[EN] In a context of global warming concern and global energy policies, in which heating and cooling systems in buildings account for a significant amount of the global energy consumption, ground source heat pump (GSHP) systems are widely considered as being among the most efficient and comfortable heating and cooling renewable technologies currently available. Nevertheless, both an optimal design of components and an optimal operation of the system as a whole become crucial so that these systems can have a significant contribution to the attenuation of the global energy problem. The overall objective of this PhD dissertation is to perform the control and energy optimization of an experimental GSHP system installed at the Universitat Politècnica de València, making the control system adaptive to the thermal demand of the building and to the climate conditions. For that purpose, different control strategies are proposed, described, developed, implemented and tested in the system. The optimization of any system requires a comprehensive study of its behaviour, by means of a thorough analysis of all the variables and parameters implied on its performance. Therefore, the first step is to analyse the short-term performance of the system, but also the long-term performance based on the experimental data collected at the installation. Second and prior to developing any optimization strategies, it is important to analyse the optimal configuration of the system according to the objectives targeted. This objective includes the study of the best location for the temperature control sensor and the buffer tank, as well as an adequate size for this buffer tank. Finally, once the behaviour of the system has been fully understood, the components of the system are the most efficient according to the possibilities of the research work and they have been connected adequately, the final objective is to develop control and optimization strategies which optimize the operation of the experimental GSHP system. These strategies target the control of the heat pump compressor, but also and more importantly, the energy optimization of the complete system. The focus is not in optimizing the performance of each individual component, but in optimizing the energy performance of the system working as a whole. In this direction, a first approach which combined a temperature compensation strategy and the variation of the frequency of the water circulation pumps, and hence the flow rate, as a function of the thermal load of the building, was first attempted. The application of this first approach resulted in significant energy savings, but also in a lack of user comfort in some of the offices under extreme weather conditions during summer. Consequently, the control and optimization methodology has been upgraded in a global algorithm (which is the final result of this PhD thesis) which couples both strategies in order to ensure the user comfort while keeping significant energy savings. In brief, this PhD work provides a comprehensive experimental study for the energy optimization of a GSHP system for both cooling and heating operation. Experimental results for a one-year operation period demonstrate important energy savings when compared to the standard control operation, up to 35% in the summer season and 53% in the winter season, while keeping the user comfort. / [ES] En un contexto de creciente preocupación por el calentamiento global y de políticas energéticas internacionales, en el cual los sistemas de climatización en edificios representan una parte importante del consumo energético global, los sistemas de bomba de calor geotérmica están ampliamente considerados como una de las tecnologias de climatización de espacios más eficientes disponibles en la actualidad. Sin embargo, tanto un buen diseño de los componentes como una óptima operación del sistema son de vital importancia para que estos sistemas puedan contribuir de manera significativa a atenuar el problema energético global. El objetivo general de esta tesis doctoral es el control y la optimización energética de una instalación experimental de bomba de calor geotérmica construida en la Universitat Politècnica de València, haciendo que el sistema de control se adapte a la demanda térmica del edificio y a las condiciones climatológicas. Para ello, se proponen diferentes estrategias de control, las cuáles son descritas, desarrolladas, implementadas y evaluadas a lo largo de este trabajo de investigación. La optimización de cualquier sistema requiere un amplio estudio de su comportamiento, analizando concienzudamente todas las variables y parámetros implicados en su funcionamiento. Por tanto, el primer paso llevado a cabo es el análisis de los días típicos de funcionamiento de la instalación, pero también su comportamiento a más largo plazo, a partir de los datos experimentales recogidos. En segundo lugar, y como paso previo al desarrollo de las estrategias de optimización, es importante analizar la configuración óptima del sistema de acuerdo con los objetivos perseguidos. Este objetivo incluye el estudio de la posición del sensor de temperatura empleado para el control y del depósito de inercia, así como el dimensionamiento adecuado de este depósito. Finalmente, una vez se ha analizado en profundidad el funcionamiento del sistema, los componentes del mismo son lo más eficientes posible, y éstos han sido conectados de manera adecuada, el objetivo final es el desarrollo de estrategias de control