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 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.

scholarly journals Heat pump systems: A mini review

2021 ◽  
Vol 4 (2) ◽  
pp. 73-81
Author(s):  
Mohammad Omar Temori ◽  
František Vranay
Keyword(s):  
Heat Pump ◽  
Electricity Consumption ◽  
Cost Savings ◽  
Electrical Energy ◽  
Primary Energy ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Heating And Cooling ◽  
Ground Source ◽  
Reduce Electricity Consumption

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.

scholarly journals Ground-Source Heat Pumps with Horizontal Heat Exchangers for Space Cooling in the Hot Tropical Climate of Thailand

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1274 ◽  
Author(s):  
Arif Widiatmojo ◽  
Sasimook Chokchai ◽  
Isao Takashima ◽  
Yohei Uchida ◽  
Kasumi Yasukawa ◽  
...  
Keyword(s):  
Economic Growth ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Life Cycle Cost ◽  
Heat Pumps ◽  
Ground Source Heat Pump ◽  
Ground Source Heat Pumps ◽  
Air Source Heat Pump ◽  
Ground Source ◽  
Space Cooling

The cooling of spaces in tropical regions, such as Southeast Asia, consumes a lot of energy. Additionally, rapid population and economic growth are resulting in an increasing demand for space cooling. The ground-source heat pump has been proven a reliable, cost-effective, safe, and environmentally-friendly alternative for cooling and heating spaces in various countries. In tropical countries, the presumption that the ground-source heat pump may not provide better thermal performance than the normal air-source heat pump arises because the difference between ground and atmospheric temperatures is essentially low. This paper reports the potential use of a ground-source heat pump with horizontal heat exchangers in a tropical country—Thailand. Daily operational data of two ground-source heat pumps and an air-source heat pump during a two-month operation are analyzed and compared. Life cycle cost analysis and CO2 emission estimation are adopted to evaluate the economic value of ground-source heat pump investment and potential CO2 reduction through the use of ground-source heat pumps, in comparison with the case for air-source heat pumps. It was found that the ground-source heat pumps consume 17.1% and 18.4% less electricity than the air-source heat pump during this period. Local production of heat pumps and heat exchangers, as well as rapid regional economic growth, can be positive factors for future ground-source heat pump application, not only in Thailand but also southeast Asian countries.

scholarly journals Towards the EU Emission Targets of 2050: Cost-Effective Emission Reduction in Finnish Detached Houses

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4395 ◽  
Author(s):  
Janne Hirvonen ◽  
Juha Jokisalo ◽  
Juhani Heljo ◽  
Risto Kosonen
Keyword(s):  
Life Cycle Cost ◽  
Cost Effective ◽  
Heat Pumps ◽  
Building Envelope ◽  
The European Union ◽  
Building Stock ◽  
Ground Source Heat Pumps ◽  
Emission Reductions ◽  
Heating Systems ◽  
Ground Source

To mitigate the effects of climate change, the European Union calls for major carbon emission reductions in the building sector through a deep renovation of the existing building stock. This study examines the cost-effective energy retrofit measures in Finnish detached houses. The Finnish detached house building stock was divided into four age classes according to the building code in effect at the time of their construction. Multi-objective optimization with a genetic algorithm was used to minimize the life cycle cost and CO2 emissions in each building type for five different main heating systems (district heating, wood/oil boiler, direct electric heating, and ground-source heat pump) by improving the building envelope and systems. Cost-effective emission reductions were possible with all heating systems, but especially with ground-source heat pumps. Replacing oil boilers with ground-source heat pumps (GSHPs), emissions could be reduced by 79% to 92% across all the studied detached houses and investment levels. With all the other heating systems, emission reductions of 20% to 75% were possible. The most cost-effective individual renovation measures were the installation of air-to-air heat pumps for auxiliary heating and improving the thermal insulation of external walls.

