Line Set

Related terms

• Condenser

  The outdoor unit that rejects heat removed from the house. Needs clearance and airflow; undersizing or dirty coils kill efficiency.

• Refrigerant

  The working fluid that carries heat in an AC/heat pump. R-410A is being phased down to lower-GWP refrigerants (e.g., R-454B) under EPA ru…

• 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.

• Knob-and-Tube Wiring

  Obsolete early-1900s wiring with no ground. Often must be replaced during remodels and can affect insurance and insulation.

• Load Calculation Oversizing

  Installing equipment larger than the calculated load — a frequent mistake that causes short cycling, poor dehumidification, and higher cost.

• Junction Box

  An enclosure where wires connect; all splices must be in an accessible box, never buried in a wall. A common code violation in DIY work.

• Main Breaker

  The single breaker that disconnects the entire panel and caps total service amperage.

• Hydronic Heating

  Heating that circulates hot water through baseboard, radiators, or floor tubing. Comfortable and quiet; slower to respond than forced air.