Recommended Duct Velocities (FPM) Duct Type Residential Commercial / Institutional Industrial Main Ducts 700 – 900 1000 – 1300 1200 – 1800 Branch Ducts 500 – 700 600 – 900 800 – 1000   As service technicians, we are often expected to understand a bit about design to diagnose a problem fully. Duct velocity has many […]

This tip was a COMMENT on the sensible heat ratio tip left by Jim Bergmann. As usual, Jim makes a great point; once you get the “sensible” capacity for a piece of equipment at a set of conditions, you can easily calculate a true target delta T. Another interesting thing you can do is use […]

Let's start with the basics. Water freezes at 32° Fahrenheit (0° Celsius) at sea level and at atmospheric pressure. When any surface is below that temperature, and the air around it contains moisture, ice/frost will form. In some situations, ice is to be expected, such as in refrigeration evaporators and exposed portions of the refrigeration […]