scholarly journals Measured performance of exhaust air heat pumps in Finnish apartment buildings

2021 ◽  
Vol 246 ◽  
pp. 06001
Author(s):  
Petri Pylsy ◽  
Jarek Kurnitski
Keyword(s):  
Heat Pump ◽  
Ventilation System ◽  
Measurement Data ◽  
District Heating ◽  
Energy Performance ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Apartment Buildings

The energy efficiency of existing apartment buildings is playing an important role in energy and climate targets. In Finland, mechanical exhaust ventilation system is commonly used in older apartment buildings. Hence, there could be an energy saving potential by an exhaust air heat pump system (EAHP). In this work two cases have been studied. Buildings were built in 1960’s and 1970’s and in renovation equipped with hybrid heating system: district heating and exhaust air heat pump system. Two years measurement data, 2018 and 2019, was collected to evaluate the performance of exhaust air heat pump systems. According to measurement data the monthly coefficient of performance (COP) was calculated as well as seasonal coefficient of performance (SCOP) was defined. The monthly COP values varied from 3,1 to 4,6 and SCOP values were about 3,7. Heating energy cost savings were 23-31 %. Energy performance class before and after EAHP installation was calculated. If at least 50 % of heating energy consumption was covered by EAHP then also energy performance class was improved.

Photovoltaic thermal collector assisted heat pumps using environment-friendly working fluids

2020 ◽  
pp. 095440892094736
Author(s):  
AA Ammar ◽  
K Sopian ◽  
M Mohanraj
Keyword(s):  
Heat Pump ◽  
Energy Performance ◽  
Heat Pumps ◽  
Payback Period ◽  
Photovoltaic System ◽  
Coefficient Of Performance ◽  
Photovoltaic Module ◽  
Pump System ◽  
Heat Pump System ◽  
Thermal Evaporator

In this research, a photovoltaic-thermal collector assisted heat pump has been developed and tested its performance under the tropical climatic conditions of Malaysia. The refrigerants such as, R134a and R1234yf were selected based on its thermodynamic and thermo-physical properties. The temperature of the photovoltaic module was theoretically predicted under the influence of tube diameter, tube spacing and refrigerant mass flow rate. Further, the energy performance of the photovoltaic-thermal evaporator and the heat pump system are investigated experimentally. Finally, the economical feasibility of the photovoltaic-thermal collector evaporator was assessed for the period of 20 years. The results showed that, the tube spacing and diameter of the copper tubes used in the photovoltaic-thermal evaporator/collector using R134a and R1234yf were optimized to 80 mm and 12.7 mm, respectively. It was observed that, during the clear sunny day, the average photovoltaic module temperature was reduced to 30.9 °C under the influence of panel cooling using refrigerant. The output of the panel was enhanced by 21%–44% with increase in solar radiation from 400 W/m2 to 1000 W/m2. The coefficient of performance of the heat pump was varied from 4.8 to 6.84 with an average coefficient of performance of 5.8 during clear sunny days. The life cycle economic analysis indicated that, the photovoltaic-thermal collector evaporator assisted heat pump has a payback period of 3 years, whereas the reference photovoltaic system has a payback period of 8 years.

scholarly journals Optimization of emission reducing energy retrofits in Finnish apartment buildings

2019 ◽  
Vol 111 ◽  
pp. 03002 ◽  
Author(s):  
Janne Hirvonen ◽  
Juha Jokisalo ◽  
Juhani Heljo ◽  
Risto Kosonen
Keyword(s):  
Heat Pump ◽  
Life Cycle Cost ◽  
District Heating ◽  
Cost Savings ◽  
Cost Effective ◽  
Energy Performance ◽  
Heat Pumps ◽  
Apartment Buildings ◽  
Ground Source ◽  
Reduce Emissions

This study examined the cost-optimality of energy renovation on Finnish apartment buildings of different ages, built according to different energy performance requirements. Multi-objective optimization was utilized to minimize both CO2 emissions and life cycle cost (LCC). IDA-ICE simulations were performed to obtain the hourly heating demand of the buildings. Four building age classes and three heating systems (district heating, exhaust air heat pump and ground-source heat pump) were separately optimized. With district heating, it was possible to reduce emissions by 11%, while also reducing LCC. With heat pumps cost-savings could be achieved while reducing emissions by over 49%. With maximal (not cost-effective) investments, emissions could be reduced by more than 70% in all examined cases. In all cases, the cheapest solutions included solar electricity and sewage heat recovery. In old buildings, window upgrades and additional roof insulation were cost-effective. In new buildings, demand-based ventilation was included in all optimal solutions.

scholarly journals Digital technological model of heat exchange control in an air heat pump in a low-rise building

2021 ◽  
Vol 2131 (5) ◽  
pp. 052080
Author(s):  
S V Fedosov ◽  
V N Fedoseev ◽  
V A Emelin ◽  
S A Loginova
Keyword(s):  
Heat Pump ◽  
Heat Supply ◽  
Ventilation System ◽  
Heat Supply System ◽  
Heat Pumps ◽  
Joint Work ◽  
Pump System ◽  
Heat Pump System ◽  
Energy Devices ◽  
Mixing Chamber

