I added a misting system earlier this year, simply because my heat pump couldn't keep up, and a hvac friend recommended I add that to help. And it really did....I have to turn mine on by hand though. Much cheaper than a new bigger pump.

I did this and by the end of Summer the coils were all clogged with minerals. This is even after a water softener. It was a terrific job getting the coils cleaned. They're still not completely clean. I urge everyone to consider this possibility.

I'm an engineer and I live in near Phoenix and the tubing and mist heads appear to be standard patio misting system components. I know it's effective because there are commercial air conditioning systems that use similar technology (and are designed to do so). I believe it would work well and would probably pay for itself with electricity savings in one season. However: 1. In some areas (like Phoenix), build-up of hard-water deposits is going to be an issue for both reducing the efficiency of the cooling fins and clogging the misting nozzles. You are naïve if you think that cheap filter is going to remove the hardness from your water. 2. In more humid areas, mold, mildew, and algae are going to be an issue for clogging the condenser fins because they will be wet all the time. 3. Rust and corrosion of the condenser is going to be an issue with it getting wet and drying out several times per day. Edit: Rust of the condenser cabinet is secondary to the issue of corrosion of the condenser tubes/fins. Additionally, some units may fair MUCH worse if they can pull even a small amount of mist through the area where the contactor, capacitor, and other electrical connections are located since that will accelerate corrosion of the electrical connections. On top of the above, I can just look at the components and tell that the quality is really poor. I.e. the plastic tubing and air flapper will be susceptible to UV deterioration and the valve controlled by the flapper will be lucky to last one season. Edit: all it took was a little bit of research and almost everything I expected it true. It has 31% one-star reviews on Amazon with hard water deposits, premature valve failure, and corrosion of the condenser being the main complaints. Oh, and a patio misting kit that comes with everything but the flapper/valve costs less than $20.

Im a business owner in the HVAC industry for 30 years and was a instructor for 10 years. I HIGHLY RECOMMEND DO NO USE THESE. Yes they do lower your condensing temperature which in turn will lower your evaporator temperatures but those coils are not made for this. You will have lime build up on your coils andother deposits. Also the condenser fan has a hole open to the atmosphere on the bottom just in case there was any moisture that gets in the motor. This will cause your motor to fail sooner. By doing this you will be pulling moisture into the motor and bearings. I’ve seen this done many times and the coils will fail. Please don’t do this. If this was good for your equipment all equipment would have evaporative cooling built on them. If you truly want to save money keep coils clean, filters changed, add insulation to your home that has broken down over the years(attic), replace windows or if your system runs all day and half the night it could be to small or just need servicing. PLEASE DONT BUY GADGETS THAY WILL COST YOU IN THE LONG RUN. .8 amps isn’t gunna help your power consumption as much as insulation and windows wood.

Also, it will work best if you're in a "dry heat" area. If it's 90% humidity, I don't think it's going to work that well, because it's going to be harder for the water to evaporate and carry the heat with it.

I've been doing this for over 20 years (in Bakersfield and Las Vegas) and yes, it will save you a ton of money. The idea is to find that sweet spot where it's just enough water flow to make the mist. Remember that it is the evaporation that we are using to cool the incoming air (evaporative process causing the air to cool up to 40 degrees), not soaking the unit's parts.

For those with engineering background...this is simply a change from a closed-looped dry-bulb cooler ( an "air-cooled-heat-exchanger").....to a dry/wet cooling device to take advantage of evaporative cooling effect. The bad part is that the coils (now being wet) will collect more debris or grass or cottonwood, etc...and will be fouled sooner. But yeah...adding a wet-bulb ( vs dry-bulb) evaporative cooling element to the system will improve performance but watch out for coils getting fouled.

I used this exact same mist system on my unit for about 4 years in Central Texas. Before installing this my house could only cool to about 82 when it was 105+ outside during the Texas summer heat. After installing this my house would stay around 78 or 79 so I can deftly say that it does work. The downside is that even with a filter I began getting calcium buildup around the entire unit. Also, the constant moisture caused some minor damage and fading to the siding and paint.

