Patent ID: 7662304

Claim:
A corrosion inhibiting heat transfer fluid for use in a heat transfer system, comprising a corrosion inhibitor comprising an azole compound, and a siloxane based surfactant, or a mixture of a siloxane base surfactant and colloidal silica, the corrosion inhibiting heat transfer fluid having a conductivity of no more than or equal to 200 uS/cm, wherein the siloxane based surfactant comprises a polysiloxane of the general formula R 3 —Si—[O—Si(R) 2 ] x —OSiR 3 wherein R is an alkyl group or polyalkylene oxide copolymer of from 1 to 200 carbons and x is from 0 to 100, and the polysiloxane has at least one R group that is a polyalkylene oxide copolymer of one or more alkylene oxides having from 2 to 6 carbons.