Residential Case Study Research Articles

Design Optimization of a Heat Thermal Storage Coupled with a Micro-CHP for a Residential Case Study

Energy efficiency is a key target of the European Union policy. The “Europe 2020 strategy” quantitative targets account an increase by 20% of the energy efficiency by the end of 2020. The attention to power sources optimization and energy waste reduction leads European Countries to develop subsidy strategies to drive the energy market towards efficiency enhancement. According to this trend, energy efficiency of residential buildings has significantly grown in Italy in the last years. Combined production of electric and thermal power is a notable example of efficiency enhancement awarded by the CAR (Cogenerazione ad Alto Rendimento) Italian subsidies system. In these circumstances, the optimization of the ensemble between power generators and thermal storages becomes crucial to satisfy in an efficient way thermal power requirement independently from electric power production. The purpose of this paper is to find the optimal power plant design of power generators and thermal storages in order to minimize daily management costs and environmental impact. The power plant layout in analysis consists in a micro-CHP (Combined Heat and Power) and an absorption chiller both coupled with respective thermal storages. Through this evaluation, it is possible to identify the optimal coupling of the devices as a function of the load requirements and understand the great influence of their sizing on the energy management benefits. The analysis is performed with reference to cold and warm thermal load required by a residential case study. The performance analysis takes place in representative days of different seasons and the results are extended on an annual base. The power request profiles are developed on the basis of literature data. The results are compared on an economic basis considering the NPV (Net Present Value) index, evaluated using as the benchmark a standard plant layout composed by a water boiler and an electric chiller.

Optimization of building envelope design for nZEBs in Mediterranean climate: Performance analysis of residential case study

Design criteria for a residential nZEB in Mediterranean climate are discussed. The integrated design procedure focuses on the problem of a large number of available building variants concerning the building envelope. The aim is to search the ones that minimize winter and summer energy demand without compromising thermal comfort.The adopted methodological approach combines the use of dynamic energy simulation tool (EnergyPlus), based on a one-dimensional conduction finite difference solution method, and a constrained multi-objective optimization algorithm. For four cities (Madrid, Nice, Naples, Athens), several passive strategies are compared: thermal properties of the building envelope, adoption of phase change materials with different melting temperatures, cool roof solutions, several window/wall ratio values, some external and internal shading systems. The results allow to evidence that it is difficult to understand the best trade-off between summer and winter performance, by assuring high standard of thermal comfort when the aim is to reach NZEB objectives in Mediterranean climate. However, some guidelines are indicated, starting from the discussed results.

A feasibility study of a residential photovoltaic system in Cameroon

This paper presents a feasibility study of stand-alone solar photovoltaic (PV) systems for the electrification of three residential case study buildings (T4, T5 and T6) in the capital city of Yaoundé, Cameroon. The system was sized taking into account the load of the buildings and the available energy from the sun. The power, area of PV modules and daily energy generated by the PV for T4, T5 and T6 were respectively determined as: 2103W, 14m2 and 9.8kWh/day; 3779W, 25.2m2 and 17.6kWh/day; and 2766W, 18.4m2 and 12.9kWh/day. The battery bank capacity, size of inverter and controller were respectively obtained as: 40,323Wh, 635W and 93A for T4; 72,433Wh, 795W and 156A for T5; and 53,017Wh, 826W and 114A for T6. The life cycle cost and annualized life cycle cost (ALCC) of the systems were respectively found to be: €15,714 and €1039 for T4; €27,227and €1800 for T5; and €20,006 and €1322 for T6. The average unit electricity cost for T4, T5 and T6 was respectively determined to be €0.52kWh−1, €0.50kWh−1 and €0.51kWh−1, higher than the unit cost of residential grid electricity in Cameroon.

The impact of future scenarios on building refurbishment strategies towards plus energy buildings

