Sciencemadness Discussion Board

How cold is it?

QueerSquadLeader - 20-3-2011 at 20:22


hkparker - 20-3-2011 at 20:34

Pretty darn cold!

Was this post an accident? If not please be a little more specific :D

But seriously.... detritus?

QueerSquadLeader - 20-3-2011 at 21:19

Sorry about that!
I am curious about a chiller i'm building, i've taken a window A/c unit removed the low side fan and put the condenser in a container filled it with 60% water 30% ethylene glycol and 10% methanol and a pump which goes to my glassware. its cold but i am curious if it will reach -78C and appreciate any advice on how to reach that temperature
thanks

hkparker - 20-3-2011 at 21:21

I see. Im not sure how cold that would get in theory and im sure it depends on other factors about the design of the a/c unit. Why are you trying to get to -78? Thats the temp of dry ice/acetone baths.

Contrabasso - 21-3-2011 at 00:29

Best I can find ATM is that the lower limit for using antifreeze solution in engines is -37C so you have another 40+ degrees to go to reach your target temperature using glycol and water.

See that the fluid is suitable before you try to cool it too far.

Remember that the freezing point of antifreeze is below that of glycol or water.

Be very careful that everything on the cold side is safe for running at the low temperatures you want. Things will attract condensation which will freeze and maybe prevent rotation or other function.

smuv - 21-3-2011 at 09:57

No, you will not reach -78c.