# Window AC Air Conditioner to Water Chiller Conversion Log



## billbartuska




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## ryan55000

I'm really considering doing a build like this myself. Cant wait to see some temps.


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## [ShowMe!]

*I FAILED!*

Part two!

I insulated the pipes, and started to apply foam, in preparation for the water box, and then failed hard by cutting right thru a copper pipe with a knife, it was a total careless move, and I was not thinking about what I was doing.

Anyway, its so sad, I will have to order a new unit.

So Sad Right Now!

I Will Not Give Up!


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## XanderTheGoober

Man after your bong build log this aught to be good. Got my sub!


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## Epitope

Cant you just braze over the hole in the copper pipe? A simple propane torch and some braze at a hardware store should do the trick. Should only take a minute to fix. All those pipes are brazed together at their joints anyways. No reason why you can't patch a hole with it.

I also fail to understand why you need to remove the fins from the cooling side. Wont leaving the fins on just increase heat transfer from the water to the coils?


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## [ShowMe!]

Quote:


> Originally Posted by *Epitope*
> 
> Cant you just braze over the hole in the copper pipe? A simple propane torch and some braze at a hardware store should do the trick. Should only take a minute to fix. All those pipes are brazed together at their joints anyways. No reason why you can't patch a hole with it.
> 
> I also fail to understand why you need to remove the fins from the cooling side. Wont leaving the fins on just increase heat transfer from the water to the coils?


I can do the brazing part, but I don't have any equipment and my refrigeration knowledge is only what I watched from YouTube refrigeration 101 videos.

Can any one chime in and see if it would be easier to refill or buy a new unit?

Wet copper and aluminum = galvanic corrosion, that why I removed the alum fins.


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## billbartuska

Solder: SilFlos
Not a propane torch, not hot enough. A Turbo Torch.

There are very high pressures involved, Don't mess around.

Also, you can't refill the gas, It has to be done by a Certified HVAC technitian. You can't even buy the gas.

I'l bet if to took the unit to a local, small HVAC shop, they'd do it. but the gas will be expensive $100?


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## marc0053

Very nice








Sub'd


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## NoL

Hey there. Good start till the oops. Where are you located? Might be easier to find a local HVAC guy to refill it.

Normally on an AC conversion, I drain it and cut off the evaporator coil. Replacing it with a plate heat exchanger is cheaper than having to build a reservoir and it works for better. Plus it's easier to insulate and it let's you fit a pump in the system.


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## NoL

Also galvanic corrosion isn't much of a concern since you'll need to run antifreeze most likely. We used to take the fins off because the small space between required a lot of pressure from the pump to feed through, and the temperature of the evaporator could freeze it up to one thick popsicle.


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## coachmark2

Awesome project! I think that since cutting that copper pipe, the only thing that can be said is:

http://www.nooooooooooooooo.com/



But seriously....



Keep going!


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## [ShowMe!]

*I have donated the broken AC unite to a scrapper on Craigslist.

I have also ordered a new one, and it is on its way here.

This saga will continue.

If any one has good suggestion on what Antifreeze or Glycol / Distilled Water to use, in what dilution, and where to buy, I would like to know!

I can get distilled water at the grocery store but glycol or antifreeze comes in so many different varieties.

Any proven non toxic ones that have been use for cooling before?

My reservoir is a 150 quart / 37.5 gallon cooler.

*


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## marc0053

Quote:


> Originally Posted by *[ShowMe!]*
> 
> *I have donated the broken AC unite to a scrapper on Craigslist.
> 
> I have also ordered a new one, and it is on its way here.
> 
> This saga will continue.
> 
> If any one has good suggestion on what Antifreeze or Glycol / Distilled Water to use, in what dilution, and where to buy, I would like to know!
> 
> I can get distilled water at the grocery store but glycol or antifreeze comes in so many different varieties.
> 
> Any proven non toxic ones that have been use for cooling before?
> 
> My reservoir is a 150 quart / 37.5 gallon cooler.
> 
> *


Drewmeister recommends windshield washer fluid. It is less thick with sub-zero temps than Prestone and other antifreeze/distilled water solutions. He mentioned that even though it is flammable it is less flammable than other alcohol solutions.

http://forums.extremeoverclocking.com/showthread.php?p=1271686&highlight=windshield#post1271686

BTW I just bought an 12.6K btu A/C with R22 gas to do the same exact thing you are doing








I'm happy to see others do this as I've never done this before and have loads of questions.


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## [ShowMe!]

Quote:


> Originally Posted by *marc0053*
> 
> Drewmeister recommends windshield washer fluid. It is less thick with sub-zero temps than Prestone and other antifreeze/distilled water solutions. He mentioned that even though it is flammable it is less flammable than other alcohol solutions.
> 
> http://forums.extremeoverclocking.com/showthread.php?p=1271686&highlight=windshield#post1271686
> 
> BTW I just bought an 12.6K btu A/C with R22 gas to do the same exact thing you are doing
> 
> 
> 
> 
> 
> 
> 
> 
> I'm happy to see others do this as I've never done this before and have loads of questions.


