In order to reach the goal of a zero emission building (ZEB), CO2 emission data has to be made available and verified for traditional building materials, new ‘state-of-the-art’ building materials and the active elements used to produce renewable energy. However, an initial literature review found that although there are databases of embodied carbon values for most building materials, the range in results for some materials are varied and inconsistent.
This paper follows on from previous work on the development of a transparent and robust method to calculate CO2eq emissions of the materials used in the concept analysis of the ZEB residential model, single family house. The aim of the concept analysis was to investigate if it was possible to achieve an "all-electric" ZEB-building by balancing operational and embodied emissions by PV-production on the building. The analysis has not considered minimising the embodied emissions but is rather a documentation of the embodied carbon dioxide emissions using traditional materials in the envelope and in the ventilation and heating systems, as well as, those associated with the renewable energy system, such as the photovoltaic panels and solar thermal collectors. Material inventories have been imported from the Revit BIM model, via MS Excel. The material inputs are structured according to the Norwegian table of building
elements, NS 3451-2009 and emission factors (kgCO2eq per functional unit) for the calculations are sourced from SIMAPRO/ Ecoinvent version 2.2.
The goal of these calculations is to estimate, and thus provide an overview of the materials and components in the ZEB residential model, which contribute the most to the embodied carbon dioxide emissions. The calculations are based on the principles of environmental assessment through life cycle analysis. It should be noted that in this first round of calculations, not all life cycle phases are included. In the next stage of the calculations, the model will be optimised and the impact on emissions recalculated accordingly
The passive house (PH) standard is seen as the future minimal requirement for buildings in Norway, where a specific definition has been developed (NS 3700). Nevertheless, the relation between this standard and air heating (AH) is not clear while both concepts are often associated. The present contribution investigates challenges for AH in terms of thermal dynamics (e.g. temperature distribution and control) as well as the feasibility of the AH concept. This is done using detailed dynamic simulations on a typical detached house typology. Results show some limitations of the AH concept in Nordic countries, as well as provide guidelines for the design procedure.
Design principles in Net-ZEB considers the local energy infrastructure as virtual storage leading to large amount of energy exchange with the grid. Nonetheless, with high Net-ZEB penetration scenarios, such exchange could compromise the effectiveness of Net- ZEB concept in a total energy infrastructure. As the current market trends, heat pumps along with photovoltaics are seen as an emerging energy supply solutions in Net-ZEB buildings, effectiveness of an all-electric Net-ZEB (that is using air-to-water heat pump with photovoltaic) is analysed. Two concrete control cases of energy storage (compared to reference case) to assess Net-ZEB ability to self-consume vs. grid empowerment are studied. Results shows that introduc tion of storage buffer in such concept leads to a flexibility of almost 6 % in self-consumption and 13 % in grid-impact factor and in-turn provide significant manoeuvring space to the demand-supply balance at the grid level.
The main aim of the work has been to do modeling and calculations of the energy use, embodied emission and the total CO2-emission for a typical Norwegian residential building. By doing this we try to reveal and study the main drivers for the CO2-emission, and also which performance is necessary for components and solutions in a Zero Emission Building according to the current Norwegian ZEBdefinition.
Wood stoves are attractive for the space-heating (SH) of passive houses. Nevertheless, there are still questions about their integration. Firstly, the power oversizing of the current stoves and their long operating time may lead to unacceptable overheating. Secondly, it is also unclear how one stove can ensure the thermal comfort in the entire building. The paper investigates these aspects using detailed dynamic simulations (TRNSYS) applied to a detached house in Belgium. An 8 kW stove is assumed to be representative of the lowest available powers in the market. Results confirm that a large power modulation is important to prevent overheating. Opening the internal doors, a high building thermal mass and a heat emission dominated by radiation also reduce the overheating risk, but to a smaller extent. Besides, a single stove cannot enforce the thermal comfort during design weather conditions: a peak-load system is then needed. Using more standard conditions, a Typical Meteorological Year (TMY), the stove can mainly perform the SH but it then requires the internal doors inside the building to be opened. The temperature distribution between rooms is in fact dominated by the architectonic properties. Finally, the emission and distribution efficiency of the stove is also investigated.
State-of-the-art wood stoves could be an attractive solution for the space heating of passive houses. The question of the integration of wood stoves in passive envelopes is rather new and still open, the main constraints being the power oversizing ant the heat distribution. The paper proposes a low-resolution simulation approach to provide an insight into the whole-year thermal comfort using a stove, and into the relative effect of the large number of physical parameters involved in the problem. In particular, a simple stove model is developed for detailed dynamic simulations in order to fairly represent the heat emission properties of small airtight stoves. As an example, the methodology is finally applied to a test case, here a typical detached passive house.
It is becoming conventional approach to evaluate the building envelop losses using detailed dynamic tools such as EnergyPlus, ESP-r and TRNSYS. However, the user-related loads (and their variations) in the building are usually oversimplified during performance evaluation of those buildings and associated HV AC systems. This paper presents a methodology to evaluate the performance of buildings and their energy supply systems while taking into account the user-related loads (non-HV AC & DHW) at individual household levels. For this purpose, a single family house (two different insulation cases) built in Oslo climate using an alternate duty air to water heat pump is used as a case study. The investigation shows that a large variation occurs in space heating needs for the same standard house when actual user loads are considered. The study also shows that the storage losses dominate the performance of total heat supply system in case of passive house insulation.