Heat Pump Technology: A Brief History

Heat pumps are the most cost-effective and efficient heating sources on the market. Environmentally friendly, they can significantly reduce your energy bills and carbon footprint. A great way to heat your property and water, they’re a great way to save money and the planet’s scarce resources.

A heat pump needs only a small amount of electricity to run and doesn’t depend on the burning of fossil fuels to create heat. Pumps are known as a clean energy source as a result. They perform effectively in a moderate climate, such as the UK, providing heat even at the very low temperature of -20°C.

Modern heat pumps rely on comparatively new technology, but the geothermal principle of physics behind them is much older. Heat from the earth’s core is used to generate energy known as geothermal energy. The word “geo” means earth and “thermal” means heat.

Geothermal energy

Geothermal energy is a type of sustainable energy that doesn’t use the earth’s resources in the same way as burning gas or coal. Although we use a small amount of the earth’s heat, it’s minute in comparison with the overall heat that the earth produces. Geothermal power plants have been built, which are clean and have little negative impact on the environment.

The concept was used as far back as Ancient China, in the period 1600 BC to 221 BC, when people used hot springs for bathing. In Ancient Rome, beginning in the 8th century BC, people took this concept a step further, using the hot springs to heat public baths and flooring.

Technology origins

The technology behind the first heat pump was first tested in 1748 by William Cullen, a Scottish physician, agriculturalist and chemist, who was a pioneer of artificial refrigeration. He is commonly noted as being responsible for the scientific principle of the heat pump.

Born in Hamilton in 1710, he opened a GP’s practice in the parish of Shotts in 1732. He became interested in chemistry and became a lecturer. In 1756, he gave the first documented public demonstration of refrigeration at Edinburgh University, using a pump to create a partial vacuum in a jar of diethyl ether.

He boiled the ether and the reaction absorbed heat from its surroundings. The process wasn’t practical or commercially viable at this stage, but it was viewed as the starting point for all other experiments and inventions using the same principle.

First heat pump

Between 1855 and 1857, Austrian scientist Peter von Rittinger created the first heat pump system. He began to understand the principle of the heat pump during his experiments using water vapour’s latent heat to evaporate salt brine. This led to the heat pump being used to dry salt in Austria’s salt marshes.

Geothermal energy was first used for electricity in 1904 – the year the geothermal electric generator was invented. In 1911, the first geothermal electric plant was constructed. In the 1940s, the heat pump was first used for heating buildings.

Pioneering invention

American inventor Robert C Webber came up with the idea of a ground source heat pump in 1948. He was experimenting with the efficiency of his deep freezer in the cellar of his home when he accidentally burned his hands on the cooling system’s outlet pipes. He went on to experiment into reversing the mechanics.

He connected the outlet pipe from the freezer to a hot water heater. The freezer produced constant excess heat, so he fastened the heated water to a piping loop. A small fan propelled the warm air into the building. He realised he had come up with a successful invention and went on to further perfect it.

He built a much larger heat pump, providing heating for his home. He designed a system using copper tubing buried in the ground, with Freon gas running through it to collect the ground heat. He condensed the gas in his cellar, it gave off heat and pushed the expanded gas through the ground coil, where it picked up its next load.

He was able to replace the coal furnace in his home, thanks to the successful design of his heat pump. Today, the same design is still used for heat pumps in most HVAC units. The same principle remains in use, although 21st century systems are smaller and more efficient, as technology continues to advance.

Sustainable heating

Webber was the man who inspired a new generation of electrical technology, based on the principle of air conditioning. Heat pumps are now incorporated into many modern new builds on a regular basis.

Klima-Therm produces a range of high-quality heat pumps, including polyvalent and modular systems. Please contact us on 020 8971 4195 or email sales@klima-therm.co.uk for information.