Blog Entry

Valley Forge, PA Finnish Contraflow Masonry Heater: Heat Kit Core, Chimney & Bench Installation

January 27, 2010 by , under Fire Works Masonry News.

The owners of this great room addition designed the new space with energy efficiency in mind. This includes high R value wall insulation and windows, maximizing the solar gain from the southern windows and a clean burning masonry heater fireplace.

The client’s researched wood burning fireplaces online and decided to build a masonry heater. For the core, they were impressed by Masonry Stove Builders’ Heat Kit contraflow core.

Completed Valley Forge Masonry Heater, Heat Kit Core

From the loft, the high temperature concrete capping slabs are visible as well the masonry chimney to the rear. This is a “corner” unit with 45 degree downdraft channels on either side of the loading doors. The clay flue liners in front will be a warming bench. The rectangular holes in the flue tiles are “clean outs” providing seasonal access to clean fly ash out of the heater channels. the masonry chimney is visible behind the heater core.

Valley Forge Masonry Heater Core Top

The flue tiles provide additional heat transfer from the fire’s hot exhaust gases to the masonry stone veneer. The block chimney is located behind the heater. The masonry chimney will transition to a class “A”, double wall metal pipe above the top of the heater.

Valley Forge Masonry Heater, Front Heated Bench

The Heat Kit’s white bake-oven is located directly above the firebox loading doors. The oven is warmed as the hot combustion gases pass over and under the pre-fabricated oven floor and ¬†arched top.

Valley Forge Masonry Heater Core Firebox and Bench

The heater will be faced with 4-6″ native Pennsylvania ledgerock.

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