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Heating, cooling and refrigeration systems

Heating, cooling, and refrigeration systems are the major contributors to energy use and CO2 emission worldwide.

Heating, cooling, and refrigeration systems are the major contributors to energy use and CO2 emission worldwide. Taking Europe as an example, heating and cooling contributes to approximately half of the total energy use in the continent. Heating, cooling, and refrigeration systems are among the most influential global players in the field of Energy, Environment, and Human comfort. These systems are widely used for different applications e.g. space heating and air-conditioning in residential and commercial buildings, district heating and cooling, food preservation and many other residential and industrial applications.

Our research focuses on providing sustainable and efficient heating, cooling and refrigeration systems for a large variety of applications. Our research not only covers complex engineering problems from component to system level but also business model innovation, human behavior, and economics. We have a long history of research and innovation on Heat Pump and Supermarket Refrigeration systems and we have supported the Swedish industry over several decades to become one of the pioneers globally in this field. We have a well-equipped laboratory that facilitates experimental analysis of components and systems in a wide range of conditions. Furthermore we have developed holistic system models which can simulate different operation and control strategies for the systems at building and city levels. 

The research conducted in this area cover:

  • Heat Pump and Refrigeration systems (environmentally benign systems, geothermal, Air source, etc.)
  • Combined Solar and Heat Pump systems (Solar PV, Solar thermal, etc.)
  • Low Temperature Power Cycles
  • District Heating/Cooling
  • Smart control and maintenance of heating and cooling systems (System control, Fault Detection and Diagnosis, etc.)


4D Monitoring of BTES (completed)

Alternative secondary fluids for indirect refrigeration systems

The secondary fluid is a complex mixture which also contains pH adjusting agents, antioxidants, anti-foaming agents, stabilizers, colorants, etc. These additives can stabilize and improve the fluid performance but also affects the thermophysical properties. Secondary fluid is water-based solutions of organic or inorganic substances (such as alcohols, glycols and salts) used in various indirect refrigeration systems and heat pumps. The advantages of the indirect refrigeration systems are: low refrigerant charge, low risk of refrigerant leakage, the fact that the primary refrigerant system is localized in the machine room, easy and precise control, no oil recovery problems, refrigerants like ammonia and hydrocarbons can be used; easy maintenance, no technical limitations on the distance between refrigeration and machine room, plastic pipes can be used and that it will be longer intervals between defrost periods when air cooling due to more uniform frost formation.

Building heating solutions in China

Building heating solutions in China: a multi-criteria system analysis based on spatial data

Building state-of-the-art (SotA) supermarket: Putting theory into practice

This project will apply the knowledge accumulated through the research in supermarket energy systems by building a unique demonstration case study is built where today’s most efficient, environmentally friendly and cost-effective supermarket will be designed, installed, monitored, thoroughly evaluated, and well documented.

Capacity control in Heat Pump systems

The overall objective of this project is to develop a structured method to approach the challenge of better understanding the techniques and potential for capacity control in Heat pump systems with a focus on Ground Source Heat Pump (GSHP) systems.

Cooperation between Supermarkets and Real Estate Owners; Energy Efficiency and Business Models

The overall aim of the project is to demonstrate, using theoretical calculations, modelling, energy measurements, monitoring and business model evaluation, that a collaboration for efficient use of heating, cooling and air conditioning between real estate and supermarkets owners can be achievable for both parties.

Data driven lab for building energy systems

A database, which contains operation data from more than 4000 heat pump installations throughout Sweden, can be potentially exploited by end user applications to allow manufacturers, utilities, customers or third parties to perform data monitoring and analysis. However the database suffers from incompleteness, inconsistency, lack of accuracy or sensor calibration issues. To appropriately utilize the database, we will integrate other sources such as models and lab measurements to turn the low quality data into useful information. We will develop a data-driven lab which will act as a virtual platform to improve the control strategies, fault detection and performance degradation.  

Deep Borehole Heat Exchanger (completed)

Digitalization and IoT technologies for Heat Pump systems

In the last decades digital technologies became widely used in energy end-use sectors and digital solutions have been driving dramatic changes in the society. In the years to come, Heat Pumps are expected to turn more and more into connected devices contributing to the Internet of Things (IoT).

Efficient use of energy wells for heat pumps (completed)

Efficient utilization of industrial waste heat by low temperature heat driven power cycles – an integrated approach for Swedish Industry

Industrial waste heat can be efficiently utilized by aid of low temperature heat driven power cycles. The project will provide a use-case approach in a close dialogue with industry and use and refine research findings from previous projects to provide generic insight into typical system sizing issues, working fluid selection and charge minimization of low temperature heat driven power cycles for Swedish industry.

