High-performance Houses Research Articles

Futures for electrochromic windows on high performance houses in arid, cold climates

This study investigates high performance electrochromic windows used on a passive house and residential dwelling to IECC 2021 (i.e., IECC dwelling). In the lab, the electrochromic film switches transmitted solar heat gain coefficient (SHGC) from 0.09 to 0.7 and visible transmittance from 0.15 to 0.82 with power consumption of 1.23 W/m2 during switching times less than 3 minutes. We extrapolate these results to a window assembly. Building energy models of the houses were evaluated in Santa Fe, New Mexico. A Monte Carlo analysis for 2020, 2040, 2060, and 2080 was conducted for Shared Socioeconomic Pathways 2-4.5, 3-7.0, and 5-8.5. Cases with and without the electrochromic windows and with and without electricity were used to determine energy use intensity and hours beyond thermal safety thresholds.The passive house showed 1.3-3.1% mean energy savings and the IECC dwelling 4.4-5.1% with electrochromic efficiency benefits growing into the future for both cases. Even so, overall savings decrease into the future for the passive house, due to growth in cooling load being dominant, conversely overall energy savings increase into the future for the IECC dwelling due to heating loads being dominant. For thermal resilience, the passive house exhibited a mean percent decrease of 0.02-0.31% hours in the extreme caution (i.e., > 32.2∘C, ≤ 39.4∘C) range while the IECC dwelling exhibited 0.38-4.38%. The study therefore shows that electrochromic windows will have smaller benefits for the passive house in comparison to the IECC dwelling. The relationship between electrochromic windows is shown to have a complex relationship between house efficiency and climate change by these results.

Development of electricity simulation model of urban houses and evaluating surplus electricity of photovoltaics (PV) considering housing stock transformation

The Japanese government is advocating for the introduction of decentralized renewable energy devices such as photovoltaics (PV) and high thermal performance houses in urban areas. Due to variations in housing stock among different urban areas, the implementation of these houses and devices would have diverse effects on the supply and demand sides, potentially leading to diverse overproduction of PV electricity, referred to as surplus electricity. Existing research focuses on increasing the utilization of surplus electricity and quantifying the surplus electricity from individual buildings at a regional scale. Considering the lack of research that quantifies surplus electricity through shared PVs under the urban-scale contextual changes (widespread introduction of high-performance houses). Therefore, this study aims to address this gap by utilizing an archetype house simulation model to simulate and compare two scenarios (with or without houses retrofitting) regarding electricity demand for each street-level area, maximum power and duration time of surplus electricity in areas where surplus electricity would occur in the target city Fukuoka in 2025. The results indicate that, under the current residential PV stock and existing introduction rates, the peak surplus power occurs around noon in May, approximately 396 out of 1051 areas in Fukuoka would generate surplus electricity during 2025. Houses retrofitting would increase the surplus electricity (include maximum power and duration time) in these areas. Additionally, this study identifies the residential characteristics of areas that generate surplus electricity, including construction year, household composition, and the proportion of detached houses, whether with retrofitting or not. The results suggest attention to surplus electricity increasing in areas with a high proportion of detached houses when considering houses retrofitting.

Influence of the occupant factor on the thermal quality of a high energy performance house type 80 eco-bat housing, Blida program, Algeria

This paper discusses the best way of energy management. It is an initiation for the improvement of the constructive system in Algeria. Within the framework of the ECO-BAT program, we take a unit from the 80 HEP housing units in Blida as a case study, on which we undertake in-situ measurements and the questionnaire for a subjective evaluation of the thermal environment of the dwellings and the level of awareness among the occupants. This work aims to test the feasibility of the energy solutions adopted for this system by verifying the winter thermal comfort as well as the energy consumed for heating. The solutions of this research will be the support of improvement recommendations for energy management programs in the future.

A Review of Housing Certification Standards with a Focus on Energy Efficiency

In addition to building codes and regulations, voluntary housing certification standards also play an important role in the energy efficiency of housing. Each of these standards was established in response to a set of specific demands for high performance housing. Consequently, the energy conservation technologies and design approach applicable could be very diverse and dynamic. This paper is aimed to provide a comprehensive review for the state-of-the art housing standards with a focus on energy efficiency. It was observed that these standards normally evaluate energy efficiency based on percentage savings of the design with energy conservation measures compared to a reference case. The net-zero energy balance between energy consumption and on-site energy generation is considered the highest level of performance. This paper examines if this approach is adequate and prompts future research in order to improve the effectiveness of housing standards in defining sustainable housing.

Multi-phase framework for optimization of thermal and daylight performance of residential buildings based on the combination of ventilation and window design

ABSTRACT The environmental design of residential buildings is an arduous process involving a large number of parameters and objectives . Additionally, with the development trend of high-performance housing around the world, its disadvantage – the risk of overheating – has begun to increase, which further shows the importance of comprehensive optimization of residential buildings. This study presents a highly targeted optimization framework for residential buildings based on the adjustment of window-related parameters coupled with various natural ventilation patterns. Multiple phases are carried out in this optimization framework to optimizes three objectives, i.e. energy consumption, thermal comfort, daylight environment simultaneously. Phase 1 applies various natural ventilation patterns to explore the improvement potential of ventilation patterns. Phase 2 implements a genetic algorithm to achieve the Pareto optimization of window-related parameters. Phase 3 filters more robust Pareto-optimal based on Multi-Criteria Decision-Making logic to meet the different needs of different skateboards and architectures. The innovation and scientific significance lie in parameters include both the building envelope elements and ventilation patterns, as well as highly targeted for residential building. The results show that natural ventilation effectively improves the potential for simultaneous optimization of multiple objectives, and the optimization framework can adapt to residential buildings with various envelope insulation performance.

