I am not an expert in the field, but a quick look through the product pages at 3M suggests that the important difference is the boiling point. Novec boils at 49

I am not an expert in the field, but a quick look through the product pages at 3M suggests that the important difference is the boiling point. Novec boils at 49 degrees C, so for cooling electronics the primary mode of heat transfer will be the phase change. Fluorinert seems to boil at higher temperatures, 80 and > 200 degrees for the two variants I looked at. They seem to be in the same family of products and several of their physical properties are very similar, so maybe they're just variants. Here's a link to a page which has both families: http://www.mgchemicals.com/products/cleaners/3m-fluids/ http://www.mgchemicals.com/products/cleaners/3m-fluids/