A brief history of central heating…
When it comes to keeping warm, we’re a bit spoilt.
Our heating systems are so good, we don’t even give them a second’s thought most of the time. They’re the unsung heroes of our home, keeping us comfortable all year round.
And not only that, they’re smart too. We live in a time where our heating systems can actually ‘learn’ things about us – from what temperature we like, to our daily schedule.
With geo-fencing technology, they can even tell when we’ve left the house, or are about to return, so that they can get the temperature just to our liking – without us lifting a finger! But it wasn’t always like this!
We’ve come a long way from the campfires of early man.
In this blog, we look back at the history of central heating. So we can really appreciate how far we’ve come – and where we may be headed in the future.
As you’ll appreciate, the history of central heating across the world is a long one, so we’ll keep it to the brief and edited highlights!
Campfires were used for heating and cooking.
These fires began outside, but were eventually moved inside the home, when it was realised that openings in the roof would allow the smoke to escape.
Although we tend to think of underfloor heating as a modern invention, the very first form of underfloor heating dates back thousands of years to North Korea.
Known as an ondol – meaning ‘warm stone’, homes were warmed by allowing the fire in the furnace of a kitchen to pass under the room’s floor to keep it warm.
The Ancient Greeks invented the first fixed central hearths for keeping homes warm.
The hearth commonly stood in the middle of the room, with the smoke rising through the room to a smoke hole in the roof.
The hearth was used for cooking on, as well as keeping the home warm. Such was the significance of the hearth to the home, Greek and Roman mythology features goddesses of the hearth, Hestia and Vesta.
The Ancient Egyptians introduced bellows which created a strong blast of air to fan the flames and enhance the heat of fires. But the first real central heating system didn’t come along until the Romans.
350 BC – The Romans
It’s nigh on impossible to talk about the inventions of the Romans without thinking of the infamous line in Monty Python’s Life of Brian:
“All right, but apart from the sanitation, the medicine, education, wine, public order, irrigation, roads, a fresh water system, and public health, what have the Romans ever done for us?” …
But we could certainly add to it – invented the first central heating system!
The Roman Empire invented a heating system called a “hypocaust” for heating hot baths and other public buildings in ancient Rome.
Roman buildings with a hypocaust were built on pillars and the floors and walls had spaces in them.
By lighting fires below the buildings, heat could flow through the space in the floors and walls, and out through flues in the roof.
476 AD – The Collapse of Ancient Rome
The fall of the Roman Empire saw the decline in the Hypocaust, and home heating largely reverted to being handled by fireplaces in individual rooms. It wasn’t until around 1,500 years later that central heating was reintroduced.
800 AD – The Early Middle Ages
During the Middle Ages, both stone and clay ovens were used.
The 12th century – Invention of the chimney
The first chimneys were constructed in castles. The earliest extant example of an English chimney is at the keep of Conisbrough Castle in Yorkshire, which dates from 1185 AD.
The 13th century
In the late 13th century, chimneys in domestic homes started to make an appearance.
Holes in rooves that had previously been used to allow smoke from the hearth to escape were enclosed by a board, known as louvres.
These boards were made of horizontal wooden planks, fixed diagonally and an opening for the smoke to escape.
The 15th century
The first masonry stoves were built.
The 17th century
The wood burning fireplace was the primary means of heating a home. Louis Savot of France invented the raised grate and designed a circulating fireplace in the early 1600s.
The 18th century
1741 – Benjamin Franklin invented a safe, efficient stove.
Benjamin Franklin wanted to improve the efficiency of the fireplace.
He created a metal-lined fireplace known as the ‘Franklin Stove’ that transferred more heat to a room than any previous inventions.
His theory about heat was that it acted like a liquid, in that it wanted to rush out of a room, unless it was contained.
1745 – William Cook first proposed the concept of steam heating.
William Cook was the first to propose steam heating in 1745 in England.
1790 – Steam engine pioneers Matthew Boulton, and James Watt used steam heating in their homes
Boulton and Watt used a central boiler and a system of pipes to develop the first working steam-based heating system for their homes.
The 19th century – The Industrial Revolution
And this is where it all really took off…
1802 – Zachaus Winzler developed the first gas stove
With the Industrial Revolution, came advances in fuel technology and the advent of gas. A major improvement in fuel technology came with the advent of gas. James Sharp patented a gas stove.
1805 – William Strutt invented a warm-air furnace
William Strutt created a furnace with a wrought iron air chamber, surrounded by stone to create both cool and warmed air.
1830 – Andre Ure invented a bimetal thermostat
Ure’s thermostat was based around a strip made of two different metals that would bend when a room reached a certain temperature, triggering a switch to turn the heating system on, or off.