The wire inside the tubing is there to provide rigidity to maintain the shape you bend it into without kinking the tube.

From an HVAC tech- I would like a tube on every side of coil for maximum effectiveness. Also I would install the mister near top portion of coil so cool water can start on top portion and trickle cold water down. Nice design on this. I’ve used my yard sprinkler on very very hot days 😊

I work from home and I go out and spray both my AC units when I take breaks to help cool it down and also keep the cotton weeds from coating the coils. My units are always in the shade and are 16yrs old. I have replaced the capacitors twice since I have owned them and also replaced one of the fan motors before I realized it was a simple $10 capacitor as the issue. I have also replaced the capacitors on my inside blower fans along with one blower fan motor. Doing this yourself can extend the life of your AC units and furnaces. Really cool set up and invention.

Just a note about the piece of wire inside the tubes. It's for forming the tube to make the 90 degree bend over the side. shake it or slide it to the proper position and bend it. Then it will hold the bend without kinking the tubes. Better appearance, and keeps the tube open for the sharp bends.

I did this same modification 20 years ago. I used an electric relay and water solenoid to turn my water on/off. I suggest you also check the discharge temp of the condenser. Nice experiment.

Made one myself our of 1/4 copper tubing with very fine holes drilled into it and used a solenoid valve that was wired into the thermostat wires to turn it on and off. Worked like a charm.

It’s a nice concept but one thing to consider If your unit is in an area where there is a lot of pollen, it will mix with the water and make a “ glue” on your condenser coil.

Well, this reminds me of older commercial refrigerators that used to work in conjunction with your waterline. Was very efficient, if your water is cheap.

I'm glad he mentioned the orientation issue at the end, because I was wondering WHY would you have it spraying toward the house and not on the big open side? I thought maybe there was a reason. In fact, I believe it is only a three sided spray system because they do NOT want you to spray your home side.

Decades ago , some of the pre-coolers for A/C in central Phoenix Az were built from stainless material. They lasted longer. All of these devices made a mess from leakage with calcium on the house roofs since most HVAC were installed on the roofs then. We had a stainless evap cooler on our house. The exterior box lasted, I had to replace the interior squirrel cage parts after 15 years.

I have a manual version of this (a patio mister). Where I live, we frequently (and currently) get temps above 105 to 110 degrees. This makes my unit struggle to keep up and sometimes pop the breakers if the duty cycle (ratio of running/not running) gets high. At these temps, I have rooms in my house that get hot due to direct sunlight. I only run the water when the temps get high to reduce the strain on the system, but the hot rooms also get about 2 degrees cooler when I run the water, so I know it's doing some good. I haven't had the breakers pop either, so I know the amp draw is reduced.

David Zeller is correct I have been in the AC business now for 40 years just retired last week and I have found many of these after about 2 years they completely destroy your condenser coil so for what money you may have thought you saved it will cost you a whole bundle more do not do it I repeat do not do it

I believe that wire on the inside of the tubes is there to make the tubes slightly rigid so you can bend them to the area you want them to be.

I used one of those on my very tired 33 y/o Trane unit to buy me some more time before replacing it. South side of the house. Full sun all day long. Wasn't worried about mineral buildup, corrosion, etc, since she was about through anyway. Actually got me thru 2 more seasons, including a brutal summer that reached 114. She was rough looking after 2 years tho. Cabinet was rusty and the coil fins were not pretty. I could definitely tell a difference in the way the compressor motor sounded with the misters running. Much less labored.

I built something similar with fogger tips on a drip system , but I also built an awning to keep the unit shaded and it was very effective

A buddy of mine added extra line coiled up in a drum. He used lake water to cycle through the drum creating a heat sink to cool the coils. I remember adding a heat transfer device years ago which help heat my hot water by absorbing lines set heat. Worked great!

