Looks very similar to the kinds of oven stoves and heat walls in https://www.lowtechmagazine.com/2008/12/tile-stoves.html https://www.lowtechmagazine.com/2008/1

Looks very similar to the kinds of oven stoves and heat walls in https://www.lowtechmagazine.com/2008/12/tile-stoves.html https://www.lowtechmagazine.com/2008/12/tile-stoves.html, which I found quite inspiring.