Hypocaust

A replica of a Roman underfloor heating system, known as a hypocaust, can be found in the old town of Mainz near Schillerplatz.

Anyone looking at the remains of the Roman hypocaust in the park between the Institut Français Mainz and the Proviantmagazin today would hardly guess the sophisticated technical expertise behind it.

Hypocaust at a glance

Historical

The idea for a type of underfloor heating actually originated with the Greeks (Greek hypocauston = "heating from below"). The floor, which was often richly decorated, was supported by small pillars. A wood fire distributed its heat in the channel-like passages created directly under the floor, ensuring pleasant temperatures of around 25 degrees Celsius.

Underfloor heating was part of the advanced Roman building culture, which also already had an industrialized brick industry.

Thermal baths and bathing culture

The hypocaust was often equipped with wall heating, through whose chimney-like shafts the smoke from the fire could escape to the outside. Only a few rooms in a Roman residence of a higher standard featured this intelligent heating system. Due to the large consumption of wood or charcoal, the heaters were very energy-intensive.

This heating technology was therefore mainly used in Roman baths, which were just as sophisticated as the hypocaust technology. The bathing rooms sudatorium, caldarium, and tepidarium differed in their temperature levels. There were also swimming pools, gymnasiums, and even libraries. However, in keeping with the ancient need to bring body and mind into harmony, men and women were only allowed to pursue this goal separately.

Excavation

During the construction of the Schillerplatz parking garage in 1979, archaeologists discovered the remains of a Roman residential building with underfloor heating several meters below the current street level. The model reconstruction of such a hypocaust in the park refers to this discovery. It illustrates how the heating system worked.

Architecture

The reconstruction shows the shell masonry of the house walls made of limestone blocks. The interior is equipped with a heating system in the form of a cavity under the actual floor. Low pillars made of small square or round bricks, standing close together, support a brick slab covering, which is additionally covered with screed. Together they form the floor.

A fire is lit in an external boiler room. The hot air produced flows through a connecting duct into the cavity, heating the brick slab floor from below. The floor distributes the heat evenly into the room above.

Today

The remains of the hypocaust can be viewed in the park on Schillerplatz, next to the Proviant-Magazin.

Contact us

Address

Hypokaustum

Schillerstraße 34-36
55116 Mainz

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