Ancient HVAC: The Story of an Ephesian Goddess, the Roman Baths and Pliny the Elder’s Possibly Grues
If this sounds like an unlikely historical timeline, don’t worry, it’s not. This glance back at history begins with the Greeks, who not only gave Western civilization democracy, medicine, astronomy, mathematics, philosophy and the Olympics, but also pioneered warm winter nights by inventing the first central heating system.
Let’s begin at the sacred Temple of Artemis, built in tribute to the Ephesian goddess of fertility. At least twice the size of the Parthenon and one of the first Greek temples to be constructed entirely of marble, the remains of the temple are a popular tourist destination celebrated today as one of the Seven Wonders of the World.
Known in part for its once-soaring ionic columns, 127 of them in all if you believe the writings of ancient Roman philosopher and historian Pliny the Elder, the Temple of Artemis also happened to house the earliest version of central heating known to mankind. Two architects from Crete, Cherisiphron and his son Metagenes, designed the magnificent, columned temple and its clever heating system around 550 B.C. in Ephesus, located on the coast of the Aegean Sea in what is now modern-day Turkey.
According to the father-and-son team’s design, heat generation relied on a wood-fired furnace continuously tended by slaves in the basement of the temple. Hot air from the fire was forced into pipes laid underneath the floor. As the stone floor warmed, it yielded heat into the air above, keeping occupants warm from the bottom of their tootsies to the tops of their tunics.
This first-generation central heating concept was later improved upon by the Romans, who dubbed it a hypocaust (Latin: hypocaustum). Similar to the original Greek design, the hypocaust also relied on an underground fire manned by slave labor. But Roman designers took the concept a step further. Engineers raised the floors of the wealthiest Romans on terracotta, brick or early-concrete pillars about 2’ high, allowing room for hot air to circulate in the space below. Not only did this warm the tile floor, ceramic tile ducts built into the walls held heat and helped to circulate warm air to the rooms above.
Centuries later, hypocaust engineering was used to heat Italy’s most famous public baths in Rome and Pompeii. The latter metropolis purportedly saw the grim, ash-covered end of our friend Pliny the Elder when Mount Vesuvius erupted in A.D. 79. This part of the story may or may not be true. At the very least, Pliny did lead a rescue operation by boat across the Gulf of Naples to Pompeii as clouds of smoke and ash poured from the volcano. Just 56 at the time, he was never seen again.