25 years of working on HVAC in So Florida I would tell people on service calls about spraying a light mist of water on their condenser sometimes when they had a party in the home and the heat load was higher than the unit could effectively handle. There are even other water misting systems on the market for larger systems. I did install a system on a 100 ton condenser unit in a meeting/recreation building that ran off of the head pressure of the coolant.

Just wanted to thank you for your videos. I was able to confirm that my AC capacitor was at fault and I was able to get it repaired the next day once the part arrived from Amazon. Keep up the great work!

Very cool (no pun intended); I’ve been planning to install a swamp cooler on the roof to cool the area under my patio awning. Just put in the water line (1/4 copper tubing). Having watched the video I’ll now split the water line and run water into the a/c condenser too - it’s on the roof also - and give a little love to my air conditioning unit! Thanks for sharing

I had one of these about 1-2 years after they came out. I had seen a show that Bill Nye was on and he was installing one. It sounded good so I purchased one. It did reduce the amount of electricity my unit used and was way more then the cost of the water. Not much water was used. It was like $2 more a month. I am in the south where in the summer we get over 100 many times during the summer. I used the filter and replaced it. After the first summer I did notice a very light build up on the coils. During the second summer it got thicker. I tried a couple professional AC coil cleaners to remove the build up. I did not have much success in removing it. I had a HVAC tech tell me to stop using it and the cleaners because it could cause the wire guard to rust. He said the build up could cause the compressor to fail sooner. Which it did about 5 years later when it was 8 years old. Not for sure if the two was connected but could have been. Over the next few years the wire guard on my unit began to rust. The buildup did have a slight negative effect on the performance of the unit. Something to watch out for.

Note that the water filter, shown in the video, does not remove calcium. It is a water conditioner which slightly changes the chemistry of calcium to reduce scaling, but does not remove it. Also, is slightly (very slightly) make the water acidic, which with the calcium, is not good for longevity of the condenser.

We have done this for years,first one I ever put together was made using Toro lawn sprinkler misting heads attached to a pvc manifold! Its is still used 15 years later,it is on a timer with an asco solenoid valve! This is on a 60 ton drycooler!

In the Air Force when I stayed in Phoenix at Luke AFB only important buildings had AC most people had swamp cooler units that do similar work as this micro mister is doing very nice video well thought out and flawless presentation. I learned something new today.

Since our current heat wave has given us 110° days, and causing our compressor to overheat and shut down, I've been doing this. Works well!

I installed the IRRIGATION -MART Automatic misting kit for 24VAC. It wires into ac control wire and connects to a solenoid valve. It was 60 plus shipping.

Another thing that has worked well for me is that the unit is on the north side of the house under a 7' overhang so it is always in the shade and out of the rain. My original heat pump lasted 33 years in FL!

Thanks,I'm using your Help on Ideas to Reduce my Bill,along with Tips for Better,AC Cooling,Efficiency!I Shop Vacked the Drain Line,Whoa!Its workin like it was just Installed,with the Cool and Save Mister!An Attic Fan Temp,Time control!My AC went from 60 degrees to 51 degrees,and Runs Less!Thanks!Again!

Back in the early 80’s there was a product called ‘’Mist Miser’’ to perform the same function. It used a solenoid triggered by temp to apply the mist. I used a cheap mister designed for wrapping around a lounge chair and connected it to my sprinkler well water. Seemed to work somewhat but my unit was in constant shade. Never tried to quantify the change.

I don't think your register temperature is all that relevant without tracking the temperature at the return, but the reduced amp draw is undeniable. I wonder about the long term affect on the condenser even with soft water. I think filtration needs to be high priority with this type of kit, and that inline business has me in doubt.

Shade makes a big difference also! Need to maintain space around system for airflow though. Also when the temps drop down to probably 80 yo 85 outside you should cut the water off because you need to maintain a certain head pressure in the system to keep the evap from freezing up. I made one with mister nozzles, 24 volt sprinkler valve and pvc pipe on an old system and it worked great.

