Drain-Waste-Vent (DWV)

Related terms

• Dual-Fuel / Hybrid System

  A heat pump paired with a gas furnace that switches to gas in extreme cold for the most cost-effective heating across the season.

• Dimmer Switch

  A control varying light level. Must be compatible with the bulb/driver type (LED-rated) to avoid flicker and buzz.

• Duct Sealing

  Mastic/foil-tape sealing of duct joints to stop leakage (often 20–30% of conditioned air). One of the highest-ROI efficiency improvements.

• Dehumidifier (Whole-House)

  A ducted unit removing humidity in muggy climates/basements for comfort and mold control beyond what AC alone provides.

• Ductless Mini-Split

  A heat pump with an outdoor unit and wall/ceiling indoor heads, no ductwork. Ideal for additions, conversions, and zoning specific rooms.

• Dedicated Circuit

  A circuit serving one appliance only (e.g., range, dryer, microwave, EV charger). Required by code for many large or motor loads.

• Ductwork

  The supply/return passages distributing conditioned air. Leaky or undersized ducts are a top cause of comfort and efficiency complaints.

• Damper

  An adjustable plate in a duct that balances or shuts off airflow to a zone or branch.