1854 – Stephen Gold created the ‘mattress radiator’
Gold’s radiator was a device made of two dimpled iron sheets that were riveted together at the dimples, making it look like a mattress.
1855 – 1857 Franz San Galli invented the radiator
Prussian inventor Franz San Galli invented a radiator which he patented as the “hot box”.
The hot box was made up of large columns of steel with waterways inside that allowed for hot water to pass through and heat air which in turn heated up the room.
This was a revolution in central heating and was launched in St Petersburg.
1863 – Joseph Nason and Robert Briggs developed the radiator
Nason and Briggs developed a new design of radiator that used vertical wrought iron tubes screwed into a cast iron base. This is a predecessor to the radiator that we know today.
1870 – John Mills invented a successful watertube boiler.
Mills patented his sectional boiler for steam or hot water.
1872 – Nelson Bundy invented the ‘Bundy Loop’
Bundy invented the first popular cast iron radiator that had loops screwed into a cast iron base.
Cast iron sectional radiators were widely used by the 1880s.
1883 – Thomas Edison invented the first electric heater
The earliest electric heaters used bulbs. Thomas Edison patented the lightbulb in 1880.
1885 – Coal surpasses wood as the primary fuel in the developed world and the Bunsen burner is invented
The Bunsen burner was the first time that people were able to regulate a gas flame. This was a precursor to modern gas heating systems.
The 20th century
1906 – Honeywell introduced homeowners to the very first thermostat
William. R. Sweatt designed the first home thermostats that were stamped with “Electric Heat Regulator Co” and were in a semicircle shape. This was later developed into the Honeywell Round thermostat, known simply as The Round.
1919 – Alice Parker patented the first central heating system
Alice Parker was an African American inventor who patented her system of central heating using natural gas.
1923 – Dr. Richard Seligman invented the plate heat exchanger
Seligman found that by using two different metal plates, he could transfer heat from a hot fluid to a cold fluid. This ‘heat-exchanger’ is found in nearly every boiler today.
1930 – Engineers developed fibreglass insulation.
The first fibreglass insulation consisted of extremely fine glass fibres, inside rolls for easy installation.
1937 – The Victorians embraced radiators as aesthetic items as well as functional ones
The Victorians who could afford opulent homes saw radiators as being statement pieces for the home, as well as being functional for heating. Cast iron radiators featured intricate scrolled detail.
1948 – Robert C. Webber invented the direct exchange ground-source heat pump
American inventor Robert C Webber came up with the idea of a ground source heat pump when experimenting with the efficiency of a deep freezer.
1967 – Vaillant invented the first combi-boiler
Vaillant invented the first combi boiler, the ‘Combi-Geyser VCW 20’. For the first time this combined heating and hot water supply in a single unit.
1970’s – electric air-to-air heat pump and solar energy became widely adopted.
The availability of oil and natural gas was problematic in the 1970s. So electric air-to-air heat pumps and solar energy were touted as a solution to the energy crisis.
1980s – Central heating was commonplace
There was an improvement in public health as central heating became commonplace.
The design of homes started changing, with open-plan rooms becoming popular; due to the reduced need to have lots of individual rooms with closed doors to keep the heat in.
The fireplace was no longer the focal point of the room.
The 21st century
2005 – Condensing technology became mandatory on all new boiler installations
Since 2005, all new boilers installed must have condensing technology.
2007 – Stuart Lombard invented the first smart thermostat called the ecobee
Stuart Lombard combined programmable thermostats and WiFi connectivity, making it possible to remotely control your central heating.
2018 – Boiler Plus regulations
The Boiler Plus regulations came about following a public consultation into the future of heat in domestic buildings by the Department for Business, Energy and Industrial Strategy (BEIS) in December 2016.
All boilers must meet this standard for energy efficiency.
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2020 -Boris Johnson’s 10 point plan for a ‘Green Revolution’
In November 2020, Boris Johnson published ‘The Ten Point Plan for a Green Industrial Revolution’. This sets out the government’s priorities for £12bn worth of investment in clean energy; transport; and energy efficiency; to meet the target net zero emissions by 2050.
It means that in the future we’re likely to see a combination of both heat pumps and hydrogen boilers in homes over the coming years to achieve the government’s targets to reduce climate change.
So, what’s clear from this timeline, is that today’s home heating systems have evolved from ideas spanning back decades, and from all around the world.
Thanks to forward-thinking engineers everywhere, we have access to safe heat at our fingertips, and even remotely from our smartphones.
Initially, the challenge was just to develop the technology as part of the Industrial Revolution.
But now we face a new challenge. To continue evolving our technology, but in a more sustainable way.
Over the coming years, we can expect to see the advancement of even greener boilers; heat-pumps; solar; and hydrogen powered heating taking us into the next century.