically because they are very efficient.   

       If you're worried about the gasses from an AC unit, switch over to ammonia/water, or any of the other combinations that work. It's less efficient than the R-400 series refrigerants, but it's still far more efficient than the water/air combination you suggest here. All of the above are already in common use.
MechE, May 07 2014

       Maybe I need a diagram. Or more verbosity to lay out each stage?   

       If you blow your room air through a cooled radiator you have a dehumidifier. The cool air loses moisture to the radiator coils and drips into a catch basin. Cooler and dehumidified air moves thru the room.
bungston, May 07 2014

       How about this scheme for pressure: on the roof is a large pressure chamber. Maybe a repurposed propane tank with huge curling art deco metal radiators affixed to all surfaces. In Israel it is solar powered.   

       1. It has gears and the solar motor slowly depressurizes the tank over some time, to about 1/2 atmosphere. Water leaving the depressurized air enters a catchment tank. Is a propane tank good for low pressure or only high?   

       2. At maximum cycle it reverses and now the air is pressurized to 2 atmospheres.   

       3. It may be necessary to hold at max pressure for a while - the air will get hotter as it is pressurized and there needs to be time to lose this heat through aformentioned fins and wings.   

       4. Now when this dry air is vented into the room, it is going from high pressure to low and so be cooler as it comes in. It will also have been dehumidied and so one will bask under a waterfall of dry cool air, courtesy of old sol.   

       5. Cycle repeats.
bungston, May 07 2014

       I wonder if dehydrating the air with a drying agent would be faster under pressure. For example   

       1: Pressurize outside humid hot air to several atmospheres.   

       2: Drying agent (eg calcium chloride or even sodium chloride) more effectively removes water from a given mass of air when there is less volume.   

       3: While drying agent works, heat is also dispersed from pressurized air which is now relatively hotter than the environment.   

       4: On depressurization, water captured by drying agent does not reequilibrate into gas. Depressurized air is now relatively cooler than the environment. Into the house!   

       The nice thing about this is that drying agents are cheap, nontoxic, pressure insensitive and can be regenerated.
bungston, May 07 2014

       Swamp coolers are "free" in the sense that, as long as you have enough room in the air for more humidty and there's a wind to remove the extra-humidifed air, you have a cooling system.   

       I don't see where this system removes the extra-humidified air.
FlyingToaster, May 07 2014

       Isn't this just a standard air conditioning system using water instead of freon that doesn't recycle it for re-use in the system? That's pretty much what a swamp cooler that isolates the evaporated water from the conditioned envelope would be. If that's it it's not a bad idea.   

       If that's not it I'm confused.
doctorremulac3, May 07 2014

       That's it.
pashute, May 26 2014

       A set of heat pipes between the wet and the dry flows might get the heat transfer up to something acceptable. Worth a shot.
popbottle, May 31 2014

       I just saw this (see links) research from the 1970s and recent development. Looks legit and sounds fantastic!!   

       DEC is Direct Evaporative Cooling where the water is evaporated directly into cooled air supply.   

       Indirect Evaporative Cooling is what I proposed in this idea two years ago.   

       Quote: From the late 1960’s to the mid 1970’s Donald R. Pescod, a CSIRO researcher, experimented with Indirect Evaporative Cooling. He perceived that an IEC system had all the benefits of DEC cooling and did not have the drawback of increasing supply-air moisture content. Pescod’s innovation was to use a plastic plate heat exchanger in place of metallic heat exchangers, as were used in the past...   

       Also putting up the youtube showing their unit. Minute 1:08 is where they begin the actual introduction. The desiccant wheel is shown about 2:01 and the IEC at 2:30 claimed to create "cooled dry air" which goes into the home.
pashute, Jun 23 2016


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