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 […]

This topic came up because I was testing out the new MR45 digital recovery machine. That machine goes off by itself when it hits a 20″ Hg vacuum. It's a cool feature, but it is good to know when that level of vacuum is overkill and when it's not enough according to EPA requirements. You […]

This article is a year old, and I'm recycling it because it's on my mind today. I had a fun conversation with Richard Trethewey on the podcast that has me thinking along these lines today. The link is HERE if the player isn't showing up. I have a confession to make. I'm a bit of […]