02/04/2014 - 13:22
Renewable Energy Development Institute - REDI
fridges with heat pumps

The history of heat pump development is inextricably connected with the history of refrigerator development. In 1852 William Thomson (the lord Kelvin) proposed a practical system of heat pumps which called “the heat multiplier”. Then the system of heat pumps was improved and elaborated, especially by an engineer from Austria- Piotr Ritter von Rittinger, which should be considered as the creator of the heat pump. It is just him who designed the first heat pumps in 1885. However, it was used in practice much more later, in the forties of the XX century with the help of the inventor Robert Weber. The patent on the heat pumps technology was given in 1912 in Switzerland. They developed in the thirties of the XX century when the first heat pump designed for heating and providing domestic hot water, which used the heat from the ambient air, was built in England. In 1990, the USA launched the first heat pump that was installed in the building of lighting combined headquarters in New Haven, Connecticut.

The heat pump is a device which transforms heat from a low-temperature source to a higher temperature environment such as the house heating system. What distinguishes the heat pump’s heat from other sources, it is possibility to use a low potential energy taken from the environment (earth, air, and water) to cover the needs of the heat during the heating season, to heat water for providing domestic hot water and cooling the house in summer. Therefore, the heat pump provides highly effective energy supplies without the use of gas and other hydrocarbons.

The heat pump is able to draw heat from a number of sources such as air, water or earth. Depending on the kind of heat and its receiver, an evaporator and a capacitor can be fulfilled as a heat exchanger “air-liquids”, “air-air” or “liquid-liquid”. The advantages of the system of heat pumps “air-air over the pumps “air-liquid” are a lower cost and a low temperature of runoff (the temperature of the air mass passing through the capacitor heat exchanger). This allows to provide better performance so a high level of heat emission.

A few decades ago the heat pumps were really expensive and available only to a wealthy social class, but with the development of technology they have became more accessible to many people. Nowadays the heat pumps as well as solar collectors are used to warm surfaces and to supply domestic hot water.

Due to changes in policies of many countries which aim is to rescue the ecological situation on the Earth, most countries have begun to use organic fuels. In this way the heat pumps have become one of the alternative types of heating system. They are ecologically clean devices because the operation does not emit the products of combustion and they do not produce waste products.

The use of heat pumps bodes well for the future of the combined systems, in conjunction with other technologies using renewable energy sources such as solar and wind energy, and bio-energy, which allows to achieve the highest economic indicators. The use of heat pumps is the largest contributor to the economy of non-renewable energy resources with the help of non-traditional energy technologies.

Heat pumps due to their energy efficiency conquered the markets of the USA, China, Japan and EU countries long time ago. Increasingly, they are used in heating systems. Such systems are very popular, so people do not just obtain a regular supply of hot water, but also heated floors in their homes.

At present, the world is running about 10 million heat pumps of various powers – from a few kW to hundreds of MW. According to estimates of the World Energy Committee until 2020 in developed countries the share of heating and hot water supply by heat will not be less than 75%. This proves that the global policy is changing its strategy for the heat supply: there is a transition from the traditional burning of organic fuel to use efficient energy technologies for the processing of ambient heat or technical heat escape.

Every year in the USA million heat pumps are produced. While constructing new buildings the heat pumps are used to its heating. This standard was approved by federal U.S legislation.

In Germany the state subsidy is provided for the installation of geothermal heat pumps in the amount of 200 euro for each kW of power set. In Sweden, the heat pumps provide 50% of the total heat. However, in Stockholm, geothermal heat pumps provide 12% of the total heat of the city of power set of 320 MW.

Based on the rate of using heat pumps it may be assumed that in the near future they will be installed in each house. This will be as obvious as presence of the refrigerator in each house today.


People are forever trying to find new sources of renewable energy, so it isn’t surprising that they are especially interested in water and its versatility. Accordingly, much effort has been directed into obtaining energy from tidal and wave power, which are defined as circular movements of water molecules caused by wind that moves water surface through friction.