static

I'm a big dummy when it comes to my own air conditioning maintenance. I talk about the importance of changing air filters to customers and techs, but I never stay up on replacing my own. Yesterday, I walked into my mechanical room, and my 2-ton air handler sounded like a vacuum cleaner about to implode. […]

When you start talking airflow, it can get pretty in-depth pretty quickly. There is a big gap between what is useful for the average tech to apply every day and the whole story, so let's start with the simplest part to understand, static pressure. Static pressure is simply the force exerted in all directions within […]

We've been pretty spoiled in residential and light commercial in the USA because we haven't needed to deal with glide much. R22 has no glide, and R410a is a near-azeotropic blend, which means it has almost no glide. The days of being able to ignore glide are coming to an end. Carrier has announced their […]

This article is written by one of the smartest guys I know online, Neil Comparetto. Thanks, Neil! Recently, I posted a question in the HVAC School Group on Facebook that went like this: “When designing a residential duct system, what friction rate do you use?” As of writing this, only one answer was correct according […]