The scientists developed a new method to predict how thick liquids like refrigerants are. They collected data on 14 types of refrigerants and used a special equation and friction theory to create a model. By crunching the numbers with this model, they found that their predictions for how thick the refrigerants were in both gas and liquid form were very close to the actual measurements. This means the method is accurate, with tiny errors of less than 1% for gases and between 0.31% and 1.92% for liquids.