Water Cooling Equip. and Performance Guide – Fluids

This content was originally featured on and has been converted to PC Perspective’s website. Some color changes and flaws may appear.

Welcome back to the third article in our water cooling series where we’ll be discussing the topic of fluids. Our goals for this article include determining what fluids are acceptable for use in computer cooling and figuring out how much flow we need. For laughs we’ll also look at some alternative fluids that may be used in extreme cooling projects.

The fluid is what really gets the job of transferring thermal energy accomplished. In the human analogy, the heart is the pump responsible for moving blood, but the blood handles the task of carrying nutrients, waste, oxygen, and carbon dioxide around the body. In the computer, the fluid picks up heat from heat sources such as the CPU, GPU, and chipset (and as we saw earlier, from the pump) and expels this heat via a radiator or other cooling means.

There are only a few properties that are important for the fluid to do its job. First, it should have good specific heat. Specific heat is a measure of how densely a fluid can store thermal energy. A fluid with high specific heat does not require much flow or temperature change to move a lot of energy. Second, the fluid must have an acceptable viscosity. Viscosity largely determines how easy it is to pump the fluid and also affects how efficiently the fluid will pick up and drop off the energy it must move. Third, the fluid must not cause undue distress to the rest of the computer including the cooling system. Among the possibilities are leakage, corrosion, fouling, and deterioration of cooling components.

I’ll tell you again that I’m an engineer. I am neither a chemist nor a biologist. My knowledge in the areas of problems that may occur with fluid fouling is limited. Based on my own experience and reading, I’ll include some recommendations for keeping your fluid in good shape but I’ll also encourage you to do your own additional research in this area.

For much of the remainder of the article, I’m going to be using the properties of water to calculate some relevant information. Various additives to reduce corrosion or extend useful fluid life do not normally alter the heat transfer properties much. Only at the end will I delve into some of the funky alternatives that exist.

« PreviousNext »