Praefurnium

In Ancient Rome, the praefurnium designated the room and the furnace that ensured the heating of the hot or warm premises of the thermae.

The water is heated in copper or bronze tanks above the furnace combustion chamber.

[2] The heating of the premises is also done by hot air distribution ducts called tubuli.

These are elements of terracotta ducts of different shapes, allowing the circulation of hot air from the hypocaust to the upper parts of the thermal baths.

[3] The heating room has an opening on the ignition and fuel reserve side, as well as for the supply of fresh air and another opening on the side of the hypocaust, for the exit of smoke and gas as well as hot air.