I spray my A/C twice a day, morning and mid afternoon it works great! Thank you garden hose sprayer!!

It’s a neat concept and yes it kinda works. If you have a newer heat pump system or a system that uses a TXV it’s not going to work well and actually hinder cooling. Using the misting system You are charging the charge pressure/liquid line and you are changing the way the TXV acts. If your going to run one of these systems, you need to charge/add Freon to the system to the appropriate levels. If you have a heat pump system and charged/added Freon while using the misting system you will need to remove Freon during the winter months. since a heat pump system runs all year your not using the misting system during fall and winter So now the problem will be the system is over charged and not function correctly while using heat. IMO these misting systems are good for straight cool (cooling only)systems with the old school piston/cap metering device. I’m no expert but have been doing HVAC work for 16years and now own my own HVAC company. I live in south Texas, I’ve seen all kinds of crazy misting systems setups to keep cool. Best advice for any hvac system especially during the summer is to keep the outdoor system out of direct sunlight.

Makes sense because a hot condenser increases head pressure and therefore amp draw on the compressor. So cooling off the condenser coil would reduce the amp draw.

I had 255/75R16 on my 84 Suburban and LOVED them!! I sure wish BFG had a KO2 in that size for the tow vehicle.

I did this once and it was awhile ago. Pretty sure i just bought a 24v relay solenoid that kicked the water on when the ac kicked on and turned off when unit kicked off. I used a waterline kit for a fridge ice maker for water supply and hooked up a mister kit to it. I only ran it for one season in a rental i lived in. It worked great. I didnt comapare any energy numbers to see if i saved anything nor did i run it long enough to see long term negative effects on components.

Thanks for trying it out and doing the video. I had an idea like this 20 years ago, but was afraid of corrosion or build-up on the coils. If I get a 0.9A reduction in power usage from the solution you showed, at 10 cents per kWh, it would take 10 years for me to recoup my money from this (assuming water filters were free). It is a good idea, but costs too much to be worth it. I've found the thing that has made the biggest difference for me, by far, is adding more insulation to the attic.

Loved these devices when I was a HVAC tec! Job security the coils will totally crumble in time and require unit replacement!

I did mine the homemade route. I routed irrigation hose (not garden hose) to the AC from a pipe in the garage, so super easy, and no garden hose issues (they burst). I also put in a shutoff valve. Instead of a flap on the AC I did it another way. I plumed in a sprinkler valve switched on by the same 28V as the AC so it turns on the water using the same signal. I also put in a toggle switch for that as well. This way I can shut it all off for winter by turning off a valve and a switch. And should the plastic pipe burst in a cold snap the water is off from inside the garage so no problems. I think my total cost was around $75. But I also had to buy some fittings etc. so more than that.

I built one almost identical to yours about 15 years ago lol. Nice work.

I've always wondered about putting misters on the A/C unit, but was concerned about the hard water building up scale on the coils

I used to put the tubing from the condensate pump on split systems and let the water pump out on the condenser coil outside to help lower head pressure and take a little stress off of the condensing unit. Never measured and checked the difference it made but you know it had to help. Especially as cold as the water was coming from the condensate pump !!!

I have been using a $20 misting kit I found on amazone four about 4 year. Like others have stated, don't smoke the system just lightly mist. You can real notice a difference in 90 + heat!

Suggest putting a shade over the heat pump so that there is no direct sun light. Not immediately and in contact with the unit but with sufficient space above the unit to allow for complete airflow. And you only need the properly angled shade to cover the unit when the sun hits it.

I bought one last year to test out on one of my A/C units. (I have 3). I was excited when it came in the mail. The kit was about $100. It took me about 30 minutes to install. It was easy. It worked as designed. However, after a week or so of use, I started to notice a white haze was developing on the condenser coil fins. Despite installing the hard water filter that came with the kit, it wasn't enough to remove the calcium from the hard water. I had to stop using it out of fear that the fins would be saturated with calcium, and therefore reduce both the efficiency and lifespan of the condenser. I was very disappointed.