Cooling Towers as Supplemental Heat Rejection Systems in Ground Source Heat Pumps for Residential Houses in Texas and Other Semi-Arid Regions

2012 ◽  
Author(s):  
Siddharth Balasubramanian ◽  
Jonathan Gaspredes ◽  
Tess J. Moon ◽  
Glenn Y. Masada
Keyword(s):  
Heat Pump ◽  
Cooling Tower ◽  
Cost Effective ◽  
Heat Pumps ◽  
Residential Home ◽  
Test Case ◽  
Pump Efficiency ◽  
Ground Source Heat Pump ◽  
Ground Source Heat Pumps ◽  
Ground Source

Simulation results from a hybrid ground source heat pump model are presented for a residential home that integrates a compact cooling tower into an existing ground source heat pump model. The tower is introduced to assess its impact on the operational and economic performance over that of a GSHP alone. Metrics include initial and lifetime operational costs, ground heating effects, heat pump efficiency, and ability to control the temperature of the conditioned space. A single story, 195 m2 house located in Austin, Texas is used as a cooling-dominated test case. Simulations spanning 10-years of operation show that adding the cooling tower is cost effective, but more importantly, it extends the lifetime of the borehole system and maintains the heat pump efficiencies at high levels.

scholarly journals Emission Reduction Potential of Different Types of Finnish Buildings through Energy Retrofits

Buildings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 234
Author(s):  
Janne Hirvonen ◽  
Juha Jokisalo ◽  
Paula Sankelo ◽  
Tuomo Niemelä ◽  
Risto Kosonen
Keyword(s):  
Emission Reduction ◽  
Life Cycle Cost ◽  
Energy Demand ◽  
Reduction Potential ◽  
District Heating ◽  
Heat Pumps ◽  
Single Family ◽  
Emission Reduction Potential ◽  
Reduce Emissions ◽  
Relative Potential

Energy retrofitting of buildings shows great potential in reducing CO2 emissions. However, most retrofitting studies only focus on a single building type. This paper shows the relative potential in six Finnish building types, to identify possible focus areas for future retrofits in Finland. Data from previous optimization studies was used to provide optimal cases for comparison. Energy demand of the buildings was generated through dynamic simulation with the IDA-ICE software. The cases were compared according to emissions reduction, investment and life cycle cost. It was found that, in all buildings, it was possible to reduce emissions cost-neutrally by 20% to 70% in buildings with district heating and by 70% to 95% using heat pumps. Single-family homes with oil or wood boilers switching to heat pumps had the greatest emission reduction potential. More stringent requirements for energy efficiency could be mandated during building renovation.

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

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.

A Model for a Geothermal Well in a Hydraulic Groundwater Flow for Ground Source Heat Pump Systems

2011 ◽  
Author(s):  
Kevin D. Woods ◽  
Alfonso Ortega
Keyword(s):  
Thermal Conductivity ◽  
Analytical Solution ◽  
Groundwater Flow ◽  
Heat Pump ◽  
Temperature Response ◽  
Ambient Air ◽  
Heat Pumps ◽  
Thermal Reservoir ◽  
Geothermal Well ◽  
Ground Source

Heat pumps are mechanical systems that provide heating to a space in the winter, and cooling in the summer. They are increasingly popular because the same system provides both cooling modes, depending on the direction of the cycle upon which they operate. For proper operation, the heat pump must be connected to a constant temperature thermal reservoir which in traditional systems is the ambient air. In ground source heat pumps however, subterranean ground water is used as the thermal reservoir. To access the subterranean groundwater, “geothermal” wells are drilled into the formation. Water from the building heating or cooling system is circulated through the wells thereby promoting heat exchange between the coolant water and the subterranean formation. The potential for higher efficiency heating and cooling has increased the utilization of ground source heating ventilating and air conditioning systems. In addition, their compatibility with a naturally occurring and stable thermal reservoir has increased their use in the design of sustainable or green buildings and man-made environments. Groundwater flow affects the temperature response of thermal wells due to advection of heat by physical movement of groundwater through the aquifer. Research on this subject is scarce in the geothermal literature. This paper presents the derivation of an analytical solution for thermal dispersion by conduction and advection from hydraulic groundwater flow for a “geothermal” well. This analytical solution is validated against asymptotic analytical solutions. The traditional constant linear heat source solution is dependent on the ground formation thermal properties; the most dominant of which is the thermal conductivity. The results show that as hydraulic groundwater flow increases, the influence of the ground formation thermal conductivity on the temperature response of the well diminishes. The diminishing influence is evident in the Peclet number parameter; a comparison of thermal advection from hydraulic groundwater flow to thermal conduction by molecular diffusion.

