Abstract: A fireplace apparatus for a building includes a firebox, and a plenum arranged with an exterior surface of the firebox. A blower is arranged with the plenum to force air through the plenum and a plenum exhaust vent is configured to release the forced air from the plenum. A method of pre-heating air for a building fireplace includes selecting air admitted from inside the building through an interior inlet port into a manifold and through a plenum until the firebox reaches a selected temperature, and selecting air admitted from outside the building through an exterior inlet port into the manifold and through the plenum when the firebox reaches or exceeds the selected temperature.

Abstract: A modular fireplace burner assembly replacement method comprises providing a burner assembly positioned on a floor of a fireplace, turning off the gas source, decoupling a gas connection of the burner assembly from the gas source, removing the burner assembly from the fireplace, altering the burner assembly, positioning the burner assembly on floor of the fireplace, coupling the gas connection to the gas source, and turning on the gas source. The step of altering the burner assembly may include repairing the burner assembly or one or more subcomponents thereof, performing maintenance on the burner assembly or one or more subcomponents thereof, cleaning the burner assembly or one or more subcomponents thereof, or replacing the burner assembly or one or more subcomponents thereof.