NEC (National Electrical Code)

Related terms

• Permit

  Official jurisdiction authorization to perform regulated work, triggering required inspections. Unpermitted remodels can force teardown,…

• P-Trap

  The U-bend at each fixture holding water that blocks sewer gas from entering the home. Every fixture needs one, properly vented.

• Meter Base

  The utility meter socket on the service entrance; replaced or relocated as part of a service upgrade.

• Permit & Inspection (Mechanical)

  HVAC, gas, electrical, and plumbing work is permitted, inspected trade work. Unpermitted mechanical work is a safety and resale liability.

• MERV Rating

  Minimum Efficiency Reporting Value — a filter's particle-capture rating (1–16). Higher filters more but can choke airflow if the system i…

• PEX

  Cross-linked polyethylene supply tubing — flexible, freeze-tolerant, fast to install with fewer joints. The dominant modern repipe material.

• Manual J Load Calculation

  The industry-standard room-by-room heating/cooling load calculation that correctly sizes equipment. The right basis for any system replac…

• Plenum

  The main air chamber off the furnace/air handler from which supply ducts branch and into which the return delivers.