As the holidays draw near and the days get colder, it’s easy to take for granted how lucky we are to have comfortable, all-day heating in our homes. Many of our current Christmas traditions, like the Yule log, come from ancient festivals and traditions intended to help people stay warm and high-spirited during the coldest and darkest months of the year. If all of human progress has been a piecemeal effort to make our lives more safe and comfortable, then heating technology certainly has an outsized role to play in our story. In honor of the holidays and our upcoming winter wonderland, here’s a crash course on the history of heating tech, from our ancient ancestors to today’s modern marvels.
Ancient Heating Methods
When ancient people first started building their own homes, they used centrally-placed hearths to keep them warm and cook their food. In Eastern Europe, archaeologists have discovered 25,000-year-old Neanderthal houses with hearths made of mammoth bones, and other neolithic structures have been found with the remnants of fireplaces and pits. Ancient houses would generally have holes in the ceiling so smoke could escape, preserving the indoor air quality. Because the fireplace was so important, it was always located in the center of their houses. Even to this day, we maintain the idea of the hearth or kitchen as the “heart” of our homes.
The first people to use a heat transfer system to warm their homes lived in Korea. Their houses had masonry floors that could transfer heat from fires built under the foundations – essentially the same concept as modern-day radiant floor heating. These heated floors, called ondols, have been discovered in archaeological sites dating back to 5000 BCE.
Modern central air heating systems, like the ones in most American homes, have their origins in Roman furnaces called hypocausts. Like Korean ondols, hypocausts used fires built underneath structures to warm them. However, the Romans also used pipes and passages built into the walls to circulate hot air, allowing them to warm rooms on higher stories. These hypocausts are the earliest known forerunners to today’s ductwork-based forced air HVAC systems and were often placed in bathhouses due to the high cost of installing a furnace in a house.
Innovations in Medieval and Renaissance Times
After the fall of the Roman Empire, hypocaust technology was forgotten in Europe for centuries, although more advanced hypocausts continued to be used throughout the Islamic world. In Europe, most people reverted to central hearths to warm their homes. However, in the 13th century, Cistercian monks used a system of fireplaces and river diversions to transfer underfloor heat throughout their abbeys, a forerunner to modern hydronic heating.
During the early Middle Ages, advances in masonry began to allow for more complicated chimneys and stoves to heat houses more efficiently. Early heating stoves first appeared in China in the 1st century. Called kangs, these large ceramic slabs were usually connected to cooking stoves and had complicated flues designed to retain as much heat as possible. Exhaust from the cooking stoves was redirected through the kangs before it was vented outside, allowing people to warm up their houses and keep them warm for hours after they finished cooking. Other early heating stoves were developed in Germany, Russia, and Finland during the Middle Ages. Kangs and other ceramic heating stoves used radiance heating to keep houses warm, somewhat similar to modern radiators and baseboard heaters.
Fun fact – the Medieval era is also when the first Christmas traditions were formed! The Christmas season was officially founded in 567 by the Council of Tours, which declared a 12-day festivity lasting from the Nativity to the Presentation of Jesus. Many modern scholars believe that Christmas was placed in December so Christian churches could co-opt existing solstice traditions like Saturnalia and Yule.
Industrial Revolution and Modern Heating Systems
The first modern central air furnace was invented by a British architect named William Strutt. When he was designing a new mill building in 1793, he included a large stove that heated air brought from the outside through an underground passage. The heated air was then distributed throughout the mill by large central ducts. In 1807, he worked with another engineer, Charles Sylvester, to further refine his idea. The two installed a central furnace in a hospital and designed the ducts so that air was constantly being circulated, allowing patients to breathe fresh heated air while cold stale air was cycled out. This design proved to be highly influential and remained the standard for heating small buildings for the rest of the century.
During the 19th century, many stoves used coal instead of wood to generate heat. Ebenezer Scrooge, the miserly protagonist of A Christmas Carol, is described as having two coal-burning stoves in his London counting-house: one for him, and a smaller one for his long-suffering clerk, Bob Cratchit. Heat was a luxury in Charles Dickens’s London, and the poverty-stricken Cratchit is described as having only a simple hearth in his house.
In 1855, a Prussian-born businessman named Franz San Galli invented the first modern radiator in his St. Petersburg workshop. His invention, which he called the “hotbox,” used a series of pipes that carried steam from a boiler into the room, heating it through the metal pipes. Radiators soon became popular in the US and Europe for their relative affordability. The invention of electric heating by Thomas Edison in 1883 and the first thermostat, created by Warren Johnson in 1885, solidified the landscape of modern heating technology.
Contemporary Heating: Trends and Future Prospects
It has been over 200 years since the basic central air furnace was invented, and heating technology has continued to advance. Today’s furnaces are highly efficient and generally burn natural gas instead of wood, coal, or oil. Modern ductwork runs through most American houses, making central hearths more or less unnecessary – lucky for Santa, who’s far more likely to find an electric faux fireplace than a roaring flame at the bottom of the chimney.
But what about the future? As the clock ticks down to your next furnace replacement, whenever that might be, you may be wondering about cutting-edge heating technology. Today’s most advanced heating units are actually moving away from burning fuel altogether, instead using heat-transferring concepts borrowed from air conditioners. Heat pumps, for example, expand and compress chemical refrigerant to pull heat from the outside and transfer it into your house, while geothermal heating uses heat transferred from deep within the Earth. These new units require only a little bit of electricity to force the refrigerant through the lines, making them highly efficient and environmentally friendly. Heat distribution methods have changed as well, with many homeowners taking a page from the ancient Koreans and using radiant floor heating. Mini-split heat pumps also blow hot air directly into the room, allowing you to skip the ductwork.
If you want to stay on the cutting edge of heating technology this holiday season, you’ll need help from an experienced HVAC contractor. If you’re looking for reliable HVAC service in Napa, Sonoma, Marin, or Lakes Counties, then Next Day Air & Heating is here for you. Contact us today through our website here or by giving us a call at (707) 281-2665.