You make GREAT videos. Thank you.

I made one of these for my AC in Phoenix with a garden mister hose. It did help.

Pop used a regular plant waterer tube and a Patio Umbrella over the unit. And he hosed it out every summer, it lasted 22 years, total.

I was actually telling my wife just today I wish I could make a setup to mist water on our unit, which is in direct sun from about 10 to 3 every day lol. My opinion, but I think if the back sprayer was relocated to the front you would have a greater result since the rear is pretty much shaded and the front is in full sun.

I used to live right by the ocean and the salt in the air would corrode the fins after a few years. I think having one of these would actually help since it would be constantly washing off the salt. The only issue might be if you live in an area with hard water. I had to put in a whole home water softener. I put it outside prior to everything else; even the water hose.

The house in which I grew up in Tucson Arizona had a Rheem unit that had a drip system built in that would constantly flow water over the condenser. It worked like a Swamp cooler where there was a float that would feed water into the bottom tray and a separate pump for recirculating the water. It was incredibly efficient, but also incredibly wasteful, especially in the desert. My recollection is that this system was installed around 1964 and I can't find anything online about it. What made it be able to withstand this was the condenser was stainless steel, so you didn't have to worry about untreated tap/well water corroding out the condenser.

I had the compressor fan fail one weekend and didn't have time to fix it for a few days so I just hung a sprinkler on top the compressor where the fan was mounted and turned the water on just enough to keep the coils wet. Worked great for 3 or 4 days until I could get another motor.

A mister will help, BUT you have to do a lot more maintenance to keep the coils clean. I have done this professionally in extreme conditions. But there was a lot of cleaning of coils.

18% savings. Depending on sun at time it appears the savings could be greater when sun is shining directly on unit. Good video. Not sure about hardness of water and what effect it would have on coils over time unless they were cleaned regularly. Thanks.

I did something like this in Las Vegas, 20+ years ago on a roof unit. Mine was like a swamp-cooler before the condenser. So the hot dry air was pulled through the swamp cooler to pre-cool the air as the condenser sucked it in. Worked great and lowered the head pressure on the compressor. Then after 2-3 months the lime built up on the coils and destroyed the unit by blocking all air flow. If you attempt this I would suggest that you keep the swamp-cooler assemble at least a foot from the coils and reduce the water flow.

I am a business owner and the HVAC industry for 30 years and also served that as an instructor for 10 I highly recommend these

Well done. I may try this on my Carrier heat pump. It is located south facing in SoCal so it is always baking in the sun. It would've been nice to see the ambient air temperature to help draw a correlation on when the amps go down and by how much depending on the outdoor air temp.

8 Months later I can tell you this contraption works! I bought this rig right after watching this video. I live in the Ft Lauderdale area, on ocean access water. I installed this and noticed a difference right away. I did not do amp ratings but I did do temp ratings and I found the air coming out of the vents in the house were a solid 5 degrees cooler and the electric bill went down by a few bucks.

Cool idea, since it is the outdoor unit, in the rain, snow, etc. a little water is nothing to worry about. The Amp draw reduction is amazing. The people talking about only one degree cooler at register, that is not the objective people, it's a bonus when is that low already! I do have concerns on the air flow arm, looks a bit flimsy and winds in my area will rip that off over time. I think a solenoid controlled fan relay, or amp draw sensor would be more solid. I've used this idea, temporarily in emergencies when delay getting new/proper condensing fan, and use garden hose spray. That uses way too much water for perm solution of course.

I lived in Yuma, Arizona years ago. My AC was on the roof. The air is very dry and the summers are very hot. They put honeycombed paper material around the AC and drip water down through the paper. It cools the air down going into the coils. The honeycombed material needs to be changed periodically because of calcium buildup on the paper. It works very well and because it doesn't drip water on the coils nothing collects on them. I think it's got to be dry to cool the water so it will evaporate and cool down.

