This study is about the impact of early design decisions on the heat demand of a small residential building. Heat demand is a significant part of the energy use of residential buildings in the Netherlands. Reducing this demand will reduce the strain on national energy resources and even allow buildings to become energy neutral or independant with the addition of energy supply and storage systems. Based on a case study building of 8 appartments, the simulation study explores the impact of several individual design aspects: insulation, orientation of glass facades and building shape. Furthermore the balcony facade of the case study building is compared to a plain facade and a sunspaces (balconies with a glass facade) in terms of heat demand and comfortable use (operative temperature). Based on these studies the case study building is completely re-designed with the goal of reaching a minimal level of heat demand. Based on these studies and the re-design a final set of design guidelines is developed for designers interested in designing small residential buildings with low heat demand.

This research focusses on providing guidelines on how energy flat multifunctionalurban blocks can be designed, including governance components.   First of all, architectural design can play a significant role in reducing themismatch over time. With architectural design the space heating demand can bereduced and the cooling demand can be increased. Additionally, for well-insulatedbuildings the energy system that is most suited largely depends on thefunctional program of the area. When the area has a lot of functional area witha high heat-cold ratio, i.e. more cooling demand than heating demand, energyexchange can increase its autonomy. With the introduction of continuous coolingeven more energy can be exchanged between functions and the energy system isless dependent on other technologies to supply heat other than subtracting heatfrom the building itself and use it as heat source.         For energy flat multifunctional urban blocks optimization of the overall energysystem through stakeholder collaboration and integral technological approach isa key component. Hence, these energy systems are becoming quite complex. Inorder for the concept of energy flatness to be taken up the supply, paymentregulations and distribution of energy within an urban block should befinanced, maintained and operated by a third party, an Energy servicecontracting company (ESCO).

The building sector uses 40% of the primary energy worldwide. Energy demand in a non-residential existing building is rising due to higher comfort conditions, population growth and the enhancement of the building services. On the other hand, renewable energy technologies are every time more accessible for the built environment, especially the ones that use the sun as their primary energy source. The difference between that energy demand and that production of energy in existing buildings is causing a mismatch of energy that needs to be solved if problems such as an increase in the electricity bills, an oversized energy grid or the dependence on fossil fuels want to be avoided. Currently there is not research on how to reduce the mismatch in non-residential existing buildings; therefore, this research aims to be the beginning of the exploration of this topic. By matching the energy demand and the energy produced at any point of time within the building boundary, the building will be energy flat. During this research, the renovation of a case study building towards energy flatness was proposed. A three steps strategy was proposed to reduce energy demand, produce renewable energy and integrate a complementary energy system in existing buildings that want to be renovated towards a full energy balance and a renovation proposal of a case study building towards energy flatness. As a result, energy flatness in the renovation of non-residential existing buildings is limited to the extent of their physical and functional parameters which restrains the energy demand, production and distribution. Furthermore, the three steps strategy helped to reduce the energy mismatch and is relevant because the energy mismatch problem is going to be every time more visible in the built environment.

The problem that needs to be resolved is the fact that there is too little knowledge about the energetically optimal application of photovoltaic thermal collectors (PVT) in an energy system configuration as well as its integration in a building envelope. A solution for this problem could eventually entail an optimisation in the use and storage of solar energy. The technology of PVT is very promising in relation to the current energy transition, most certainly as an incentive to foster the use of renewable energy sources and technologies. That is why the development of a PVT system configuration with additional envelope-integration is treated in this thesis. The main purpose of this thesis is to expound the energy concept of PVT, its role in the system configuration and its facade-integrational aspects, all this in relation to the application of PVT on a multi-family case study building. The accompanying research question is: How can an energy concept with PVT be optimised or maximised in terms of renewable energy and be integrated in the envelope of a multi-family building? In order to give an unambiguous answer to this question, the energy concept of PVT and other relevant technologies will be explained in a literature and background study upfront. This is followed by the description of the case study building. After that, the development of the PVT output types, configurations and the development of the system configuration and operation modes are discussed. The energy requirements of the multi-family building together with the energy output of the PVT collector results in an energy balance. Finally, the facade-integration aspects of PVT are described, where the amount of collectors on the roof and in the facade are determined by the energy balance. It was shown that a PVT collector that is glazed on the top and insulated at the back is the most effective type in the light of this thesis, that is to say in combination with this specific multi-family building. In addition to this, several collectors in series will lead to an effective configuration. Besides, for an efficient utilisation of the (collected) energy, it is wise to apply low-temperature heating as well as an energy storage in the system configuration. For the integration of PVT into a multi-family building, it is first of all recommended to design a proper layout for the in- and outcoming distribution pipes. Finally, in order to improve the integrational flexibility, it is advised to introduce multiple dimensions of PVT collectors in the future.

