/——-/ I don’t know. I just remember my friends who had fireplaces in their 1940s homes who had them. They did capture a lot of heat. Good luck.My problem, is this old fashioned colonial era, walk in fireplace....we can't find A fireplace insert big enough to fit!!!!!!!!!!!
It would take A whole bunch of masonry perhaps, to make it smaller somehow, to fit A smaller insert with blower??