Buildings account for 40% of total global energy consumption. The International Energy Agency (IEA) and the European Commission (EC) are attempting to achieve an 80% reduction in global emissions by 2050. The objectives of this paper are to identify the refurbishment scenario with the lowest environmental impact using Life Cycle Assessment (LCA) and to assess the scenario’s robustness to future climate change scenarios using a sensitivity analysis. We applied and verified the proposed approach in a residential case study of a reference project located in Kapfernberg, Austria. The environmental assessment included two façade refurbishment proposals (minimum and high quality with respect to energy), onsite energy generation (using solar thermal collectors and photovoltaic (PV) panels), one renewable future energy mix and the effects of climate change according to the Austrian Panel on Climate Change (APCC). The environmental indicators used in the assessment were the cumulative energy demand non-renewable (CED n. ren.), global warming potential (GWP) and ecological scarcity (UBP) over building life cycles. The results indicated that a high-quality refurbishment of the thermal envelope with prefabricated façade elements, including solar thermal collectors and PV panels, represented the optimal refurbishment. In terms of the environmental indicators, the high-quality refurbishment scenario is always beneficial throughout the building’s life cycle. Additionally, the sensitivity analysis of the high-quality refurbishment scenario found an increasing production of surplus electricity with increasing PV area. This surplus of energy provides greater benefit in the short term with the current energy mix. Once the energy from the grid is shifted to renewable sources, the added benefit is decreased. Therefore, it is necessary to find an optimal balance between diminishing returns due to changes in the future energy mix and the financial investment made over the lifetime of the building, especially for plus energy buildings. However the findings from this specific case study need to be evaluated for other refurbishment cases, taking into account future local climate change and energy supply mix scenarios in other regions.

Public Intentions for Private Spaces: Exploring Architects’ Tactics to Shape Shared Space in Private-Led Residential Development

From the late 20th into the 21st centuries, the private market increasingly gained control from public authorities over strategic decisions affecting the quality of, and accessibility to, new urban development. This paper argues for architects to act more explicitly to promote greater open-ness and use-value, rather than more objectified and controlled exchange-value approaches to the public domain in private-led development. The paper analyses two London-based residential case studies and interviews with the architects about perceptions of, and approaches to, private-led development decision-making processes. It compares the individual practitioner’s experiences of architecture practice with explicit intentions to influence better quality shared city space, examining professional norms vis-à-vis commercial clients and wider society. The paper concludes that greater awareness of architects’ knowledge, skills, and a range of tactics to influence future shared environments can contribute to improved professional practice frameworks for more effective engagement in an increasingly globalised and privatised urban society.

Study and application of a regenerative Stirling cogeneration device based on biomass combustion

Fuelling micro-combined heat and power (micro-CHP) devices using renewable sources, such as biogas, can enhance the energy and environmental benefits associated with such devices. This paper presents a solution for increasing the electric efficiency of biogas-fed Stirling co-generators by recuperating the energy content of the combustion flue gas. When economically and energetically convenient for micro-CHP operation, the exhausts can be used to pre-heat fresh combustion air. It was assessed that, due to the introduction of a spiral gas–gas heat exchanger, whose main design parameters were identified, the electric efficiency of the Stirling unit can be raised to up to 22.5%. To determine the advantages of applying the system analysed over a traditional Stirling device, a specific algorithm for the optimal management of the micro-CHP unit was built and applied to a residential case study. The results demonstrate that the extra cost of the high-efficiency recuperator can be easily recovered in approximately two years of system operation, providing an additional advantage over a standard Stirling device in terms of primary energy consumption and an approximately 6% increase in economic savings.

On the Discourse of Energy as Material: Future Feedback Technologies and Directions for Experiencing Energy

Engineers are increasingly considering the social dimensions of energy use in the design of energy conservation technologies. This has led to design informed by ethnographic and theoretical inquiry on everyday energy practices and user-technology interactions that will in turn shape future practices and interactions. This paper contributes to the small but growing literature on real-time residential energy feedback displays that more closely examines how users experience such technologies. Survey responses from participants involved in a large-scale residential energy feedback monitoring case study are analyzed and contextualized into a set of positive and negative user “experiences.” The qualitative data derived from these responses add new insight on the social variables of user interaction with real-time feedback monitors that are of use to both the study of energy feedback monitoring and the design of future smart communities. Finally, an example is given of how these participant “experiences” are being put to the test in the design of a new energy feedback technology with implications for future ways of conceptualizing energy.

Prediction of future energy consumption reduction using GRC envelope optimization for residential buildings in Egypt

The recent IPCC reports and conferences drawn attention for the increased likelihood that unexpected climate events and changes might happen especially after reaching the 400ppm CO2 limit. This concept is getting more scientific understanding as “most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG concentrations”. Therefore, current practice of construction industry in Egypt as a mid-latitude region needs to consider passive architectural design for residential buildings as a crucial strategy for climate change mitigation. To achieve this, building envelope optimization is investigated in this paper both in the present time climate conditions and in the future scenarios as well. Two residential case studies were simulated by Design Builder using morphing methodology with the application of different Glass fibre Reinforced Cement, GRC, walls’ compositions in comparison to traditional walls in three Egyptian climatic zones. Both buildings showed gradual energy consumption reduction using the 10 and 12cm GRC-foam sandwich respectively showed an increase by time towards the year 2080. These reductions were considerable in the hot arid and semi hot arid zones rather than in the moderate zone.