The post-war building stock represents 33% of all residential buildings. A common characteristic is that they are poorly insulated compared to the current Dutch building regulations. This research will focus on post-war walk-up apartments, they account for approximately 8% of the total residential building stock. 70% out of this 8% is social housing. All housing corporations agreed that in 2020 the residential portfolio should have an energy label which is at least B. The refurbishment of post-war walk-up apartments is really needed to achieve this energy label. The 2ndSKIN approach is a prefabricated system for the renovation of walk-up apartments. This approach contains a zero-on-the-meter concept, where building services are integrated into the façade. The 2ndSKIN approach is still too costly and the zero-energy target is only met in specific conditions. To optimize the retrofit of residential buildings different energy systems should be applied. The approach can then be used in different urban contexts, which will result in upscaling the refurbishment of walk-up apartments. Literature research on several existing renovation approaches and different energy systems has been conducted. Together with the analysis of post-war walk-up apartments, it resulted in four main energy systems. These concepts have been simulated with the software Uniec2.2. The goal of the simulation was to achieve the BENG regulations (Bijna Energie Neutrale Gebouwen [Almost Energy Neutral Buildings]). In order to achieve the BENG regulations, a low and high impact variant have been designed. These variants differ in insulation value and how ventilation is provided. The conclusion of the simulation provided direct input for the design phase. A case-study is used to apply the outcomes of the simulations in detail and to design an approach where it is possible to accommodate different energy systems. The outcome of this research is a prefabricated renovation approach for post-war walk-up apartments that is applicable to accommodate energy saving measures with different energy systems. Building services are integrated into the façade and different building services units can be placed in the backyard to have different energy systems in the building. With the new building services and the increased insulation value of the building envelope, it is possible to fulfil the BENG regulations with a post-war walk-up apartment building. Except for one concept, all other concepts are even zero-energy. The different energy concepts and variants for the building envelope have been included in a decision-making diagram. With this diagram, housing corporations or homeowners associations can choose between the different concepts, based on three different goals. Also, some considerations concerning the choice between the low and high impact for the building envelope are made.

The global energy demand is increasing as a result of population growth and increased wealth standards. The share of local renewable energy supply is also increasing, driven by the urge to mitigate climate problems. Residential energy demand and renewable energy supply are both intermittent; the demand profile depends on several aspects like the inhabitants, the physical properties of a building and the outdoor climate. Renewable energy supply is intermittent because it can only occur when the intermittent renewable energy source, e.g. the sun, is present. So, the intermittencies of supply and demand depend on different aspects, hence cause a mismatch. This mismatch must be solved. Energy-flat buildings are a potential solution to this problem. To diminish the problem of energy mismatch on a residential level, dwellings will have to be able to adapt the demand to supply and vice versa. The research presented in this thesis explores the potential of architectural design in eliminating the on-site energy mismatch. In other words, the potential of energy-flat buildings. First, three key-performance indicators for energy-flatness are defined and a dynamic energy simulation model is set-up using Grasshopper Honeybee software. With this tool, the energy-flat performance of several designs can be quantified and analysed. Then, the current mismatch of residential energy in a reference design is determined. Thereafter, the effect of building parameters on the energy-flat performance of a design is researched. The results of this parameter study are then used to design an energy-flat building. The knowledge gained by this design-by-research approach is bundled in a toolbox, which serves as a guide for architectural designers. It is found that the heat balance should be considered first when aiming for energy-flatness, rather than the electricity balance. The nine building parameters researched, all significantly influence the energy-flatness by affecting different elements of the heat balance. An adaptive approach in terms of daily and seasonal differences is required for almost all parameters to achieve the best energy-flat performance. The largest challenges for energy-flatness are the lack of supply potential at night, lower solar power in winter combined with lower outdoor temperatures and the unpredictability of both energy demand and energy supply in short time intervals. The toolbox that is created provides effective energy-flat design principles. Moreover, it is concluded that architectural design can significantly contribute, but not completely solve the mismatch of residential energy demand and supply. The performance of building installations is essential for achieving energy-flatness, but it is only partly researched in this thesis because these building installations lie beyond its scope. Lastly, it is concluded that energy-flat buildings theoretically can be the solution to the (inter)national energy balancing challenge, but it is preferable to distribute the challenge over multiple levels of the system. The relevance of energy-flatness will change in the future, depending on the development of energy storage technologies and the share of renewable energy production. Altogether, the architecture of a building can significantly influence its energy-flatness and the concept of energy-flatness will contribute to effective use of local renewable energy.