I've done this while charging my old Toyota pickup. I use the garden hose on mist and hang it in front of the condenser while I'm charging and testing. You should hook up a set of gauges and show people what the high pressure side does when you spray cold water on the condenser. It drops dramatically. You've basically removed a big portion of the heat load from the compressor and it shows in the lower amperage draw. Less amps = less work, and vice versa. But in order to test a change of capacity you should have used a differential of the entering air temperature and the leaving air temperature. Simply measuring the leaving air temperature does not show whether you had a colder entering temperature at the time of testing. So if you measured 78° EAT (return) and 55° LAT (supply) you have a delta T of 23°. If you measured the 2nd time and got 70° EAT and 50° LAT you have a delta T of 20°. Now that's just an example. You probably did gain some capacity. But how much is anyone's guess without a longer formula. The reduced amp draw is what you really need to be pointing out to people. From 4.6 to 3.3 is a Whopping 28% reduction! Assuming your unit is 208-230 volts that's a 300 watt reduction in energy cost over how many years?! That's what a lot of people fail to take into consideration. Wattage used over time. The more you can reduce wattage and the longer it goes the more money you save. "Every penny counts."

I'd be interested to see how much dirt collects over time. Moist coils and dusty air streams make mud. True swamp cooling devices usually have a flow over the coils to keep them clean and you simply purge the sump every once in a while.

This is perfect timing! My condensor fan has been overheating and tripping the circuit breaker since temps started hitting 95 degrees a couple of weeks ago (the motor has thermal protection of some kind, but it doesn't seem to be working, hence tripping the circuit breaker). After I replace the motor, I am going to get one of these!

This is my 2nd summer in oklahoma city using this, working fine, small amount of lime build up. Will spray with vinegar solution this fall. Try it if you have high temps and soft water.

There is only ONE problem with this... the mineral build up on the coil, but it does work. A number of years ago I built a pvc pipe system with misting nozzles. Eight altogether. It was attached to a 24v sprinkler valve and the water feed was 2 feet from the hose bib. Electrically the valve was connected to the contactor. Condenser (5 tons) comes on... valve opens and it misted the condenser. It dropped the amps by 3-4. After 5 plus years no cleaner, acid or otherwise would remove the deposits. If you can STOP the mineral deposits I highly recommend a mister in extreme heat. Side note... HVAC contractor friend of mine had a package unit on the top of a flat tar roof building. He created a mister because in Texas it gets HOT in the summer. It worked.

I thought about misting the condenser coil years ago. Never tried it. Then an exec from Trane explained to me the best way to lower AC electric bill is set the T-stat 2 degrees higher. He stated the unit works very hard lowering the temp that last 2 degrees. So I tried this, Sure enough he was right and it made a big difference. It also puts less time on the compressor and blower motor.

I need that. I have two units and they run hard and are in the sun all day. wish i saw this before the summer opposed to the end, but everything helps. Thanks for the video.

50 years ago my Dad set up some kind of contraption like this in Abilene Texas and it helped cool our house faster.

They should make it use water from the evap drain. It's naturally distilled. I made my own version of this decades ago. I also shaded the unit, and had plants growing near it.

Would have to weigh the energy cost saved versus the cost of the water, filters, and risk of damage to the unit but I like the idea.

an airflow director above the unit can also knock about 8% off your bill and extend the equipment's lifespan as well... just a twice-bent piece of metal that shields the top when the fan is off and is lifted out of the way when its on but still deflects the airflow away from the wall and eaves above. The main trick here is not to directly spray onto the coils but to spray onto a surface around the air conditioner's outside unit - the benefit is gained without a direct application!

this is incredible, my AC unit is directly in the sun most of the day, the west side of the house so this should work really good for my house

What would be really great if the water that is condensing on the evap coil could be used to cool the condenser coil. The water would be without calcium and is otherwise just wasted.