Renovate for profit: New Zealand residential case study

PurposeThe primary purpose of this paper is to test an appropriate methodology for quantifying a return to residential property homeowners who were committed to make improvements to their homes prior to placing on the market for sale.Design/methodology/approachThis is a pilot study where empirical data were collected via two survey instruments from nine homeowners within the Horowhenua/Manawatu region of New Zealand. Market values of the properties before and after home improvement were assessed using a variety of market value measures including a valuation by a registered valuer, property owner's assessment and sale price.FindingsThe findings reveal that both the registered valuations and the property owner's assessment of expected sale price was within the range ±8 per cent of the final sale price. Seven of the nine houses included in this pilot study showed a positive return on time and money invested in minor home improvements.Research limitations/implicationsLimitations relate to the dated data, small sample size and geographical spread of the sample. The time and cost required to gather home improvement activity data is another limitation.Practical implicationsPotential exists for the model developed in this paper to be replicated internationally. This paper supports the view that homeowners who are actively involved in the real estate market have an accurate assessment of the value of their own homes. Improvements increase the quality and condition of existing residential housing stocks. Minor improvements are often overlooked due to the cost of gathering data. This paper encourages further studies of minor improvement expenditure on residential property.Originality/valueThis paper adds to the body of renovation literature as the data collection was conducted at the time improvements were being made, thus reducing response errors. The inclusion of comprehensive valuation reports by registered valuers increased the reliability of market value assessments. Research in this area is useful to provide greater understanding of the benefits of minor improvement expenditure.

Critical Concerns of Production Control System on Projects with Labor Constraints: Lessons from a Residential Case Study

Labor constraints and schedule pressures are common in periods of high market growth. Such conditions can have a significant impact on project performance. However, the extent to which such conditions impact the project depends on the effectiveness of the production control system. This case study analyzes the performance problems on a large residential project with significant labor constraints. The case first describes how the combination of labor shortage, high workload, and quality problems caused extensive workflow disruptions and schedule delays. Then, the analysis discusses why the production control system (the way the work assignments are planned, coordinated, and released for execution) failed to effectively manage these problems. The case is based on data from nine single-family houses in a large residential development. To evaluate the production control system, the authors used lean construction metrics and collected detailed data on the activities completed every week, the activities that we...

Local food production in home gardens: measuring on-site sustainability potential of residential development

Local food production is an integrated pathway to achieving a sustainable food future, appropriate urban ecosystem maintenance and meaningful environmental impact reduction. Current urban food production policies have demonstrated the sustainability importance of growing food locally. This paper analyses local vegetable productivities associated with available productive land areas as home gardens in low, medium and high density residential urban forms using aerial photographs, spatial ArcGIS and mathematical methods. It compares the food production potential of a household in five different residential urban form case studies from the Auckland Region, New Zealand. Potential annual household savings are estimated as Land Area Equivalents (LEQs) in hectares using ecological footprint conversion methods. The case studies were compared to determine the most 'food efficient' urban form considering average and maximum production scenarios. Outcomes indicate that community behaviour change and appropriate policy measures are critical for the uptake of local food production in home gardens.

Metrics of Local Environmental Sustainability: A Case Study in Auckland, New Zealand

Environmental impacts, in addition to economic, social and cultural drivers, have significant implications in the evolution of more sustainable urban forms. This paper presents the results of calculating potential local environmental sustainability using ecological footprint techniques in terms of five main aspects—domestic energy; transportation; vegetation cover; food; waste—for five residential urban form case studies in Auckland, New Zealand. This quantitative study formulates a comprehensive methodology for measuring comparative sustainability performances and identifies important residential urban form descriptors. As measured in this research, low-density urban forms may have more potential to be sustainable compared with other compact urban forms which may require a change of behavioural patterns for the residents.

Forming a joint venture with an institutional partner: a residential property case study

AbstractThe housing market in the UK has become increasingly polarised between the extremes of affordable housing and outright home ownership. This piece summarises the work done to structure institutional investments exploiting the wide gap in the housing market between these two extremes. The examples used are based on structures typical of those employed to date. Copyright © 2002 Henry Stewart Publications

EARTH COVERED: LOW, LIFE-CYCLE-COST HOUSING

SUMMARY The terms used to describe earth-contact structures are defined, and the advantages and disadvantages listed. Comparisons are made between the primary and secondary energy content of average brick and earth-covered dwellings; the reduced life-cycle costs of earth-covered homes are discussed. A New South Wales (N.S.W.) earth-covered residential Case Study is presented and post-occupation performance results considered.