Design and Performance of Adsorptive Heat Pumps

2021 ◽  
pp. 223-250
Keyword(s):  
Heat Pump ◽  
Silica Gel ◽  
Heat Supply ◽  
Sodium Acetate ◽  
Energy Performance ◽  
Heat Pumps ◽  
Sodium Sulphate ◽  
Heat Supply Systems ◽  
And Performance ◽  
Supply Systems

The chapter is devoted to design and performance of adsorptive heat pumps. In the first sub-division, state-of-the-art of the adsorptive heat pumping is analyzed. It involves analysing operating principle of adsorptive heat pumps, comparing of the properties of adsorbents used, bed specifications, and operating conditions. Original construction of the adsorptive heat pump is designed by authors for independent heat supply systems or hot water supply of buildings and other structures for various purposes. The composites ‘silica gel – sodium sulphate' or ‘silica gel – sodium acetate' were used as adsorbents. Discharging was performed in a daytime, when heat pump supplied heating system with water warmed to 45 – 35°C. The regeneration mode proceeded at night from 0.00 to 8.00 a.m. Efficiency of suggested adsorptive heat pump is estimated by two methods: as ratio of adsorption heat to sum of desorption heat and external heat supplied to sorbent during its heating up to regeneration temperature (coefficient of performance of cycle) and as ratio of heat of adsorption to heat supplied by solar collector (net coefficient of performance). Suggested heat pump coefficients of energy performance of cycle are stated to be 2.084 when composite ‘silica gel – sodium sulphate' used and 2.021 when ‘silica gel – sodium acetate' used. Seasonal dependence of net coefficient energy performance for suggested adsorptive heat pump based on composites ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' is revealed. Correlation of coefficients of energy performance of adsorptive heat pump and composite sorbents properties (sorption capacity and regeneration temperature) is stated. Insignificant decreasing of coefficients of energy performance when ‘silica gel – sodium acetate' used is explained by lower sorptive capacity as compared to ‘silica gel – sodium sulphate'. Suggested heat pump application perspectives are shown for heat supply systems to result from traditional energy sources independence and environmental advantages. Adsorptive heat pumps development challenges, major limitations for commercialization of adsorptive heat pumping, and requirements to ongoing innovations are analysed. The present chapter can be useful for energy efficient decentralized heat supply systems based on adsorptive heat pump unit.

scholarly journals Sensitivity analysis using simulations for a ground source heat pump – implementation on a solar passive house

2019 ◽  
Vol 111 ◽  
pp. 01070
Author(s):  
Gheorghe Ilisei ◽  
Tiberiu Catalina ◽  
Robert Gavriliuc
Keyword(s):  
Sensitivity Analysis ◽  
Heat Pump ◽  
Fossil Fuels ◽  
Electricity Consumption ◽  
Heat Pumps ◽  
Ground Source Heat Pump ◽  
Passive House ◽  
Modeling Tools ◽  
Ground Source Heat Pumps ◽  
Ground Source

Having in sight the need for a strong reduction in CO2 emissions and the fluctuation of the price of fossil fuels, the ground source resources alongside with the ground source heat pumps are becoming more and more widespread for meeting the heating/cooling demand of several types of buildings. This article targets to develop the thermal modelling of borehole heat storage systems. Trying to emphasize some certain advantages of a GSHP (ground source heat pump) with vertical boreholes, a case study analysing a residential solar passive house is presented. The numerical results are produced using different modelling software like DesignBuilder, EED (Earth Energy Designer) and a sizing method for the length of the boreholes (ASHRAE method). The idea of sizing the length of boreholes (main design parameter and good index in estimating the system’s cost) using two different methods shows the reliability of this modelling tool. The study shows that borehole’s length of a GSHP system can trigger a difference in electricity consumption up to 22%. Moreover, this sensitivity analysis aims to prove that the design of the whole system can be done beforehand just using modeling tools, without performing tests in-situ.

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