y optimización energética que optimicen la operación de la instalación experimental de bomba de calor geotérmica. Estas estrategias se dirigen principalmente a la optimización del sistema completo. El objetivo no es optimizar el funcionamiento de cada componente de manera individual, sino optimizar el comportamiento energético del sistema trabajando como un todo. En este sentido, se desarrolló una primera metodología que combinaba la compensación de la temperatura de consigna de la bomba de calor en función de la temperatura ambiente exterior, y la variación de la frecuencia de las bombas de circulación (y por tanto el caudal de agua) en función de la carga térmica del edificio. La aplicación de esta primera estrategia resultó en una importante mejora del rendimiento energético, pero también en la pérdida de confort en algunas de las oficinas climatizadas cuando las condiciones climatológicas eran extremas durante el verano. En consecuencia, la metodología de control y optimización desarrollada fue mejorada dando como resultado un algoritmo global de optimización energética (que es el resultado final de esta tesis), el cual acopla ambas estrategias anteriores de manera que se cumpla el confort del usuario y se mantenga un ahorro de energía significativo. En resumen, esta tesis doctoral proporciona un estudio experimental exhaustivo de la optimización energética de un sistema de bomba de calor geotérmica para la climatización de un edificio de oficinas. Los resultados experimentales para un año completo de funcionamiento del sistema muestran un ahorro de energía significativo en comparación con el modo de control de referencia, hasta un 35% en modo refrigeración y un 53% en modo calefacción, a la vez que se mantiene el confort de los usuarios. / [CAT] En un context de creixent preocupació per l'escalfament global i de polítiques energètiques internacionals, en el qual els sistemes de climatització en edificis representen una part important del consum energètic global, els sistemes de bomba de calor geotèrmica estan amplament considerats com una de les tecnologies de climatització més eficients disponibles en la actualitat pel que fa a la climatització d'espais. No obstant això, tant un bon disseny dels components com una operació òptima del sistema són de vital importància per tal que aquests sistemes puguen contribuir de manera significativa a atenuar el problema energètic global. L'objectiu general d'aquesta tesi doctoral és el control i l'optimització energètica d'una instal·lació experimental de bomba de calor geotèrmica construïda a la Universitat Politècnica de València, fent que el sistema de control s'adapte a la demanda tèrmica de l'edifici i a les condicions climatològiques. Amb aquest objectiu, es proposen diferents estratègies de control, les quals són descrites, desenvolupades, implementades i avaluades al llarg d'aquest treball d'investigació. L'optimització de qualsevol sistema requereix un ampli estudi del seu comportament, analitzant conscienciosament totes les variables i paràmetres implicats en el seu funcionament. Per tant, el primer pas duit a terme és l'anàlisi dels dies típics de funcionament de la instal·lació, però també el seu comportament a més llarg termini, a partir de les dades experimentals recollides. En segon lloc, i com pas previ al desenvolupament de les estratègies d'optimització, és important analitzar la configuració òptima del sistema d'acord als objectius perseguits. Aquest objectiu inclou l'estudi de la posició del sensor de temperatura emprat pel control i del dipòsit d'inèrcia, així com el correcte dimensionament d'aquest dipòsit. Finalment, una vegada s'ha analitzat en profunditat el funcionament del sistema, els components d'aquest són el més eficients possible, i han sigut connectats de manera adequada, l'objectiu final és el desenvolupament d'estratègies de control i optimització energètica les quals optimitzen l'operació de la instal·lació experimental de bomba de calor geotèrmica. Aquestes estratègies es dirigeixen principalment a l'optimització del sistema complet. L'objectiu no és optimitzar el funcionament de cada component de manera aïllada, sinó més bé optimitzar el comportament energètic del sistema treballant com un tot. En aquest sentit, es va desenvolupar una primera metodologia que combinava la compensació de la temperatura de consigna de la bomba de calor en funció de la temperatura ambient exterior, i la variació de la freqüència de les bombes de circulació (i per tant del cabdal d'aigua) en funció de la càrrega tèrmica de l'edifici. L'aplicació d'aquest primer apropament va resultar en una important millora del rendiment energètic, però també en la pèrdua de confort en algunes de les oficines climatitzades quan les condicions climatològiques eren extremes durant l'estiu. En conseqüència, la metodologia de control i optimització desenvolupada va ser millorada resultant en un algoritme global d'optimització energètica (resultat principal d'aquesta tesi), el qual acobla ambdues estratègies anteriors de manera que es complisca el confort de l'usuari i es mantinga un important estalvi d'energia. En resum, aquesta tesi doctoral proporciona un estudi experimental exhaustiu de l'optimit\-zació energètica d'un sistema de bomba de calor geotèrmica per la climatització d'un edifici d'oficines. Els resultats experimentals per un any complet de funcionament del sistema mostren un estalvi d'energia significatiu en comparació amb el mode de control de referencia, fins un 35% en mode refrigeració i un 53% en mode calefacció, a la vegada que es manté el confort dels usuaris. / Cervera Vázquez, J. (2016). Control and energy optimization of ground source heat pump systems for heating and cooling in buildings [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/66748 / TESIS

