Why is it essential to provide a load calculation before retrofitting a new heating and cooling system in an older house? To make sure the right size systems get installed, use Manual S. To design the ...

What is a load calculation? A load calc determines just how much heating and cooling is needed for a specific house or building. It takes the guesswork out of sizing HVAC equipment. Its methods have ...

The electrical panel, also known as the service panel, is the control center for all the electrical circuitry in a residence. Today’s panels are bigger than earlier versions. They have to be, because ...

A multifamily dwelling is one that contains three or more dwelling units [Art. 100]. Though similar, single and multifamily dwellings have distinct differences. The wiring method used for a ...

Note: This article is based on the 2002 NEC. Even if you work with stamped drawings, you'll eventually need to do commercial load calculations in the field or on a licensing exam. The National ...