Manual J Load Calculation

Related terms

• Load Calculation (Electrical)

  An NEC calculation of total demand to verify the service/panel can carry added loads. The basis for whether a service upgrade is required.

• 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…

• Manifold / Home-Run

  A PEX distribution method with individual lines from a central manifold to each fixture, improving pressure balance and isolation.

• Meter Base

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

• Make-Up Air

  Replacement outdoor air supplied when powerful exhaust (large range hoods, whole-house fans) depressurizes a house. Code-required above s…

• NEC (National Electrical Code)

  The model electrical safety code adopted (with amendments) by jurisdictions. Permitted electrical work must meet the adopted NEC edition.

• Main Shutoff Valve

  The valve stopping all water to the house. Every homeowner should know its location; remodels often add accessible zone shutoffs.

• P-Trap

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