Abstract The use of air source heat pumps together with other renewable energy devices and highly efficient heating equipment together with digital control systems is a promising European trend that continues to grow in the face of rising prices for traditional energy sources. The article presents a number of technical energy-saving solutions, such as a mixing chamber for HVH, built into the heat supply system and the use of a supply and exhaust ventilation system, in which the principle of recuperation is incorporated. A digital modular-functional-structural diagram of heat generation of a heat carrier from the environment is proposed. Relying on the energy efficiency of the circuit design with an electric boiler, a buffer tank and a patented mixing chamber, the authors achieve a rationally controlled heat and air exchange of a combined heat pump system for heating premises. Automation of the joint work of rationally selected elements of the heat pump air system is one of the Smart Home technologies that improve the efficiency of heat supply, create comfortable living conditions and safety through digitalization of the control algorithm for this system.

scholarly journals Implementation of a geothermal heat pump system in a solar passive house

2019 ◽  
Vol 85 ◽  
pp. 07014
Author(s):  
Gheorghe Ilisei ◽  
Tiberiu Catalina ◽  
Marian Alexandru ◽  
Robert Gavriliuc
Keyword(s):  
Heat Pump ◽  
Electricity Consumption ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Passive House ◽  
Geothermal Heat ◽  
Pump System ◽  
Heat Pump System ◽  
Major Index ◽  
Passive Houses

Underground energy sources are becoming increasingly popular and now geothermal heat pumps are frequently used to heat/cool different types of buildings, including for solar passive houses. This article aims at giving a contribution in the development of the thermal modelling of borehole heat storage systems, investigating the possibility of a GSHP (ground source heat pump) implementation with vertical boreholes in a solar passive house. A case study analysing a residential solar passive house is presented as a suitable modelling tool for the estimation of the thermal behaviour of GSHP systems by combining the outcome from different modelling programs. The software DesignBuilder, Earth Energy Designer and a sizing method for borehole’s length are used for producing the numerical results. The results highlight that the length of the borehole, a major index in estimating the system’s cost, is directly influenced by fundamental variables like thermal conductivity of grout or soil. Additionally, correlations between these parameters and the coefficient of performance of GSHP were made. Furthermore, the length of borehole is very important as it is responsible for almost half of the total installation cost and triggered a difference in electricity consumption of the GSHP up to 14%.

Energy Analysis and Optimization of a Water-Loop Heat Pump System

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Shui Yuan ◽  
Michel Grabon
Keyword(s):  
Water Temperature ◽  
Heat Pump ◽  
Energy Savings ◽  
Water Source ◽  
Energy Performance ◽  
Heat Pumps ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling ◽  
The Impact

A water-loop heat pump system consists of a set of water-source heat pumps that are connected with a closed-loop water network, which allows heat to be injected into or extracted out of the loop water. Such a configuration is able to meet simultaneous heating and cooling demands with a heat recovery capability. This paper analyzes the impact of loop water temperature on energy performance of individual heat pumps and the whole system, demonstrates that there exists a unique loop water temperature that minimizes overall power consumption of the configuration under discussion, and proposes a strategy to find the optimal temperature, which can be implemented in a real-time application. Simulations have been conducted to verify that a significant energy savings can be achieved over conventional practice.

scholarly journals Enhancing Heating Performance of Low-Temperature Air Source Heat Pumps Using Compressor Casing Thermal Storage

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3269 ◽  
Author(s):  
Zhongbao Liu ◽  
Fengfei Lou ◽  
Xin Qi ◽  
Yiyao Shen
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Waste Heat ◽  
Thermal Storage ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Discharge Temperature ◽  
Vapor Injection

Air source heat pumps (ASHPs) are widely recognized as energy-saving and environmentally friendly heating and air-conditioning equipment with broad applications. However, when conventional ASHPs are operated at a low ambient temperature, they suffer from problems such as high discharge temperature and low heating efficiency. To address these problems, this study designed a new type of dual evaporator combined with a compressor casing thermal storage heat pump system (DE-CCTS) on the basis of a low-temperature air source heat pump water heater with enhanced vapor injection (EVI). The proposed DE-CCTS used thermal storage phase change material (PCM), which was filled in the secondary evaporator (the thermal storage heat exchanger), to recover the waste heat of the compressor casing. Unlike that in the original system under different ambient temperatures, the suction temperature increased by 0.1–1 °C, the discharge temperature decreased by 0.1–0.5 °C, and the coefficient of performance (COP) of DE-CCTS increased by 0.85–4.72% under the proposed system. These effects were especially evident at low temperatures.

scholarly journals Performance evaluation of heat pump system using R744/R161 mixture refrigerant

2014 ◽  
Vol 18 (5) ◽  
pp. 1673-1677
Author(s):  
Xian-Ping Zhang ◽  
Xin-Li Wei ◽  
Xiao-Wei Fan ◽  
Fu-Jun Ju ◽  
Lei Yang
Keyword(s):  
Heat Pump ◽  
Mass Fraction ◽  
Variable Mass ◽  
Heat Pumps ◽  
Montreal Protocol ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Conservation Technology ◽  
Phase Out

