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Author Topic: Mistbox: Energy-saving device proven to cut AC bills by 30%  (Read 986 times)

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Online EEVblog

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When you see "energy saving" and Crowd funding in the same sentence, your spidey sense instantly goes  :bullshit:

I have not looked into this, and I'm guessing it's possible, but as always with these things the claims will be almost certainly under ideal circumstances with your tounge at the right angle, and with the wind in the right direction.

https://www.kickstarter.com/projects/19381/mistbox-energy-saving-device-proven-to-cut-ac-bill

They claim to have had Intertek test it.
But then again, UL "tested" the Batteriser, so...
 

Offline BradC

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #1 on: June 16, 2017, 07:03:40 PM »
Yep, that'll work just fine.
It works in two ways.
A) it provides "some" evaporative cooling to the air entering the condenser.
B) the remaining water droplets land on the condenser and provide direct cooling as they evaporate.

A couple of gotchas. If you live in an area with a high mineral content the nozzles will foul pretty quickly. If they don't, then its because the water is not properly evaporating and will then cause mineral fouling on your condenser directly. My experience with this sort of technology is it requires more frequent condenser cleaning *and* reduces ultimate condenser life as it promotes some corrosion on the fins.

By lowering the condensation temperature you lower the pressure the refrigerant has to be pumped up to. If the evaporating temperature remains the same and the condensing temperature drops then the compressor is not working as hard and will draw less power. One other gotcha on non-inverter single-phase units is as you reduce the compressor workload your power factor goes to shit.

I have a unit at home where I replaced the air-cooled condenser (SCT 70C) with a bore water cooled heat exchanger (SCT 22C). Great, it dropped the compressor power significantly, but it now has a power factor in the order of 0.3 to boot.

I have no doubt this unit works, but 30% is questionable and is the extra maintenance (nozzle/condenser cleaning) and potential reduced unit life worth the tradeoff?

 

Online mikeselectricstuff

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #2 on: June 16, 2017, 07:17:07 PM »
Subscription service  :-DD
Youtube channel:Taking wierd stuff apart. Very apart.
Mike's Electric Stuff: High voltage, vintage electronics etc.
Day Job: Mostly LEDs
 

Offline abraxa

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #3 on: June 16, 2017, 07:47:13 PM »
Subscription service  :-DD

Yeah, and what happens if the cell connection stops or they shut down the servers? Does the mistbox suddenly stop working, too, even though there's no objective reason for doing so?

It's also funny to look around their FAQ. It doesn't mention corrosion inside the unit (I doubt the fan motor likes moisture) and it even says that they "recommend that you take Mistbox down if a hard freeze is expected". Uh yeah, how about adding a valve to auto-drain the unit when temperatures drop too low to operate? I guess that would've been either too expensive for them or they simply expect this unit to be operated mainly in tropical/desert climate.

One last thought: water is a scarce resource in certain regions of the world and it's not going to get better. Take Cali as an example. Does it make sense there to spend water on cooling instead of sustaining humans and nature? I doubt it. I'd argue that it would be better to use solar panels to make use of the sun. But then again, you can't easily turn that into an IoT subscription model...
 

Online blueskull

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #4 on: June 16, 2017, 07:53:31 PM »
I think it is a viable design, and I put good hope on it.
However, the subscription model? Good bye.
In less than 100 years, implantable defib units will also be subscription based. Forgot to pay this month? Go to hell!
SIGSEGV is inevitable if you try to talk more than you know.
 

Offline ar__systems

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #5 on: June 16, 2017, 08:42:05 PM »
They have an option of "own mistbox" for crazy $400, but even that required cell service. That I can't even begin to comprehend...

 

Offline Khendrask

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #6 on: June 17, 2017, 01:13:10 AM »
Yes, a mister for the condenser can definitely help.
That being said... "Subscription" ? Bullh***.

And that "Mister" doesn't provide enough output to be useful.

