Friction rate is a value located on a ductulator. We use it during the design phase of a duct system to predict the operating static pressure of a duct system. The challenge with friction rate is that it is often misapplied by folks using a rule of thumb (ROT). In order to apply friction rate properly, […]

This tech tip comes from our contributor, compressor decapitator, and super tech Ulises Palacios. Many ductless systems and some high-efficiency unitary systems have electronic expansion valves. If you find one that is stuck closed, you may be able to get it open temporarily by putting a strong magnet like the one shown above on the […]

This is a subject that even many commercial guys don’t have to consider. For the majority of equipment, even refrigeration equipment, all that is required for proper oil return is to size the suction line properly, trap the suction line as needed, and allow for proper slope towards the compressor. Then we get into larger […]