Spatial impact of the energy transition is a subject that has not been studied extensively as of now. Developing a spatial plan for a sustainable energy system in an early phase will provide insight in practical and spatial implications that are related to these systems. This is especially relevant in existing neighbourhoods, where the existing context has to be taken into account. Energy potential mapping already connects energy production to a spatial component, but it remains theoretical and abstract, often until a late stage in the planning process. An additional step should be taken to assess the spatial impact of the renewable energy production and the district energy system through concrete design proposals; creating the “toolbox”. These designs are different based on the technology and the context of the project, but it should always seek for ways to minimise its negative impact or to benefit its surroundings. By doing this, the components of the system becomes tangible and a tool to discover synergies, make decisions, and convince stakeholders. This will not only improve the feasibility of the project, but also the quality of the final product.

The transition from fossil fuels to renewable energy sources brings along the reduction of the supply temperature of the distribution heating networks, because renewable energy sources usually provide heat at lower temperatures. This master thesis specifically focuses on the buildings because it is uncertain which adaptations are necessary to ensure thermal comfort when the supply temperature decreases. Especially in existing buildings, since they were originally designed for high operating temperatures. A case study was conducted by studying the performance of a non-residential building under different simulated scenarios to enable lower operating temperatures in the heating network. The objectives of the research are two: 1) to develop of a protocol for data collection and selection of promising adaptations that facilitates a case study on this topic and 2) to compare the observed effects of the different possible adaptations on the required operating temperatures in this case study with the results of the few other studies available. The most interesting results derived from the case study are that it is possible to lower the peak power, and thus the operating temperatures, in the current situation of the selected building, without any adaptation, from 78/70oC to 63/55oC. Assuming that the mass flow is decreased in order to achieve a bigger temperature difference between supply and return, operating temperatures can be 70/50oC. Mass flow control through radiators should then be implemented in order to obtain the lowest possible return temperature for a given supply temperature. During the implementation phase of the geothermal project, the implications of this measure need to be studied. When heat losses are small, smart settings in the building management system prove successful to lower the supply temperature further. In the controls and operation scenarios, adjusting the room temperature setpoints and the heating schedules enables even lower supply and return temperatures, 50/35oC. In old, poorly insulated buildings, minimal renovations in the buildings’ envelope are crucial (and often sufficient) to enable low temperature heating. When the building without renovations was simulated, it was not possible to lower the operating temperatures; instead, the required temperature increased to 90/70oC. Changes in the energy system, such as the installation of radiators designed for lower temperature heating, also enable supply and return temperatures of 50/35oC. The case study building has a ventilation system with heat recovery and pre-heating of air to 19oC. A scenario is simulated with a system with only heat recovery. The ventilation air is introduced in the room at lower temperatures, and the heating system takes over the heat demand. For the same operating temperatures, 70/50oC, the heat recovery scenario suffers a decrease in the thermal comfort. Seeing the effect of the heating through ventilation air in lowering the supply and return temperatures, a central ventilation system with heat recovery and pre-heating that can operate at low temperatures can represent a good alternative to other decentralised adaptations in the energy system, such as changing radiators. The protocol for data collection and selection of promising adaptations created during this research facilitates the first stages of a case study, by providing an inventory of the main elements for the data collection and their implication in lowering the operating temperatures in the heating network. It also presents a list of possible adaptations to enable low temperature heating. Future case studies could focus on fixing thresholds for the properties of the envelope that limit the lowering of the supply and return temperature. Further research could also continue exploring the optimisation of schedules and room temperature settings to lower the temperatures in the heating network even more, considering the possibility to use the thermal mass of the building as passive storage. Generalisations from case study findings are necessary to start developing one common standardised procedure, with recommended tools and guidelines for simulation as well as practical tests. The standard procedure at building level ought to be included as part of a holistic district level and building level approach in order to facilitate the transition to more efficient and sustainable heating networks.

Om in 2050 een energie neutrale woningvoorraad te hebben is renovatie belangrijk. In deze scriptie is onderzocht hoe portiekflats gerenoveerd kunnen worden. Hiervoor zijn zeven scenario’s gesimuleerd: spouw isolatie; voorzetwand; binnen isolatie met Kingspan panelen; voorzetgevel; buiten isolatie met Rc-panels en een nieuwe gevel. Deze scenario’s deze beoordeeld op vier aspecten: de kosten, de energie prestatie, de mogelijkheid voor lage temperatuur verwarming en het implementatie gemak. Hieruit kan geconcludeerd worden dat lage temperatuur verwarming mogelijk is vanaf 4 m2K/W. Wanneer de ramen en ventilatie ook worden verbeterd (bijvoorbeeld met driedubbel glas en ventilatie met warmteterugwinning) zal dit misschien veranderen.

