The title is a serious question. I have a computer located in the loft of an outdoor shop. The shop and loft are unheated and during the winter, the temperature can easily fall below freezing in the loft.

What happens to the liquid in the liquid cooling system for the CPU when the temperature is below freezing?

It turns out “it depends”: some liquid coolers use water, others use various additives including an anti-freeze material. The only way to know for sure is to contact the cooler manufacturer.

My CPU cooler is an Enermax Aquafusion 240. I contacted their tech support center, who did not immediately know the answer but graciously forwarded the question to their headquarters who got back to me and let me know that they had tested it in the lab down to -15 degrees C (or about +5 deg F).

That’s good information to know! And a big thank you to Enermax for pursuing an answer to that question!

By EdwardM