En Amérique du Nord, le chauffage de l'espace, l'eau chaude, et l'utilisation de la climatisation énergie secondaire plus que toute autre activité au sein de bâtiments, émettant ainsi la majorité des gaz périmètres 1 et 2 serre (GES). La pompe à chaleur géothermique (PCG) utilise un tiers de l'énergie des technologies traditionnelles de fournir un espace de services d'eau chaude et de climatisation. Bien géothermique est une technologie bien établie, les économies d'énergie et les émissions de GES ne sont pas traduits dans leur adoption généralisée. Les mesures de politique publique et les incitations financières adoptées pour promouvoir PCG ont échoué à conduire à une large adoption ou de réduire les coûts. Cette thèse examine l'adoption de pompes à chaleur géothermiques en réponse aux politiques de soutien parmi les adopteurs résidentiels, institutionnels, et la ville-échelle. Données au niveau détaillé du site et des panneaux permettent expériences naturelles sur la réponse des adoptants résidentiels au Canada et aux États-Unis à l'évolution des incitations. À des échelles supérieures, les procédures réglementaires relatives à l'offre de services de l'énergie thermique (TES) a fourni une étude de cas pour l'analyse des modèles d'utilité pour financer géothermique pour les clients commerciaux et institutionnels. Au Canada et aux États-Unis, les incitations financières ont échoué à soutenir l'adoption de la pompe à chaleur géothermique à travers ou après la période de la subvention pour les ménages résidentiels. Pas plus que les incitations conduisent à une diminution des prix dans le temps. Problèmes de resquillage au Canada et une incapacité à faire des incursions dans les zones desservies par le gaz naturel ont brin technologie géothermique. En outre, le coût en capital de pompes à chaleur géothermiques en résulte un coût de cycle de vie plus élevé que la plupart des solutions de rechange. Les avantages de l'économie à l'échelle d'incitations financières pour les pompes à chaleur géothermiques sont limitées au Canada, où la plupart des pompes à chaleur sont importés. TES fournissent innovations convaincantes pour combler les obstacles à des échelles supérieures. TES surmonter équilibrer les contraintes de bilan sur la dette commune aux organisations du secteur public par le financement de biens d'équipement et de rénovation que les paiements de services publics. TES peut surmonter les contraintes de capitaux rencontrés par les développeurs en finançant des équipements à l'intérieur du bâtiment en réduisant les coûts de construction. Cependant, notre étude des marchés publics de cas révèle TES être une approche coûteuse dans le long terme. Les perspectives de cette recherche sont traduits dans les meilleures pratiques et des conseils stratégiques pour améliorer la passation des marchés, accroître la sensibilisation, et aligner les incitations pour une plus grande efficacité. / In North America, space heating, hot water, and air conditioning use more secondary energy thanany other activity within buildings, thus emitting the majority of scope 1 and scope 2 GreenhouseGases (GHG). The Ground Source Heat Pump (GSHP) uses one-third the energy of traditionaltechnologies to provide space conditioning and hot water services.While GSHP is a well-established technology, the energy savings and lower GHG emissionshave not translated into their widespread adoption. Public policy measures and financialincentives adopted to promote GSHP have failed to lead to broad adoption or lower costs. Thisthesis examines the adoption of GSHP in response to supportive policies among residential,institutional, and city-scale adopters.Detailed site-level and panel data permit natural experiments on the response of residentialadopters in Canada and the US to changing incentives. At higher scales, regulatory proceedingsconcerning the offering of Thermal Energy Services (TES) has provided a case study for analysisof utility models to finance GSHP for commercial and institutional clients.In Canada and the US, financial incentives failed to sustain the adoption of GSHP throughout orafter the period of subsidy among residential households. Neither did incentives lead to adecrease in price over time. Free-ridership problems in Canada and an inability to make inroadsto areas served by natural gas have stranded GSHP technology. Further, the capital cost ofGSHP results in a higher lifecycle cost than most alternatives. The economy-wide benefits offinancial incentives for GSHP are limited in Canada, where most heat pumps are imported.iiiTES provide compelling innovations to bridge barriers at higher scales. TES overcome balancesheet constraints on debt common to public sector organizations by financing capital equipmentand renovations as utility payments. TES can overcome capital constraints faced by developersby financing equipment inside the building lowering construction costs. However, our casestudy of public procurement reveals TES to be a costly approach in the long run. The insightsfrom this research are translated into best practices and policy advice to improve contracting,increase awareness, and align incentives for greater efficiency.