Go to amazon: https://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=misting+system&rh=i%3Aaps%2Ck%3Amisting+system

I actually have this nozzle planted in front of my condenser:
https://www.amazon.com/Kangnice-Agricultural-Misting-Sprinkler-Irrigation/dp/B010GZODKQ/ref=sr_1_34?ie=UTF8&qid=1497625796&sr=8-34&keywords=misting+system

It is driven by a 24 VAC irrigation valve from the cooling demand line from my thermostat.
https://www.amazon.com/Orbit-57100-4-Inch-Threaded-Sprinkler/dp/B00004S1V2/ref=sr_1_2?ie=UTF8&qid=1497625828&sr=8-2&keywords=orbit+water+valve

Works great, and reduces the condenser load significantly.
 

Offline edpalmer42

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #7 on: June 17, 2017, 01:34:18 AM »
AFAIK, every small window air conditioner uses a variation of this idea.  When the fan spins, one or more 'fingers' on the fan dips into the tray that holds the water that drips off the evaporator coil.  The water is splashed/sprayed onto the condensor coil to help cool it.  I've seen warnings in the instruction manual that this water is important and don't go drilling holes in the bottom to drain it out.

I've also seen customer reviews where people complain about water in the bottom of the unit that they had to drain by drilling holes in the bottom.   :palm:

Ed
 

Offline SeanB

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #8 on: June 17, 2017, 02:58:51 AM »
So, basically the more expensive and IOT connected Samsung window wall unit, with the same sub 2 year condenser coil life as well around here. I have to drill the holes, as otherwise the coil rots from the inside out in under 2 years, and in any case the base falls apart after 5 years. In a split unit this might work, but the coils will still rot away very fast, unless you make them from something a lot more corrosion resistant than the thin foil and tubing they currently are made from.
 

Offline dmills

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #9 on: June 17, 2017, 09:56:13 AM »
Adiabatic cooling of condenser feed air is pretty standard fare in larger plant where conditions favour it (Low RH, and high ambient). You very much DO want the water to evaporate before it hits the condenser or the coils will rot as has been noticed, and you do NOT want to run such things from standing water pools.

The good stuff in industrial systems draws the air thru a wet mineral wool sheet that is kept damp by a spray thus avoiding liquid hitting the condenser coils.

Subscription service? Fine, if the subs cover them sending a guy out to clean and maintain the thing once a month! Maintanance contracts are standard fair, and a GSM modem is not that uncommon on plant....

Regards, Dan.
 

Online EEVblog

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #10 on: June 17, 2017, 10:01:53 AM »
Subscription service  :-DD

Yeah, because it worked so well for Juicero  ;D
 

Online EEVblog

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #11 on: June 17, 2017, 10:03:06 AM »
They have an option of "own mistbox" for crazy $400, but even that required cell service. That I can't even begin to comprehend...

That is double  :palm:  :palm: worthy
 

Offline MikeJuszkie

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #12 on: June 17, 2017, 02:34:54 PM »
assuming that the mist does work.. why would you need a learning algorithm... just mist it when then AC is running.
 

Offline ar__systems

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #13 on: June 17, 2017, 10:01:12 PM »
assuming that the mist does work.. why would you need a learning algorithm... just mist it when then AC is running.
Because if it is not Artificial Intelligence, it is a stone age. :)
 

Online komet

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #14 on: June 17, 2017, 10:08:06 PM »
"Mist" is German for "shit", so very apt indeed.
 
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Offline noidea

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #15 on: June 18, 2017, 12:01:51 AM »
It's nothing new as the other have said.
I started my apprenticeship at a hospital in 1986 and there was an air cooled water chiller plant serving one building at the site that struggled on high load days, no prizes for guessing who's job it was to stand there with the hose for a few hours in the middle of the day misting the condenser coils so the system didn't trip out on high pressure....

The tradie and I got smart and had the plumbers department plumb a water supply near the unit and we installed irrigation water sprays that we controlled with a pressure switch and solenoid valve on the water line so it was automated. It looked a little more agricultural than the one they are spruiking tho.

As with everything there's always a downside, our water supply is pretty poor and it did start to accelerate corrosion of the condenser coils after a couple of seasons.
 

Offline nixfu

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Re: Mistbox: Energy-saving device proven to cut AC bills by 30%
« Reply #16 on: June 20, 2017, 04:59:05 AM »
This has existed forever, minus the IOT wank words.

http://www.coolnsave.com/index.php/How-Does-it-Work.html
 


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