No one fluid is ideal for all uses. A brief survey of three basic groups -- petroleum-based, synthetic aromatic and specialty fluids -- outlines the general characteristics of each type.
I have in my office information on approximately 70 different thermal fluids, and every time I think that I have them all, I learn about another. The variety of fluids available to the end user is staggering, and each supplier advertises his fluid as “the best.” So, what fluid is best, or at least a good choice for a particular application? A brief survey article can't answer that question specifically, but it can give the reader a general understanding the sources of fluids.
Understanding the vast number of fluids is simplified by arranging the fluids into groups. This article will group fluids into three basic sets -- petroleum-based fluids, synthetic aromatic fluids and specialty fluids. Petroleum fluids can be further divided into mineral oils and technical white oils. The white oils are interesting in that they can be further divided, as will be seen.
Glycol and polyglycol fluids, along with molten salts, will not be discussed in this article, but will be in later articles.
Note: This article will mention typical fluids in each class. Noting a specific fluid should not be taken as a preference or recommendation, but rather an association of familiar brand names to assist the reader's understanding.