The Four Ps of IAQ I’m not the first, second, or probably even the thirty-second person to write about improving indoor air quality problems using the four Ps approach. It’s a well-known thought process in the building science community—not sure if that’s the case in HVAC circles. The first P is for pollutants. In this […]

The HVAC industry uses all sorts of fancy words to classify refrigerant. As such, there are all sorts of complicated refrigerant acronyms: HFC, HCFC, CFC. Let's also not forget the mythical zeotropic, azeotropic, and near-azeotropic descriptors. Let's simplify those. (Though if you want to go back to the basics first, check out this article on […]

Over the years, I have heard technicians say that refrigerant can wear out or “lose its blend” by sitting in a tank. Refrigerant does not wear out or “lose its blend”… at least not like that. What can and does happen is called “fractionation.” Refrigerant blends are composed of a mix of refrigerants with different […]