The electrical conductivity of the liquid coolant becomes important in a direct cooling application because of the contact between the coolant and the electronics. Other popular non-dielectric coolant chemistries used in indirect cooling applications are propylene glycol, ethylene glycol, ethanol/water, calcium chloride solution, potassium formate/acetate solution and liquid metals such as alloy of gallium, indium and tin (Ga-In-Sn). Deionized water is a good example of a widely used electronic coolant for indirect cooling applications.

Good thermophysical properties for the liquid coolants are required in order to obtain both higher convective heat transfer coefficients and lower pumping power. Most desired liquid coolants’ for electronics cooling applications have good themophysical properties, high flash point and auto ignition temperature, compatible with materials of construction, good chemical and thermal stability, inexpensive, nontoxic and long shelf life. Indirect liquid cooling is where heat dissipating electronic components are physically separated from the liquid coolant, whereas in case of direct cooling, the components are in direct contact with the coolant. Liquid cooling, which can be achieved using indirect or direct means, is utilized in electronics applications having thermal power densities that may exceed safe dissipation through air cooling. By Bojanna Shantheyanda, Sreya Dutta, Kevin Coscia and David Schiemer

Ph level for dex cool coolant