Future Secondary Fluids for indirect refrigeration systems

The F-gas Regulation has set a clear goal for the entire refrigeration industry to reduce the amount of GWP fluorinated greenhouse gases. Natural refrigerants with very low GWP values such as carbon dioxide, propane and ammonia have excellent properties and the only disadvantages are flammability and toxicity in case of ammonia. In order to increase the use of these refrigerants, and to reduce climate impact, it is important to find environmentally friendly and energy efficient secondary fluids for indirect systems with low pumping power and good heat transfer properties.

High-Resolution GIS District Heating Source-Load Mapping

Fossil fuels still account for around 7% of input energy used for the production of district heating (DH) in Sweden. With this study, we will develop a high-resolution Geographical Information System (GIS) platform, which can map the potentials of the renewable and recycled heat sources surrounding cities, and analyse cost efficient modalities of matching the sources and seasonal storages with building heat loads.

Improved borehole technology for Geothermal Heat Pumps development (completed)

The implementation of a larger number of geothermal heat pumps (GHP) with better energy efficiency would help contributing to the 40% reduction of domestic greenhouse gases emissions by 2020, which is one of Sweden’s “miljömål” (2030 for the EU according the INDC). The other goals that this project could contribute fulfilling are “God bebyggd miljö”, “Grundvatten av god kvalitet” and “Frisk luft”.

Long-term performance measurement of GSHP systems serving commercial, institutional and multi-family buildings

Measured long-term performance data for ground source heat pump systems serving commercial, institutional and multi-family buildings are rarely reported in the literature. Energy use intensity figures are occasionally published, but as they necessarily lump the building loads and the system performance together, they are of limited usefulness in understanding real-world system performance.
Annex 52 will bridge the gap between those who see the heat pump system as a complex environment and the ground source as a black box, and those who see the ground source as a complex environment and the heat pump system as a black box.

Magnetic Refrigeration

Although Magnetic refrigeration is a well-known method in cryogenics, it has not been commercially used at room-temperature. In this project, the possibilities with and the potentials of magnetic refrigeration system are investigated to find the most suited application for commercializing the technology.

Novel tool and guidelines for designing ground source heat pumps (GSHPs) in densely populated areas

Ground source heat pumps (GSHPs) are a widespread technology in Sweden and its spread is forecasted to increase even further. However, designers of such systems lack a dedicated design tool when dealing with independent GSHPs, like in densely populated areas. This results in systems operating with lower efficiency than expected.

Performance indicators for energy efficient supermarket buildings

Annex 44: "Performance indicators for energy efficient supermarket buildings" is a European project to define the indicators required to evaluate the energy efficiency in supermarket buildings.

Simulation of temperature distribution in borehole thermal storages supported by fiber optic temperature measurements (completed)

Smart Control Strategies for Heat Pump Systems (completed)

A new perspective for improving the heat pump system performance can be given by the development of enhanced system control strategies able to achieve a considerable increase of the system Seasonal Performance Factor together with a reduction of operation and maintenance costs.

Smart Fault Detection and Diagnosis for Heat Pumps

The present project is the first official research project in Sweden which aims at designing a generic solution for Smart Fault Detection and Diagnosis in heat pump systems.

Smart Solar Hybrid Solutions for Sustainable European Buildings (completed)

Achieving the ambitious national goals in the Swedish building sector are impossible without smart, cost-effective, scalable, and integrated solutions for heating, cooling and electricity. The goal of this project is to advance the development of an integrated heating, cooling and electricity system solution for European buildings using solar PVT technology and ground source heat pumps.

Solar energy and ground source heat pumps for Swedish multi-family housing (completed)

Ground source heat pumps (GSHP) are common in Sweden, but solar energy systems are not. GSHP could offer an ideal platform to integrate solar energy into the building and national energy systems towards meeting climate goals and increasing the share of renewable energy to 100%.

Towards Sustainable (Fossil-free) Heating System in Small Residential Buildings

As a growing technology, the number of installed heat pumps in Europe was increased by 60% between 2014 and 2018, and European Heat Pump Association expects a doubling in the heat pump market by 2024. It is therefore a high priority to further increase the share of renewable sources in the heat pump’s configuration to increase the potential of energy savings and to reduce the greenhouse gas emission. The goal of this project is to study the performance of the PVT-assisted GSHP in new- and retrofitted single-family houses.

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