Connecting more than one wire on or under a single lug or connection point is called “double lugging,” and it is ONLY allowed in line voltage wiring under one condition, according to NEC 110.14: If the terminal, lug, or connector is specifically rated for more than one wire In the case of a conductor splice, […]

The primary role of setting an appropriate level of subcooling is to ensure that we deliver a full line of liquid refrigerant to the metering device. We want to do this at: A pressure differential required by the metering device At a temperature and pressure no higher than required for maximum capacity and efficiency But […]

A lot of proper duct design comes down to an understanding of available static pressure and friction rate. We've covered this topic several times on this site and the podcast, but I wanted to focus on this ACCA chart specifically (shown above). If you want a deep dive, I highly recommend listening to my podcast […]