Solar-Assisted Heat Pump Systems: A Review of Existing Studies and Their Applicability to the Canadian Residential Sector

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Jenny Chu ◽  
Cynthia A. Cruickshank

Combining solar thermal collectors and heat pumps into a single solar-assisted heat pump (SAHP) system is a promising technology for offsetting domestic hot water (DHW), space-heating, and cooling loads more efficiently. Task 44 of the Solar Heating and Cooling (SHC) Programme of the International Energy Agency (IEA) is currently investigating ways to optimize solar and heat pump systems for residential use. This paper presents a review of past and current work conducted on SAHP systems. Specifically, the key performance data from many studies are highlighted and different system configurations are compared in order to establish insight toward which system configurations are suitable for the Canadian residential sector. It was found that the most suitable configuration for Canadian residential buildings depends on a combination of factors which include occupant behavior, building characteristics, operation parameters, system components, and climate. A large variety of configurations and parameters exist and this made analyzing a specific system, comparing differing systems and establishing an optimal design difficult. It was found that different authors used different performance criterion and this inconsistency also added to the difficulty of comparing the studies of different systems.

Author(s):  
Jenny Chu ◽  
Cynthia A. Cruickshank

Heat pumps are commonly used for space-heating and cooling requirements. The combination of solar thermal and heat pump systems as a single solar-assisted heat pump (SAHP) system is a promising technology for offsetting domestic hot water, space-heating and cooling loads more efficiently. Task 44 of the Solar Heating and Cooling Programme of the International Energy Agency is currently investigating ways to optimize SAHP systems for residential use. This paper presents a review of past and current work conducted on SAHP systems. Specifically, the key performance data from many studies are highlighted and different system configurations are compared in order to establish insight towards which system configurations are suitable for the Canadian residential sector. It was found that the most suitable configuration for Canadian residential buildings depend on a combination of factors which may include occupant behavior, building characteristics, operation parameters, system components, the performance criteria of interest and climate. A large variety of configurations and parameters exist for SAHP systems and this made analyzing a specific system, comparing differing systems and establishing an optimal design fairly difficult. It was found that different authors used various different performance criterions and this inconsistency also added to the difficulty of comparing the studies of different systems. Overall, a standard performance criterion needs to be established for SAHP systems in order to meaningfully compare different configurations and determine optimal configurations for certain requirements.


Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2496 ◽  
Author(s):  
Laura Carnieletto ◽  
Borja Badenes ◽  
Marco Belliardi ◽  
Adriana Bernardi ◽  
Samantha Graci ◽  
...  

The design of ground source heat pumps is a fundamental step to ensure the high energy efficiency of heat pump systems throughout their operating years. To enhance the diffusion of ground source heat pump systems, two different tools are developed in the H2020 research project named, “Cheap GSHPs”: A design tool and a decision support system. In both cases, the energy demand of the buildings may not be calculated by the user. The main input data, to evaluate the size of the borehole heat exchangers, is the building energy demand. This paper presents a methodology to correlate energy demand, building typologies, and climatic conditions for different types of residential buildings. Rather than envelope properties, three insulation levels have been considered in different climatic conditions to set up a database of energy profiles. Analyzing European climatic test reference years, 23 locations have been considered. For each location, the overall energy and the mean hourly monthly energy profiles for heating and cooling have been calculated. Pre-calculated profiles are needed to size generation systems and, in particular, ground source heat pumps. For this reason, correlations based on the degree days for heating and cooling demand have been found in order to generalize the results for different buildings. These correlations depend on the Köppen–Geiger climate scale.


2007 ◽  
Vol 129 (4) ◽  
pp. 438-448 ◽  
Author(s):  
E. Andersen ◽  
S. Furbo

A theoretical analysis of differently designed solar combi systems is performed with weather data from the Danish Design Reference Year (55 deg N). Three solar combi system designs found on the market are investigated. The investigation focuses on the influence of stratification on the thermal performance under different operation conditions with different domestic hot water and space heating demands. The solar combi systems are initially equipped with heat exchanger spirals and direct inlets to the tank. A step-by-step investigation is performed demonstrating the influence on the thermal performance of using inlet stratification pipes at the different inlets. Also, how the design of the space heating system, the control system of the solar collectors, and the system size influence the thermal performance of solar combi systems are investigated. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32.


Author(s):  
Wessam El-Baz ◽  
Peter Tzscheutschler ◽  
Ulrich Wagner

There is a continuous growth of heat pump installations in residential buildings in Germany. The heat pumps were not only used for space heating and domestic hot water consumption but also to offer flexibility to the grid. the high coefficient of performance and the low cost of heat storages made the heat pumps an optimal candidate for the power to heat applications. Thus, several questions are raised about the optimal integration and control of the heat pump system with buffer storages to maximize its operation efficiency and minimize the operation costs. In this paper, an experimental investigation is performed to study the performance of a ground source heat pump (GSHP) with a combi-storage under several configurations and control factors. The experiments were performed on an innovative modular testbed that is capable of emulating a ground source to provide the heat pump with different temperature levels at different times of the day. Moreover, it can emulate the different building loads such as the space heating load and the domestic hot water consumption in real-time. The data gathered from the testbed and different experimental studies were used to develop a simulation model based on Modelica that can accurately simulate the dynamics of a GSHP in a building. The model was validated based on different metrics. Energetically, the difference between the developed model and the measured values was only 3.08\% and 4.18\% for the heat generation and electricity consumption, respectively.


Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4589 ◽  
Author(s):  
Amoabeng ◽  
Lee ◽  
Choi

The energy consumption for heating and cooling in the building sector accounts for more than one-third of total energy used worldwide. In view of that, it is important to develop energy efficient cooling and heating systems in order to conserve energy in buildings as well as reduce greenhouse gas emissions. In both commercial and residential buildings, the heat pump has been adopted as an energy efficient technology for space heating and cooling purposes as compared to conventional air conditioning systems. However, heat pumps undergo standard testing, rating, and certification procedures to ascertain their system performance. Essentially, the calorimeter for testing heat pumps has two test chambers to serve as a heat source and heat sink to control and maintain the test conditions required to simulate the heat pump indoor and outdoor units, simultaneously. In air-to-air heat pump units, the conventional calorimeter controls the air temperature and humidity conditions in each test chamber with separate air handling units consisting of a refrigerator, heater, humidifier, and supply fan, which results in high energy consumption. In this study, using dynamic modeling and simulation, a new calorimeter for controlling air conditions in each test chamber is proposed. The performance analysis based on simulation results showed that the newly proposed calorimeter predicted at least 43% energy savings with the use of a heat recovery unit and small refrigerator capacity as compared to the conventional calorimeter that utilized a large refrigerator capacity for all the weather conditions and load capacities that we investigated.


HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1576
Author(s):  
Piotr Jadwiszczak ◽  
Jakub Jurasz ◽  
Bartosz Kaźmierczak ◽  
Elżbieta Niemierka ◽  
Wandong Zheng

Heating and cooling sectors contribute to approximately 50% of energy consumption in the European Union. Considering the fact that heating is mostly based on fossil fuels, it is then evident that its decarbonization is one of the crucial tasks for achieving climate change prevention goals. At the same time, electricity sectors across the globe are undergoing a rapid transformation in order to accommodate the growing capacities of non-dispatchable solar and wind generators. One of the proposed solutions to achieve heating sector decarbonization and non-dispatchable generators power system integration is sector coupling, where heat pumps are perceived as a perfect fit. Air source heat pumps enable a rapid improvement in local air quality by replacing conventional heating sources, but at the same time, they put additional stress on the power system. The emissions associated with heat pump operation are a combination of power system energy mix, weather conditions and heat pump technology. Taking the above into consideration, this paper presents an approach to estimate which of the mentioned factors has the highest impact on heat pump emissions. Due to low air quality during the heating season, undergoing a power system transformation (with a relatively low share of renewables) in a case study located in Poland is considered. The results of the conducted analysis revealed that for a scenario where an air-to-water (A/W) heat pump is supposed to cover space and domestic hot water load, its CO2 emissions are shaped by country-specific energy mix (55.2%), heat pump technology (coefficient of performance) (33.9%) and, to a lesser extent, by changing climate (10.9%). The outcome of this paper can be used by policy makers in designing decarbonization strategies and funding distribution.


Author(s):  
Mohammad Omar Temori ◽  
František Vranay

In this work, a mini review of heat pumps is presented. The work is intended to introduce a technology that can be used to income energy from the natural environment and thus reduce electricity consumption for heating and cooling. A heat pump is a mechanical device that transfers heat from one environmental compartment to another, typically against a temperature gradient (i.e. from cool to hot). In order to do this, an energy input is required: this may be mechanical, electrical or thermal energy. In most modern heat pumps, electrical energy powers a compressor, which drives a compression - expansion cycle of refrigerant fluid between two heat exchanges: a cold evaporator and a warm condenser. The efficiency or coefficient of performance (COP), of a heat pump is defined as the thermal output divided by the primary energy (electricity) input. The COP decreases as the temperature difference between the cool heat source and the warm heat sink increases. An efficient ground source heat pump (GSHP) may achieve a COP of around 4. Heat pumps are ideal for exploiting low-temperature environmental heat sources: the air, surface waters or the ground. They can deliver significant environmental (CO2) and cost savings.


Author(s):  
Z. Sirkо ◽  
◽  
V. Korenda ◽  
I. Vyshnyakov ◽  
O. Protasov ◽  
...  

Heat pump - a device for transferring thermal energy from a source of low potential thermal energy to a consumer with a higher temperature. The thermodynamic cycle of a heat pump is similar to a refrigerating machine. Depending on the principle of operation, heat pumps are divided into compression and absorption. The most commonly used compression heat pumps. In recent years, numerous publications on the use of heat pump technology in heating and hot water supply facilities of various spheres - from individual homes to residential neighborhoods have appeared in various media. The authors of the publication have many years of experience in joint scientific and technical cooperation with leading technical universities and industrial organizations in the field of development and practical use of heat pump technology. The authors analyze the possibilities of introducing heat pumps at enterprises and organizations of the State Reserve System of Ukraine. It has been shown that the amount of expenses in comparison with central heating or operation of gas and electric boilers of similar power is several times smaller. It is noted that the implementation of heat pumps is a promising direction in the use of alternative energy sources to meet the heating, ventilation and hot water supply needs of buildings. The payback period from the introduction of heat pumps at enterprises is 4-9 years, depending on the location of the object and the type of source of low-temperature heat. The article meets the requirements of the State Tax Code of Ukraine and can be recommended for publication.


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