First-Hour Rating / GPM

Related terms

• Flue / Venting

  The pipe carrying combustion gases safely outside. Improper sizing, slope, or material is a serious carbon-monoxide hazard.

• Feeder

  The conductors carrying power from the main panel to a subpanel or large appliance disconnect.

• Fuel Conversion

  Switching an appliance/home between gas, propane, and electric. Affects venting, gas sizing, electrical service, and rebate eligibility.

• Expansion Tank

  A small tank absorbing thermal expansion on a closed system (with a backflow preventer/PRV). Code-required in many areas to protect the h…

• Furnace

  A forced-air heater burning gas/oil or using electric elements, distributing heat through ductwork. The most common U.S. central heating…

• Evaporator Coil

  The indoor coil (usually atop the furnace) where refrigerant absorbs heat from house air. Paired and matched to the condenser.

• Galvanized Pipe

  Old zinc-coated steel supply pipe that corrodes and restricts flow internally. A common reason older homes need a repipe.

• ERV / HRV

  Energy/Heat Recovery Ventilators that supply fresh air while recovering heat (and, for ERV, humidity) from exhaust. Key for tight, health…