Vertical ground source heat pumps are established and still growing on the global market. The modelling of these systems is important for system design and optimization. This is an active field of research, and many models are often built into system simulation software such as TRNSYS. With the intention of having a better sensibility for existing TRNSYS tools, three different cases are simulated with several TRNSYS tools, so called Types. A Thermal Response Test, a large borehole field of an IKEA building complex in Sweden, as well as the Marine Corps Logistic Base in Albany, USA. The vertical ground heat exchanger types 203, 244, 243, 246, 451, 55a and 557b are used. Most of the simulations are investigated and evaluated by comparing them to measured data. The result shows that, for these specific cases, the DTS types 557a and 557b can underestimate the heat transfer early on due to a poor consideration of the thermal capacity inside the borehole. Depending on how the thermal resistance is calculated by a module, the fluid mean temperature simulation is affected by a constant throughout the simulation time. The simulation results indicate that the type 557b, where the borehole resistance is pre-set as an input and known from experimental data, is the most accurate of the types for groundwater filled boreholes. On short term, type 451 provides a good coherence with the measured data, with a relative deviation of 10.3 %. The borehole models that consider the borehole thermal capacity overestimate the short term heat transfer rate, whereas those that neglect the borehole capacity underestimate the short term thermal heat transfer on short term. Existing Types describe successfully the long term behaviour of large borehole fields. Serial versus parallel coupled BHE fields show relatively small differences in performance when simulated with type 557b for a specific study case.

No description available.

Interest in indirect (secondary) refrigeration systems has grown since the discovery of the negative effect of environmentally hazardous refrigerants and leakage problems from direct expansion systems. Among the positive effects of indirect systems are: decreased quantities of primary refrigerant, factory built units and confinement of refrigerant to the machine room. Ground source heat pumps, ice rink and indirect system solutions for supermarket refrigeration are examples where indirect refrigeration systems are being used in Sweden. The secondary fluids circulating in the secondary systems are of great interest as its choice can affect heat transfer process; the overall performance of system; corrosion problems and maintenance costs as well as acceptable risks for the environment in case of leakage from the secondary system. A secondary fluid should have low viscosity, high thermal conductivity, high volumetric heat capacity, low freezing point, be non-corrosive, non-explosive, non-flammable, environmentally friendly, non-toxic, give low pressure drop in the system, have good material compatibility, chemically stable and have low cost. The market for secondary fluids worldwide and in Sweden is complex and a comprehensive overview of the available secondary fluids has not been available. The purpose of this thesis is to compile most of the existing secondary fluids on the Swedish market and present them briefly in this report. Different brands of secondary fluids on the Swedish market based on ethylene and propylene glycol, ethyl alcohol, potassium formate, potassium acetate, calcium chloride and other blends are presented in the thesis. Some of the most common brands are: Eco MPG, Dowcal 200, Dowcal N, Zitrec FC, Zitrec LC, Antifrogen L, Frigogel Neo, Heliogel CS80, Brineol MPG, Glytherm 20, Zitre MC, Dowcal 100, Antifrogen N, Neutragel Neo, Brineol MEG, Glytherm 10, Antifrogen Sol HT, Freezium, Hycool, Antifrogen KF, Brine 25, Swedbrine 25, Brenntag KBS, Brineol Bioethanol, E-Therm KBS Bio, Thermol, Zitrec S, Temper, Pekasol 50, Pekasol 2000, Greenway RTU, Greenway Heat Pump -30, greenway Solar -30, Thermera R and Thermera AC. Additionally, it is important to underline that a permit for installation of ground source heat pumps in Sweden is required. Swedish laws and regulations regarding secondary fluids and ground source heat pumps are complex and difficult to overview on municipalities’ levels.

