For centuries keeping the chill of winter at bay was accomplished by stacking wood, and by rubbing two sticks together or using a flint, starting a fire. The shortcomings were evident regardless of whether the fire was in a cave or fireplace; one side baked while the back side froze. The first major step toward modern heating was made by the Romans.
The words were derived from Greek but the engineering was Roman brilliance. Hypocaust, hypocaustum in Latin, derived from the word “hypo” which means “under” and “caust” which means “burnt” was an engineering marvel that was essentially a primitive form of central heating. It was also costly and as a result its use was largely restricted to the homes of the wealthy, public baths, and in rare instances, some government buildings.
The system had to be incorporated into new construction rather than applied to older homes as it required the ground floor to be raised and supported pilae or pillars that allowed for heated air to circulate under the floor. This also required specially constructed floors; a layer of baked tiles, a layer of concrete and then a layer of glazed decorative tiles. In the walls there clay flues which allowed the heat to be distributed to the second story while heating the room below. Walls were often finished with glazed tiles to better hold the heat, and to provide a degree of insulation.
A primary challenge was to ensure that smoke from the wood fired furnace under the floor did not leak into the house. The Romans were well aware of the poisonous gasses associated with smoke. Another challenge was in the engineering of the flues to ensure that one room did not become a furnace and others were chilled.
Public baths were an integral part of Roman social life. In these buildings a special furnace room, or caldarium in Latin, was built. The architect Vitruvius wrote about this specialized construction in great detail in a book entitled De architectura. He explained that fuel could be best utilized by building the furnace room for the men’s bath in a manner that enjoined it to the bath for women. The Pompeii Old Baths remain as an example of how these baths were constructed.
For home or public use, the hypocaust was expensive to use and to maintain. Slave labor was trained in operation and maintenance, vast amounts of wood was required, and it required constant supervision when in operation. As an interesting historic footnote, after the collapse of the Roman Empire, central heating for homes was not available until the early 20th century. And even with modern materials and equipment, archaeologists have had tremendous difficulty in trying to duplicate this Roman heating system.
Fortunately keeping the chill of winter has never been easier. One call to AIRzona Comfort Solutions is all that is needed to ensure your home is warm in the winter and cool in the summer.
Written by Jim Hinckley of Jim Hinckley’s America