Heat pumps are a proven technology today that is efficient for heating buildings and generating domestic hot water. They require relatively low investments, are easy to install and are very reliable in their operation. As a result, the use of heat pumps in buildings has grown rapidly over the recent decades.
In Switzerland, for instance, the market share of newly built single and multi-family houses with heat pumps has reached over 80% in recent years. In addition, heat pump technology for specific heating and cooling applications is widely used in the industrial and service sector, trade and commerce, households, mobility, etc.
The potential for heat pumps has not been fully exploited. On the one hand, an important foundation for expanding the use of common heat pump systems lies in the substantial increase in their efficiency. On the other hand, heat pumps are moving into many new applications and markets.
Particularly interesting are heating requirements, at temperature levels suitable for heat pumps, for which electric resistance heaters are typically used. A good example of this is the water heating required in various household appliances. Although applying a heat pump for these types of processes is not very efficient, considerable amounts of electrical energy can be saved relative to the traditional electrical heater approach.
In household appliances, such as refrigerators or dryers, the use of heat pumps is the standard. In other appliances, such as dishwashers and washing machines, resistance type heaters are still used requiring a large amount of electrical energy.
If the water is heated by means of an integrated heat pump, the demand for electrical energy can be halved compared to today's commercially available standard appliances. In recent years, such devices have been developed and are available on the market.
Another interesting new application is the use of heat pumps for heating electrically powered cars (e-cars) or for the thermal management of electrically powered trucks (e-trucks). Many e-cars are presently electrically heated, which reduces their range in winter by up to 50 %. The efficiency, and thus the range, of e-cars can be significantly increased by heating with a heat pump.
In e-trucks, the heat pump can provide the entire thermal management such as heating and cooling of the passenger compartment, battery and power electronics and unit The examples above show that heat pumps in new and special applications offer the economy great opportunities for innovative products and systems enabling more energy efficiency and profitability.
In doing so, R&D has to solve many new and challenging questions, whether it be the design of new heat exchangers, compressors and other components, or the development of heat pumps, or optimal control systems.
Heat pumps do a lot - but they can do even more. The use of heat pumps in new applications will become standard, helping to save energy and reduce C02 emissions. In this issue, several interesting examples of new and special applications are presented. Enjoy the articles.
PROF. DR. BEAT WELLIG
LUCERNE UNIVERSITY OF APPLIED SCIENCES AND ARTS - SCHOOL FOR ENGINEERING AND ARCHITECTURE - SWITZERLAND