Architectural design greatly influences building energy performance (BEP), and energy-efficient design is therefore often studied. Architectural space layout also can affect BEP. However, only a few of the numerous studies on energy-efficient design considered the effect of space layout. Within these studies, the isolated effect of space layout on the BEP has hardly have been analysed systematically. The framework of Performative Computational Architecture (PCA) had been proven to be effective to improve BEP. PCA includes form generation, performance evaluation, and computational optimisation. With this framework, the building’s geometry and material properties are parametrised, and the performance is assessed for different combinations of design parameters. It aims to find the proper parameters that satisfy the defined objectives. This method can include the generation and assessment of space layouts. However, only a few studies have tried to combine the automatic generation of space layout with energy performance optimisation; nor the systematic analysis of the effects and relations between space layout and energy performance.@en

The demand of energy increases steadily due to the growing global population and the increasing living standard of emerging markets. The increasing energy demand and reduction of greenhouse gasses require a significant increase of renewable energy sources and energy efficiency of buildings. Also, the increasing degree of renewable energy sources increase the demand to store excess energy and to bridge the gap between energy production and consumption. This thesis focusses on the possible energy reduction for air-conditioning systems by the application of thermal energy storage and phase change materials (PCMs). Tetra-n-butylammonium bromide (TBAB) is a promising PCM for air-conditioning applications. PCMs store thermal energy in the form of latent heat. PCMs are also promising cold storage media because of the capacity to store energy at constant or near constant temperature. TBAB has a high solubility in water and hydrate crystals are formed in a TBAB aqueous solution at temperatures from 0-12.5 °C depending on the concentration of TBAB in the solution. The solid mass fraction of the slurry is limited to maintain the slurry pumpable. A pilot system to control the temperature of a 144 m² space is installed. The system is equipped with multiple sensors to monitor the system. The air-conditioning system consists out of a primary loop, which uses the conventional refrigerant R134a, and a secondary loop, which uses a TBAB solution as distribution fluid. An initial mass fraction of 36.5 wt% TBAB is used, resulting in a phase equilibrium temperature of approximately 12.5 °C. The hydrate crystals are produced in the generator and stored in a storage vessel of 300 l. The capacity of the air-conditioning system is around 3.5 kW. The pilot system is modelled with both water and a TBAB solution as secondary distribution fluid by improving and extending an existing model. The crystals are produced in the generator by evaporation of the primary refrigerant. The crystals are removed from the heat transfer surface by the friction of the flow. The crystal layer thickness and flow velocity in the generator are calculated by comparing the friction losses to experimental determined scrapping forces required to remove the crystals. Experimental data of the pilot plant are used to validate the model. The model simulations of the air-conditioning system show a COP increase from 3.27 to 4.30 when a 36.5 wt% TBAB solution is used as a secondary distribution fluid instead of water. Simulation results show also an increased performance when the initial mass fraction of TBAB is lowered to 35 wt%. The COP of the system increased to 4.50 mainly due to the reduction of the energy consumption of the compressor. The force required to remove the crystals from the heat transfer surface lowers by lowering the initial mass fraction of TBAB. Therefore, the steady state crystal layer thickness in the generator reduces, increasing the heat transfer rate by lowering the thermal resistance. However, reducing the initial TBAB mass fraction also lowers the evaporation temperature of the primary refrigerant and the total cooling capacity of the slurry.

This research is about the spatial integration of a self-sufficient renewable energy system in selected urban blocks in the neighbourhood Ramplaankwartier in Haarlem, providing the heat demand of the residential buildings located in these selected urban blocks. Solar energy production and thermal energy storage are the selected energy production and storage methods included in this report. These methods are the result of a literature study and its demarcation results. Based on a spatial analysis resulting in energy potentials, ten configurations are set up for the integration of a renewable energy systems. These configurations are divided over three categories with different principles for an energy transition project: (A) 100% gas replacement using the commonly applied placement of panels on roofs. (B) 100% gas replacement using an analysis of energy potentials (C) Configurations aiming for minor spatial impact on the selected urban blocks taking into account the wishes of inhabitants.These ten configuration were assessed on their quantifiable spatial & energy characteristics using a set of selected/modified spatial & energy indicators. Secondly a perceptual analysis was employed on a pilot group of inhabitants during an information night. During a presentation of the configuration results questionnaires were filled in by inhabitants.The results of the quantifiable and perceptual analysis are compared using the the following criteria: energy potential, spatial impact, inhabitants acceptance, amount of m2 used energy production panels & necessary additional technologies. The configuration (C.4), using PVT + large scale heat pump + pit thermal energy storage, is the optimal solution of the investigated energy solutions.Purely based on the energy characteristics replacing 100% of the gas use, the best option would be (combination of configurations C.3 & C.4) using PVT + large scale heat pump + latent thermal energy storage.If spatial/visual impact in the public space of an energy transition project is not possible or there is an aim for zero spatial/visual impact of stakeholders, then the B.1 or C.2 configuration, using flat-plate collectors + pit thermal energy storage (without covered parking), is the best option.This thesis hopes to contribute to speeding up the process of energy transition projects, replacing the gas produced heat demand with a renewable produced heat demand, for the existing built environments in the Netherlands.