Rumford fireplace visit

I am fascinated by the concept of a Rumford fireplace; an open hearth that sends more heat into the room than it loses to combustion air, and one that charges the thermal mass around it to store and release heat radiantly (and conductively, depending on the design) long after the fire is out. I have built an outdoor Rumford, and have helped with another outdoor model and an indoor proof-of-concept retrofit, but I have not yet had the pleasure of enjoying a fire in a full-blown masonry fireplace of this type.

Last weekend, my family and I had the chance to visit some folks not far from where we live who have a Rumford fireplace in their off-grid strawbale home. They lit it up for us and, wow, it was a revelation. The room, already comfortably warm on that chilly night, became instantly cozy, with a handsome and robust fire blazing in the hearth. The fire hugged the back of the fireplace, and smoke was whisked up the chimney without straying from the amazingly shallow firebox.