As an efficient and energy conservation technology, heat pumps working with R22, which are scheduled to be phased out by Montreal Protocol, are widely used in China at present. The global deteriorating ecology environment would accelerate the phase-out time of R22 in developing countries. Therefore, as a matter of urgency, an eco-friendly substitute should be investigated in order to replace R22. Under this context, and with a consideration of the environmental protection, R744/R161 mixture refrigerant is proposed. R744/R161 mixture refrigerant?s condensation pressure is reduced and its flammability and explosivity are suppressed. A thermodynamic model is developed, and under the given working conditions, the performances of subcritical heat pump system using R744/R161 mixture of variable mass fraction are discussed and compared with those of the R22 system. The optimal mass fraction of R744/R161 is given, which corresponds to a maximal heating coefficient of performance. The simulation results show that R744/R161 mixture can work as a competitive alternative to R22 in heat pump system.

scholarly journals Life cycle cost analysis of different residential heat pump systems

2020 ◽  
Vol 207 ◽  
pp. 01014
Author(s):  
Nadezhda Doseva ◽  
Daniela Chakyrova
Keyword(s):  
Energy Efficiency ◽  
Life Cycle ◽  
Heat Pump ◽  
Life Cycle Cost ◽  
Residential Buildings ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling

Nowadays, the application of air-source heat pumps for heating and cooling in residential buildings has been increased significantly. The main occasion for this is the accessibility of a heat source for these devices - the external air. Nevertheless, the increase of the energy efficiency of the air source heat pump systems is a difficult design problem because their capacity and performance are a function of the dynamically changing parameters of the outdoor air. Because of that, the main aim of this study is to develop an approach for choosing a structural scheme of an air-to-water heat pump system under specific climatic conditions. The considered systems are monovalent, bivalent-parallel and bivalent-alternative heat pump systems. In the current paper is conducted a dynamic energy modeling of heating and cooling demand of a typical residential building situated in Varna, Bulgaria and applying the bin temperature data. It is assessed the effect of the heat pump capacity over the annual and seasonal energy performance of the heat pump systems. It is established the effect of the bivalent temperature, cut-off temperature and on-off cycles duration on rates of the criteria for techno-economic assessment. The seasonal coefficient of performance (SCOP), seasonal energy efficiency rate (SEER) and life cycle costs (LCC) of the analyzed heat pump systems are adopted as assessment parameters.

TECHNOLOGY REVIEW OF TWO-STAGE VAPOR COMPRESSION HEAT PUMP SYSTEM

2013 ◽  
Vol 21 (03) ◽  
pp. 1330002 ◽  
Author(s):  
KOJO ATTA AIKINS ◽  
SANG-HYEOK LEE ◽  
JONG MIN CHOI
Keyword(s):  
Heat Pump ◽  
High Efficiency ◽  
Industrial Applications ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Two Stage ◽  
Pump System ◽  
Heat Pump System ◽  
Discharge Temperature ◽  
Increasing Demand

There is increasing demand for domestic and industrial refrigeration, space heating and air conditioning. Heat pump systems offer economical alternatives for recovering heat from different sources for use in these applications. As a renewable energy technology for sustainable environment, the heat pump's high efficiency and low environmental impact have already drawn a fair amount of attention all over the world. Some of these domestic and industrial applications require very low evaporating temperatures and very high condensing temperatures which induce high compressor pressure ratios beyond the practical range for single-stage heat pump cycles. These high pressure ratios also produce low coefficient of performance (COP) values and expose the compressor to high discharge temperature, low volumetric efficiency and damage. However, this challenge can be overcome by adopting two-stage heat pump cycles. In this paper, recent works on two-stage heat pump systems for various applications are reviewed. They include two-stage cycle with intercooling, two-stage cycle with refrigerant injection and two-stage cascade cycle. Research and innovative designs of systems that make use of these two-stage cycles have been able to get heat pumps to handle applications with lower and higher temperatures, while enhancing heating capacity up to 30% and COP up to 31%.

Evaluation of the Performance of a Ground-Water Heat Pump System in Hot-Summer and Cold-Winter Region

2013 ◽  
Vol 805-806 ◽  
pp. 616-619
Author(s):  
Fei Lei ◽  
Ping Fang Hu
Keyword(s):  
Ground Water ◽  
Heat Pump ◽  
Energy Savings ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Air Conditioner ◽  
Central System ◽  
Pump System ◽  
Heat Pump System ◽  
Savings Rate

This study presented the energy performance evaluation of a ground-water heat pump (GWHP) system based on actual operational data. The GWHP system was installed for apartment buildings in Wuhan, China. During one year, various operating parameters of the GWHP system were monitored and the coefficient of performance (COP) of system was determined based on the measurement. The energy consumption of the GWHP system is more than twice the average value of split air conditioner on residential application, because of continuously operating of the GWHP system and frugally intermittence operating of split air conditioner. The GWHP system is more economical than other central system. The energy savings rate of the GWHP system was 41.5% for the heating season comparing with boiler and 42% for the cooling season comparing with air source heat pump.

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