The real performance of ground source heat pumps systems are not precisely highlighted in most cases, especially when it comes to installations older than the contractors guarantee period of 5 years. This project analyses measured data, constructs durability diagrams and establishes an energy balance of a whole heating system located in Saltsjöbaden. The system, composed of 3 heat pumps with a total heating power of 270kW and an oil burner, is used to deliver comfort heat through radiators and ventilation as well as tap warm water production. The installation was originally designed with two oil burners now used as an auxiliary heat supplier. Two heat pumps were installed in 1999 and a third unit was added in 2009. However, the oil consumption has been higher than expected. An experiment with controlled oil burner operation confirmed the need of implementing a control strategy. Some weaknesses in the system are pointed out.

Nowadays, Ground Source Heat Pumps (GSHPs) are more frequently acting as a main or the only device covering the building heat/cool demand. The most efficient way to extract/dissipate the low-temperature heat from/to the ground is by means of Borehole Heat Exchanger (BHE). In this Master of Science Thesis various aspects related to this technology are studied, focused on summarizing the possibilities of installing this tech-nology in Poland. Borehole drilling methods used in Poland and Sweden are analyzed and the most proper and economical ones according to Polish geological structure are proposed. Approximately for 80 % of Poland the ground should be penetrated with Mud Rotary Drilling, while for the rest 20 % DTH Air or Water driven hammer should be used. Solutions of Thermal Insulated Leg (TIL) Borehole Heat Exchanger cooperation with mechanical ventilation system are proposed and simple preliminary estimations show higher Coefficient of Performance (COP) in comparison to normal, common situation, where standard U-pipe BHE works. The possibility of using a new product (Energy Capsule - EC) in Polish conditions is surveyed, found hard to prosper at Polish market according to its high costs. Profitability of Ground Source Heat Pumps with Borehole Heat Exchanger in different geological regions of Poland is investigated. After conducted simulations it occurred that Polish lowland regions are cheaper in exploita-tion, while uplands regions are less expensive at investment level. Finally, the most ef-ficient BHE conception from those currently available at market as well as recently in-vented is suggested. Annular coaxial BHE in a form of Energy Capsule seems to be the most beneficial from all designs taken into account during performed simulations because of its low price and good thermal properties.

Ground-source heat pumps systems (GSHP) are commonly used all over Sweden to supply heat and sometimes cool to different kinds of housings or commercial facilities. Many large installations are by now between 10 and 20 years old. Even when the design of such system has been tackled, rare are the studies that have dealt with following their performance throughout time in detail. Based on conductive heat transfer, the heat extraction process makes the ground temperature decrease when installations are only used for heating. This thesis aims at proposing a method to evaluate how the temperature in a borehole heat exchanger of a GSHP will evolve. The project is focusing on the heat transfer from the ground to the boreholes modelled using Finite Line Source (FLS) based generated g-functions. “g-functions” are non-dimensional parameters characterizing the evolution of the ground thermal resistance enduring variable heat extraction loads. A model using Matlab has been developed and validated against relevant publications. As a case study, the method is applied to an existing 15 years old GSHP installation, composed of 26 boreholes and 3 heat pumps, so as to compare the obtained results with data measured on site. Two sub-borehole fields compose this installation: 14 of them were drilled in 1998 and the remaining 12 in 2009. Measured variable heat extraction loads were superposed using dedicated site g-functions for the two boreholes fields. As a result, a comparison between modelled and calculated heat carrier fluid in the boreholes over the last 6 months is presented here, as well as a 20 years forecast of the ground temperature at the interface with the boreholes.

