May 30, 2008 by Brian Klipfel, under Fire Works Masonry News.
This Finnish contraflow heater is the centerpiece of a living room addition to this Hillsborough, NJ home. The family spend most of their time in this room conveniently beside the expanded kitchen. The well insulated space stays comfortable all winter with the soft heat radiating from the Pennsylvania field stones. The blue stone hearth before the loading doors is also from a local Pennsylvanian quarry.
The heater’s efficiency starts with the well designed and thoroughly tested Heat Kit core. The core is surrounded and slowly releases it’s stored energy created by the intense fire into the veneer stones. Here we see the core wrapped with a fiberglass blanket to allow for thermal expansion. The stone facade is about halfway completed at this point. A wooden form creates the open space for the later installation of the loading door. Similarly, the two lower small foam pieces hold the opening for the clean out doors. The doors provide seasonal access to the two side downdraft channels to clean any of the fine fly ash from the intense heater burn.