Roman Heated Floors

Roman heated stone floors.

Roman heated floors.

Hypocaustum is a system of central heating in a building that produces and circulates hot air below the floor of a room and may also warm the walls with a series of pipes through which the hot air passes. Underfloor heating and cooling is a form of central heating and cooling which achieves indoor climate control for thermal comfort using conduction radiation and convection the terms radiant heating and radiant cooling are commonly used to describe this approach because radiation is responsible for a significant portion of the resulting thermal comfort but this usage is technically correct. The floor was raised above the ground by pillars called pilae stacks with a layer of tiles then a layer of concrete then another of tiles on top. Hypocausts were used for heating hot baths thermae houses and other buildings whether public or private.

Roman houses with a hypocaust system had a furnace that would heat the air. This air can warm the upper floors as well. Smoke was prevented from entering the room by. The word derives from the ancient greek hypo meaning under and caust meaning burnt as in caustic.

In the wealthiest citizens homes the walls and floors were buttressed by slim chambers called hypocausts. And spaces were left inside the walls so that hot air and smoke from the furnace would pass through these enclosed areas and out of flues. During the roman empire the art of natural stone flooring reached new heights of innovation. Masterful roman architects were able to design a series of floors that were actually heated from below.

This short 3d visualisation shows how the roman hypocaust heating system worked. These were the first below surface radiant heating systems. The floor was raised above the ground by pillars that were called pilae so that hot air could circulate under it the floor consisted of a layer of titles followed by a layer of concrete then another layer of tiles.