In 2010, the Ground Source Heat Pumps (GSHPs) market in the European Union went up over one million (1 014 436 units at the end of 2010 according to EUROBSERV’ER 2011). In 2011, it was estimated around 1.25 million according to Bayer et al. (2012). With more than 378 000 units installed in 2010, according to the Swedish heat pump association (SVEP), the Swedish GSHPs market was the first in the EU. As for the French GSHPs market, it was estimated to 151 938 units in service in 2010, which propelled France at the third rank in the EU. However, despite a relatively important number of GSHPs installed in the whole EU, since 2008 GSHP sales have shrank. Even Sweden which has been the most competitive country sees its GSHP sales decline in the first quarter of 2012 (EUROBSERV’ER 2011). This report is the achievement of my Master of Science Thesis project. It also represents the end of my studies at INSA Lyon in France and concludes my degree in Energetic and Environment Engineering. This report deals with the improvement of a heat injection apparatus which is available at KTH (Royal Institute of Technology). This equipment is better known as Thermal Response Test (TRT) apparatus. This kind of equipment improves Borehole Heat Exchangers (BHE) design in terms of size and cost benefits. This technology is generally used to design GSHP installations in both domestic and industrial purposes. It allows to determine really important thermal BHE parameters: the thermal conductivity of the ground and the borehole thermal resistance. The report covers a theoretical description of TRT experiments, the reasons and objectives of such a project, the apparatus design and its construction. The last part is dedicated to a first experimental laboratory results and some problems met during the project course.

The International Energy Agency’s Global Status Report 2017 estimates that existing buildings must undergo deep energy renovations, which reduce the energy intensity of buildings by 50% - 70% in order to achieve the “Beyond 2°C” scenario [1]. Many buildings in Bitola, The Republic of North Macedonia, will need considerable upgrades to meet these goals. Among them, health care facilities and education centers have the greatest potential, with energy savings that could reach 35 to 40% [2]. PHI Clinical Hospital Bitola is the largest health care facility in the southwestern region of North Macedonia with a capacity of 500 beds, providing care to almost 300.000 patients annually. It has a heating system based on heavy fuel oil, and an inefficient distribution system which has not been upgraded since the 1970s. There is no centralized ventilation or cooling systems, making it necessary to open and close windows in order to regulate the indoor temperature and generate natural ventilation. This study aims to replace the use of heavy fuel oil (HFO), reduce building related GHG emissions, and increase the primary renewable energy fraction of PHI Clinical Hospital Bitola, by investigating a replacement energy system using heat pumps and solar energy. Special consideration is given to increasing the level of comfort of patients and improving the safety of the indoor environment. Space conditioning, domestic hot water, and electricity demands for three critical buildings are considered in Polysun over a 1-year period. The costs and benefits of technologies including air and ground source heat pumps, solar photovoltaics, and ice thermal energy storage are analyzed. It is determined which of these technologies can be implemented in an energy and cost-efficient manner in the Republic of North Macedonia, thus contributing to the reduction of building related greenhouse gas emissions and other pollutants that contribute to poor air quality. Ground source heat pumps perform superior to air source heat pumps, however, the total life cycle costs of ground source heat pump systems are much higher than air source heat pump systems, making the marginal gains in the technical performance not worth the investment in a borehole field. When using ice thermal energy storage within the cooling and domestic hot water systems the benefits of improved heat pump performance and reduced electricity consumption are not observed. The configuration of thermal storage tested here uses the domestic hot water system to withdraw heat from the thermal storage tank, creating ice, which is then used to decrease the need for cooling using the chiller. However, the cooling load is much larger than the hot water demand, and so any ice generated in the tank is