ME 350X_Assignment 3 Power

Power Essay

Roman Hypocaust Systems.

Ethan Keyser

ME 350X History of Technology

16 October, 2014

H.R. Statement: Yes, I used the online resources cited in my footnotes, as well as library resources.

There is no debating that the romans were great engineers and architects.  The Romans created many of the inventions that are still relevant in modern times.  They also built many large-scale projects such as the Great Coliseum or their extensive road network, that still stand today.  One invention of the Romans that is often overlooked is the hypocaust system.

The hypocaust system was a “heating system to heat multiple rooms simultaneous by heating the floors and walls.  This very simple system consists of furnace, raised floor supported by columns or multiple tiles, and chimneys.  The raised floor creates duct-like channels for heat to travel.”[1]  The “ductwork” underneath the floors and in the walls allowed for air heated by the furnace to circulate throughout heating several different rooms or spaces at once.  This system made it much easier for the Roman baths to be kept at a consistent warm temperature.

In addition to heating large areas at once, the hypocaust systems allowed for varying degrees of heat in each room.  “The hottest room in Roman buildings could reach up to temperature of 120 degrees F.  For this temperature, at least three walls had to be heated in addition to the floor.  The number of walls heated and the distance from the furnace determined the temperature of the room.”[2]  In order for the hypocaust to effectively heat the rooms, the substructure of a roman bathhouse had to be carefully planned.  “Ventilation of the service area was crucial, for the fires without adequate convection would burn poorly.  Airshafts, which also served as light wells, were therefore a regular feature of the galleries vaulting.  Hypocausts tended to cover the full extent of the floors above them, running just above the subfloors of the heated rooms.”[3]  Even visiting the sites of the old Roman bathhouses today, it is easy to see the complexity with which they were designed.

To add, although they were primarily used in bathhouses, the hypocaust system was used elsewhere.  “Many examples of such hypocausts exist in villa and house foundations in Roman centers in Germany and England.”[4]  In many ways, the Roman’s created the precursor to modern indoor heating, and by way of building bathhouses and villas throughout their empire that utilized the technology, they spread it to many different people.

Some of the specifics for a hypocaust system were “for maximum efficiency of heated air travel, the floors are raised two feet above the ground.”  This spacing was achieved by stacks of tiles spaced throughout the subfloor.  In addition to supporting the floor above, the tiles retained heat from the hot air and helped regulate temperature.  To continue, “The most efficient height of the fire that will allow more air to enter and carry the heat is half the furnace height”[5] As mentioned earlier, maintaining a consistent burn with the fires was very important for the hypocaust system.  “The usual custom was to lead the hot air from a hypocaust into a single vertical flue in the wall of the room to be heated, through which the hot air and smoke escaped into the open air. Where greater warmth was desired, several flues would lead

up from the hypocaust in the side walls of the room; at times these wall flues consisted of hollow, oblong tiles, set close together, entirely around the room.”[6]  These design features reflect the ingenuity of their roman creators.  Examples of each of these features can be found in structures all around the former roman territory.

One of the major problems that existed with the Hypocaust system was that the fires in the furnaces would create the poisonous gas carbon monoxide.  This gas would then travel all throughout the building through the Hypocaust.  Because of this it was of extreme importance that all the rooms be sealed off from the heating system.  Another problem with the system was that the system would loss heat as the air travelled from room to room.  This made it a necessity that the hottest rooms would be those closest to the furnaces, and the coolest rooms would be those farthest away.  The large bathhouses would also have multiple furnaces to help heat the far rooms.

The roman hypocaust systems were truly a feat of modern engineering, using ductwork, and relying on the natural heat transferring properties of may different materials, the Romans were able to create a very modern luxury in the classical world.