Heat Pumps

Heat pumps will be the dominant heating technology in the energy system of the future. Scientific studies show that they will play a key role in supplying buildings, industry and district heating with heat and cooling and reducing greenhouse gas emissions.

Heat pumps are used in a wide range of applications. The technical fields of application are the heating of new and existing single-family and multi-family homes as well as non-residential buildings. Large heat pumps can also supply entire cities and neighborhoods with district heating efficiently and reliably. In industry, high-temperature heat pumps with temperatures of up to 200°C are used, for example, to provide process heat. Heat pumps can also be used to make electricity consumption more flexible and stabilize power grids.

Heat pumps are used in the following sections:

• Single Familiy Homes
• Multi Family Homes
• Local and District Heating
• Industry and Commerce

Challenges:

The importance of heat pumps for the energy transition is accompanied by challenges for equipment manufacturers, HVAC contractors, and the housing industry. Methods, components, and products must be developed and established that enable efficient installation and operation. Rapid market growth also requires efficient, cost-effective production methods in order to remain competitive. Further optimizations are needed to simplify the installation of heat pumps in various application scenarios and increase operational efficiency. We are addressing these challenges with our R&D services in the following areas of work.

Further Fields of Work on this Topic:

• Refrigeration Circuits with New Materials and Manufacturing Methods
• Characterization and Testing
• Installation and Operation of Heat Pumps
• Heat Pumps in the Energy System

Heat pumps offer ecological, energetic, and economic advantages that are attractive to end users and important for the energy system of the future. No other heating technology can generate heat with less final energy.

In new single-family homes in Germany, heat pumps have surpassed gas boilers as the most popular heating technology since 2017. They are now used in over 70 percent of new buildings to provide hot water and space heating.

Heat pumps can also achieve good efficiency values in existing buildings, as our analyses show. It makes sense to plan modernization holistically, reduce the building's energy requirements, coordinate the renovation measures, and design the heat pumps optimally for the respective requirements.
 

Advantages:

• Independence from fossil fuels
• Highest efficiency classes in the energy label for heating appliances
• Ability to heat and cool
• Significant reduction in CO2 emissions compared to gas heating systems
• Own consumption of electricity from PV system
• Government subsidies

The requirements for the design of the heat pump and the overall system are more complex in multi-family homes than in single-family homes. In addition to issues of hot water supply and heat transfer systems, the use of environmental energy (heat source) at the location must also be taken into consideration. In residential buildings, geothermal energy or outside air is usually used as the heat source. Where available, waste heat from wastewater is an interesting option. Photovoltaic-thermal collectors (PVT) installed on house roofs serve as both a heat and power source for heat pumps and can be a real alternative, especially in urban areas where space is limited.

Advantages:

• Heat pumps in multi-family homes are more cost-effective in the long term than gas heating systems
• Can be combined with photovoltaics, solar thermal energy, and heating networks
• High proportion of renewable energy through the use of local environmental heat
• Climate neutrality for a very large building sector

In the coming years, heat supply in cities and neighborhoods will increasingly be converted to climate-friendly technologies. Through intelligent solutions, heat pumps can make an important contribution to the modernization and decarbonization of cities, neighborhoods, and heating networks by also utilizing existing infrastructure.

Three types of heating network systems are suitable for the integration of heat pumps in cities and neighborhoods: (1) cold local heating, (2) classic local heating, and (3) district heating. The three variants differ in their fields of application. In the cold local heating concept, heat is generated decentrally and fed into a network that operates at a low temperature level of 8 to 20°C. A classic local heating network is usually built around a single heating center in a neighborhood or residential complex. Large heat pump systems are increasingly taking on this role, replacing or supplementing fossil fuel heat generators. District heating networks are existing systems – efficient large heat pumps can replace gas-powered systems in a climate-neutral way.

Advantages:

• In cold local heating networks, system temperatures can be kept low, so that insulation of the pipes is not necessary.
• Due to the higher system temperature, classic local heating is particularly suitable for converting existing neighborhood networks (existing buildings).
• In district heating systems, heat pumps can be used flexibly, for example to lower the return temperature.

Heat pumps are interesting for industry in various ways. For example, around 20 percent of final energy demand in Germany is used for process heat, a large proportion of which is at temperatures below 150°C. Most of this heat is still generated by burning fossil fuels. In order to achieve a reduction in greenhouse gas emissions in the coming years, a switch to electricity-based heat generation is necessary. Heat pumps can already generate these temperatures with good efficiency and provide stable process heat, even in large output classes.

Heat pumps can also supply non-residential buildings with heat and cooling. In commercial properties, office buildings, hospitals, hotels, or schools, they are used to provide hot water, space heating, and cooling. When used in non-residential buildings, low system temperatures and thus high energy efficiency are possible.

Advantages:

• High efficiency at low system temperatures
• Provision of heating and cooling in one system
• Can be easily connected to photovoltaics, solar thermal energy, and heating networks
• High proportion of renewable energies through the use of local environmental heat

All Research Projects on the Topic "Heat Pumps"