depleted within the first few days of cooling. Many other configurations and control strategies for thermal storage exist which could be the subject of further research. When selecting a renewable energy system that could replace the current HFO boiler in the hospital, the results of this study suggest that an air source heat pump system with solar PV is the recommended solution. For buildings 1 and 2, the final results achieved a primary renewable energy fraction of 62%, a GHG emissions savings of 840 tons of CO2eq equating to a 26% reduction, coming at a capital cost of nearly 2,7 million €, and reducing annual energy expenses by 47%. For building 4 the final system delivers a primary renewable energy fraction of 64%, GHG emissions savings of 109 tons CO2eq or 17%, while costing 0,67 million € in capital expenses and lowering annual energy expenses by 50%. / Den internationella energi byråns globala status rapport 2017 uppskattar att existerande byggnader måste undergå djupgående energi renovationer, som ska reducera byggnadernas energiintensitet med 50% - 70% för att uppnå i scenariot “Beyond 2°C” [1]. Många byggnader i Bitola (Republiken av nora Makedonien), kommer att behöva betydande uppgraderingar för att uppfylla dessa mål. Bland dem har hälsovårdsanläggningar och utbildningscenter den största potentialen, med energi besparingar där dessa kan uppnå 35% till 40% [2]. PHI Kliniskt Sjukhus Bitola är den största sjukvårdsanläggningen i den sydvästra regionen av Nora Makedonien med en kapacitet på 500 sängplatser, som ger vård till nästan 300.000 patienter årligen. Det nuvarande värmesystemet är baserat på tung eldningsolja och ett ineffektivt distributionssystem som inte har uppdaterats sedan 1970-talet. Det finns inga centraliserade ventilations- och kylsystem, vilket gör det nödvändigt att öppna och stänga fönster för att reglera inomhustemperaturen och generera naturlig ventilation. Denna studie syftar till att ersätta användningen av tung eldningsolja, minska byggnadsrelaterade växthusutsläpp och öka den primära förnyelsebara energifraktionen av Kliniskt Sjukhus Bitola. Genom att undersöksöka ett ersättande energisystem med värmepumpar och solenergi. Särskild hänsyn tas till öka patienternas komfort och förbättra säkerheten i inomhusmiljön. Värme och kyla, varmvatten och el-krav för tre kritiska byggnader betraktas i Polysun under en 1- års period. Kostnaderna och fördelarna med tekniken inklusive luft och markvärmepumpar, solceller och termisk energilagring analyseras. Det fastställs vilken av dessa tekniker som kan implementeras på ett energi- och kostnadseffektivt sätt i Republiken av nora Makedonien, vilket bidrar till att minska byggnadsrelaterade växthusgasutsläpp och andra föroreningar som kan bidra till dålig luftkvalitet. Markvärmepumpar har högre prestanda än luftvärmepumpar, men de totala livscykelkostnaderna för ett markvärmepumpsystem är mycket högre än för ett luftvärmepumpsystem. Vilket gör den marginella vinsterna för den tekniska prestandan inte värda investeringen av ett borrhåls fält. Vid användning av is som termisk energilagring och kylning och varmvattensanläggningar, tog ingen hänsyn till fördelarna med en förbättrad värmepumps prestanda och minskad elförbrukning. Konfigurationen av termisk lagring som testas här använder det inhemska varmvattensystemet för att ta bort värme från den termiska lagringstanken, vilket skapar is som sedan används för att minska behovet av nedkylning av byggnaden. Kylbelastningen är emellertid mycket större än varmvattenbehovet. Vilket betyder att all is som genereras i tanken används upp efter några dagar av kylning. Många andra konfigurationer och styrstrategier för termisk lagring finns och kan vara till ändamål för framtida forskning. När val av ett förnybart energisystem görs som ska kunna ersätta den nuvarande tung eldningsolja pannan på sjukhuset antyder resultatet av denna studie att ett värmepumpsystem med luftkälla och sol-PV är den rekommenderade lösningen. För byggnad 1 och 2 uppnådde det slutliga resultatet en primär förnyelsebar energifraktion på 62%, vilket skulle innebära en besparing av växthusgasutsläpp med 840 ton CO2 ekvivalenter. Vilket motsvarar en minskning med 26%, med en kapitalkostnad på nästan 2,7 miljoner €. Samt minskade årliga energikostnader med 47%. För byggnad 4 levererar det slutliga systemet en primär förnybar energifraktion på 64%, med en -5- besparing av växthusutsläpp på 109 ton CO2 ekvivalenter eller 17%. Medan det kostar 0,67 miljoner € i kapitalutgifter och sänker den årliga energikostnaden med 50%.