Can you also do a build thread, so we can both learn from each other, if time permits of course, but would love to see your build thread too.

I will have to wait for the new unit to ship to me.


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## Puck

Sucks about the mishap!

I have a window unit in the porch waiting for the same thing(Small 5k BTU I think), but in my crazy mind I will be running the phase chiller into a TEC block...but that is a log time from now(year or two?) and after I move and build my PC Desk







.


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## NoL

That really wasn't a dead system







would gladly have bought it off you for the compressor condenser combo.


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## [ShowMe!]

Quote:


> Originally Posted by *NoL*
> 
> That really wasn't a dead system
> 
> 
> 
> 
> 
> 
> 
> would gladly have bought it off you for the compressor condenser combo.


Hi NOL

I think even if I gave it to you for free, the shipping cost would have been about 75% of the cost of a new unit with free shipping from Walmart

I can not ship things for free like walmart, and this thing is very heavy and has a large box. UPS would charge an arm and leg for shipping.

Check out this list of AC from walmart, everything has free shipping.

http://www.walmart.com/search/?query=air%20conditioners&sort=price_low

The unit I am working on is 150

http://www.walmart.com/ip/General-Electric-10-150-BTU-Window-Air-Conditioner-White/34390672
*
NOL any suggestions on sub zero coolant to use?*


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## NoL

You have a few options when it comes to coolant. Water and antifreeze in some proportion works but will still freeze at some temp range that you might be able to reach.
If you are careful (hint flammable) methanol or even ethyl alcohol can be used (vodka cooling!). And then there are designer fluids from 3M you can buy.


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## NoL

You also need to choose what kind of temperature control you want.
Right now you are taking a unit designed to hold 3000w at 70f, and you want it to pump down to 0f or lower. You might really be better suited with some rebuilding.
The proper build would involve a TXV, a receiver and sight glass, and a plate hx. That way the compressor runs in a healthy and well cooled range. A plate hx could still be used in conjunction with a reservoir and PID with relay to give temperature control.


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## Puck

Quote:


> Originally Posted by *NoL*
> 
> You have a few options when it comes to coolant. Water and antifreeze in some proportion works but will still freeze at some temp range that you might be able to reach.
> If you are careful (hint flammable) methanol or even ethyl alcohol can be used (vodka cooling!). And then there are designer fluids from 3M you can buy.










I think it was you that recommended the alcohol to me as well - I was going to use propylene glycol, but it is a lot harder on your pumps since it thickens at low temps.

I am running grain alcohol from the liquor shop, 78% ethyl - strongest I can get legally - for my ~0c cold side loop (without going to lab grade denatured, which adds harsh chemicals and bitterants that I don't want in my loop!). I mixed it with distilled to give what I think ended up being around -40c freezing point (would never go under -20 as-is, I just wanted leeway). I think it came out to 60% alcohol and 40% distilled, but I don't remember the exact measurements...I just ran the numbers through a calculator that predicts freezing point of different percentage alcohols and tossed it in my loop lol.

Just make sure your loop is sealed well since the alcohol will evaporate pretty easily.


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## Chroma

As suggested above, I'd recommend trying an alcohol. They aren't too corrosive. Methanol has a melting temperature of -97C and has quite a low viscosity when compared to water. Your pumps should love it. It doesn't have the same heat carrying capacity as water, but the increased flow rate you'll get from that should, I think, be able to counteract this issue. Just to note, Ethanol melts at -117C, an Isopropanol is -89C. Those also aren't bad choices. Inexpensive, not too corrosive, easy to find.

I was able to get methanol from Fisher Scientific (funny enough, ordered through Amazon). As Methanol isn't something that they are worried about people drinking (like ethanol), they don't put extra "DO NOT DRINK" crap in it. It's uber pure, and rather expensive, though.

Good luck!


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## [ShowMe!]

Quote:


> Originally Posted by *Chroma*
> 
> As suggested above, I'd recommend trying an alcohol. They aren't too corrosive. Methanol has a melting temperature of -97C and has quite a low viscosity when compared to water. Your pumps should love it. It doesn't have the same heat carrying capacity as water, but the increased flow rate you'll get from that should, I think, be able to counteract this issue. Just to note, Ethanol melts at -117C, an Isopropanol is -89C. Those also aren't bad choices. Inexpensive, not too corrosive, easy to find.
> 
> I was able to get methanol from Fisher Scientific (funny enough, ordered through Amazon). As Methanol isn't something that they are worried about people drinking (like ethanol), they don't put extra "DO NOT DRINK" crap in it. It's uber pure, and rather expensive, though.
> 
> Good luck!


Thx man!

I will have some updates in a little while, I have finished my huge 37 gallon reservoir, now I'm working on the new AC, pix will come soon.


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## [ShowMe!]

*I did not give up, here is my new build log, continue in the new thread. LINK*


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