As someone else said in the comments I think I would attempt to shade my condenser without restricting airflow like a sail shade or something.

I've had great results with misters on car radiators. Really helps to drop coolant temps. Im not surprised that it works well on outdoor AC units. Great video!!

I've been using one of these since 2017, I live about an hour away from Vegas. It works really well and cuts my power usage to about 1/3rd of what it was when the temps get up to the >110F range. However, at the end of each year I have to spend a saturday cleaning the hard water deposits off of all the fins. I would not recommend it unless you are prepared to take your condenser apart and manually clean it yourself every year.

Cool design! I would think having side spray nozzles would be more efficient.

We had a customer with a big chiller, that had a beat down condensor coil, due to age and hail damage. Rather than repairing the unit, they set up sprinklers on the coils, and ran it for years that way.

I did some of this with my hoes and a set of gauges to see the pressure variance and it was significant so I did around the unit with the patio sprayer coolant lines and didn't have much of a significant change but I know the condenser unit did enjoy and benefit from the reduced high side pressure level being reduced significantly from 240 to 160.

Good job! If u follow the high side line you can see where it enters into the condenser coil and thats where the hottest refrigerant will be found. Generally its at the top left of the service panel. I wish they would have made a mount that could utilize 2 of the condenser fan bolts to make sure the switch never comes off. Those fan motors can get quite hot especially if they are going bad.. For fun drench it with a hose with the clamp meter hooked up. The amps will really drop

This famously reduces the lifespan of your AC system. HVAC manufactures aren't fools, there is no one trick pony here.

The better design is not to spray mist onto the coil but to let water dripping down a disposable filter wrap outside the coils. Evaporation of water will lower the temperature of air that flows through the coils/fins. This will prevent corrosion as water never touch the fins.

As an over-the-road driver I sometimes pulled temperature controlled trailers, reefer, and in the summer it can be hard to get the temperature down for the load carried. I had one load in particular that had to be shipped at -10°F or -23°C and at the time the lowest I could get it was just above 0°F but they loaded it anyway. Due to my hours situation I didn't have time to do what I really needed to do and that was spray the reefer unit down with water. The reefer unit is that thing on the nose of the trailer that heats and cools the inside. I finally managed to get the temperature down to where it was needed the next day by running through a thunder storm. With the sprayers spraying away from the AC unit surprised me. I was expecting to see them pointed inwards instead of outward...

I've been using spray misters on my AC unit for decades. It helps a lot.

Yup, this works. I did this while in Iraq in 2003-04, it gets 140 in downtown Baghdad so A/C was critical for us and if it wasn’t working right we did things like this to keep it cool until we got it fixed properly. And make sure you buy spare capacitors for your unit.

What about the water causing lime build up on the coils ?

I made my own using a sprinkler valve, misting nozzles from Home Depot, and a time delay relay switch.

I realize that outdoor units are designed to be all-weather. But are the designed to withstand constant water-immersion? The coils are, nowadays, aluminum and corrode very, very slowly. But the housing is sheet metal. Housings corrode on their own over time. I wonder if this water unit will cause undo corrosion on ferrous parts....

Not sure why you'd expect the noise to be any different, or be concerned with noise for that matter, it's outside. Main thing is that it works and maintains the thermo setting.

My grandma just had me do this for her this past weekend. I just got a $20 Mister kit at Lowe's and pointed all 6 of them inside the unit.

I work in a little shop in the late sixties early seventies we had a small commercial unit now that's in Arizona very dry climate it worked great

Now that it's installed it'd be nice to see a video of ac running steady state with amp probe and register Temps shown then turn on water and observe change in amp draw and temp

most window AC units already use this sort of system... they tell you not to drill or drain the metal bottom, it collects condensation water and the fan splashes in it to help cool the outside coil.