# Need help on Chiller Fluid



## Bradwell

Hello,
this probably should've gone in the regular water cooling section but oh well. Anyway, I need advice on the fluid for my chilled loop. I need one that wont kill my acrylic blocks but will help me go as low as possible. Thank you!


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## Willhemmens

Most people use automotive antifreeze/engine coolant as far as I know.


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## Veltri

The best option that is cost effective is pure or nearly pure ethanol. You can find it in the form of indoor fireplace fuel. I’ve had trouble sourcing legitimate pure ethanol but have taken the fireplace fuel down to -40 with no freeze up. You can also use methanol in the form of windshield wiper fluid but methanol can be dangerous.
Glycol based coolant will start to gel at lower temps and put major strain on your pump.
If you can’t source ethanol at all you can use Everclear drinking spirits but that is pricey.


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## Fisbwp283

Veltri said:


> The best option that is cost effective is pure or nearly pure ethanol. You can find it in the form of indoor fireplace fuel. I’ve had trouble sourcing legitimate pure ethanol but have taken the fireplace fuel down to -40 with no freeze up. You can also use methanol in the form of windshield wiper fluid but methanol can be dangerous.
> Glycol based coolant will start to gel at lower temps and put major strain on your pump.
> If you can’t source ethanol at all you can use Everclear drinking spirits but that is pricey.



What are you using chill the ETOH to -40c?


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## Gilles3000

Veltri said:


> The best option that is cost effective is pure or nearly pure ethanol. You can find it in the form of indoor fireplace fuel. I’ve had trouble sourcing legitimate pure ethanol but have taken the fireplace fuel down to -40 with no freeze up. You can also use methanol in the form of windshield wiper fluid but methanol can be dangerous.
> Glycol based coolant will start to gel at lower temps and put major strain on your pump.
> If you can’t source ethanol at all you can use Everclear drinking spirits but that is pricey.


Unfortunately, ethanol will damage acrylic, as do most solvents.

I believe there are some engine coolants that will still stay fairly fluid at very low temperatures. Another user on the forum just bought a bunch of antifreeze brands and just put samples in the freezer at different ratios to see which gels up the least with the highest water content.(water still hast the highest thermal capacity)


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## ThrashZone

Hi,
Which chiller ?
Home made/ retail ?


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## Fisbwp283

Gilles3000 said:


> Unfortunately, ethanol will damage acrylic, as do most solvents.


Yes it will...but there are also plenty of non acrylic blocks...if you go this way just swap out the blocks.

Acetal is ethanol and methanol safe, as are EPDM and Nitrile...plenty of blocks and o-rings not made from acrylic. Acetal is even ok with Acetone. for that matter there are plenty of full copper/nickle blocks.. also safe with ethanol.

even plenty of reservoirs made from glass which again is safe with ethanol.

your biggest issue is could be your pump choice...which again...even EK lists the materials... Stainless steel, PPS-GF40, EPDM O-rings, Aluminium oxide... all ok with Ethanol.

PPS-GF40 - (Xytron) - which is the impeller mould...again excellent resistance to acetone at and ethanol.


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## Gilles3000

Thermal_Preist said:


> Yes it will...but also plenty of non acrylic blocks...if you go this way just swap out the blocks.
> 
> 
> Spoiler
> 
> 
> 
> Acetal is ethanol and methanol safe, as are EPDM and Nitrile...plenty of blocks and o-rings not made from acrylic. Acetal is even ok with Acetone. for that matter there are plenty of full copper/nickle blocks.. also safe with ethanol.
> 
> even plenty of reservoirs made from glass which again is safe with ethanol.
> 
> your biggest issue is could be your pump choice...which again...even EK lists the materials... Stainless steel, PPS-GF40, EPDM O-rings, Aluminium oxide... all ok with Ethanol.
> 
> PPS-GF40 - (Xytron) - which is the impeller mould...again excellent resistance to acetone at and ethanol.


I know, but OP specifically asked for a coolant that won't damage his acrylic blocks, so I'm pretty sure he wants to keep them.


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## Veltri

Thermal_Preist said:


> What are you using chill the ETOH to -40c?


Home built chiller.


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## Veltri

Gilles3000 said:


> Unfortunately, ethanol will damage acrylic, as do most solvents.
> 
> I believe there are some engine coolants that will still stay fairly fluid at very low temperatures. Another user on the forum just bought a bunch of antifreeze brands and just put samples in the freezer at different ratios to see which gels up the least with the highest water content.(water still hast the highest thermal capacity)


True. But acrylics really aren’t suitable for chillers anyway. If OP wants to play around near dew point, sure, they will work. But the real low temperatures will destroy off-the-shelf water cooling components regardless of the coolant. The waterblock on my chiller is fully brazed shut and all copper. It looks a lot like an evap from a phase unit. No O rings or gaskets or plastic parts anywhere. They just don’t hold up to low temps.


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## J7SC

OP - check out Linus' chiller vid below, specifically the 'RainX'...worth checking the manufacturer's site re. compatibility with acrylic, plastics and such


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## Master Chicken

I think THIS is probably the best solution when mixed with water. I'm pretty sure @toolmaker03 did testing with various concentrations at low temps in one of his threads a few years back. At the time, I saved the link to the Propylene Glycol on Amazon ... but sadly, not the thread location.


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