A human-centred approach to smart housing

ABSTRACT Smart buildings are complex systems, yet architecture, engineering, and construction (AEC) professionals often perform their work without considering the human factors of building occupants. Traditionally, the AEC industry has employed a linear design and delivery approach. As buildings become smarter, the AEC industry must adapt. To maximize human well-being and the operational performance of smart buildings, an iterative, human-centred approach must be employed. The omission of human factors in the design and delivery of smart building systems risks misalignment between occupant-user needs and the AEC industry’s perception of occupant-user needs. This research proposes a human-centred approach to smart housing. The study employed a multi-phase, mixed-methods research design. Data were collected from 309 high performance housing units in the United States. Longitudinal energy use data, occupant surveys, and semi-structured interviews are the primary data inputs. Affinity diagramming was leveraged to categorize the qualitative data. The output of the affinity diagramming analysis and energy analysis led to the development of data-driven Personas that communicate smart housing user needs. While these data were gathered in the United States, researchers, practitioners, and policy-makers can leverage the human-centred approach presented in this paper toward the design of other human-centred buildings and infrastructure.

Identification of overheating in the top floors of energy-efficient multilevel dwellings

This study investigates summer indoor temperatures in energy-efficient multilevel houses built since 2010 in Adelaide to identify and define overheating during summer months. The method includes three steps: 1) calculating the number of days with top-floor maximum daily air temperature above 32 °C during four summers (December-February of 2011–2015); 2) calculating the frequency, integral and average of outdoor air temperature above 35 °C and the same parameters for top-floor temperature exceeded ground floor temperature for the naturally ventilated (NV) mode during eight summers (December-February of 2011–2018); and 3) correlation between ground floor temperature and outdoor sunshine hours as well as running mean outdoor temperature for NV mode during the same eight summers.Results showed the top-floor maximum daily air temperature was above 32 °C for 21% of the summer days for a mix of air-conditioned (AC) and NV modes. Overheating occurred in the top floors. Overheating occurs in low-performance energy-efficient houses about twice more often than high-performance energy-efficient houses. While the ground floors of high-performance houses matched the adaptive thermal comfort standard, the top floors exceeded the adaptive thermal comfort by overheating for 243 h, with 250 integral and intensity of 3.5 °C. Overheating in top floors lasts significantly longer than the outdoor high summer temperature. The paper also proposes novel parameters for evaluating the occurrence of overheating based on analysis of the data.

Viability of integrating Solar Water Heating systems into High Energy Performance housing in Algeria

In the framework of the new Algerian energy policy, we investigate in this contribution the energetic and the economic viability of the integration of Solar Water Heating (SWH) systems into High Energy Performance (HEP) housing in Algeria. The case studies are houses situated in four different locations each one representing a distinct Algerian climatic zone. In order to efficiently design the SWH systems to be installed, we use a simple method based on the determination of the optimum collector area that minimizes the costs of the installation via considering both economic factors and system parameters. The solar fraction, needed for this analysis, has been calculated using the F-Chart method with monthly meteorological data characterizing each region. The results revealed very promising high values of the solar fraction in almost all the studied regions and that an adequate funding policy will permit to establish a good balance between system performance and system design resulting in a higher competitiveness of solar energy against conventional energy.

Chifley Passive House: A Case Study in Energy Efficiency and Comfort

Abstract: Numerous mandatory energy efficiency building standards and rating systems have been developed globally. The International Passive House Standard is a voluntary alternative, but there is little data on the performance of houses built to this standard in Australia. One house in suburban Canberra demonstrates that the Passive House Standard can be used to build high-performance houses with predictable outcomes. Extreme energy efficiency and occupant comfort were key performance objectives in building the three-bedroom house. Like most energy efficient housing projects in Australia, the building was designed to take advantage of solar gain, thermal mass and cross flow ventilation, but what set this project and all Passive House projects apart was the careful attention to airtightness, mechanical ventilation, avoidance of thermal bridging and the use of energy modelling tools at the design stage. The result was a house that required virtually no heating in winter despite frosty -2°C mornings; no artificial cooling in summer despite 37°C days and; overall consumed 64% less energy than similar households in the same city. Energy consumption, temperature and CO2 levels have been monitored and confirm exceptional levels of comfort and indoor air quality. The total energy consumed was within 12% of predicted values thus supporting the effectiveness of the Passive House Standard.

Verification of an emerging LCA design tool through real life performance monitoring

Recent research has demonstrated that low-emission houses often underperform, consuming more energy than predicted by their designs. Life cycle assessments (LCA) have been employed to complement mandatory energy assessments, as they offer a more comprehensive evaluation of greenhouse gas (GHG) emissions over the building lifespan. This research monitored ten energy efficient Australian houses and recorded data about energy use and photovoltaic generation over 1 year. The houses were assessed with a relatively new LCA tool in addition to the Australian mandatory house energy assessment Nationwide House Energy Rating Scheme (NatHERS). The objective of this study was twofold: first, to evaluate the results of the assessment tools compared to actual house energy requirements and second, to understand how design, renewable energy, and occupancy can impact the overall GHG emissions of the houses. The results show that energy use is positively related to NatHERS ratings, but some of the high performance houses perform poorly and there was significant variation in energy use between houses with the same ratings. The LCA revealed that modern houses have higher embodied energy than older houses, while solar panels are not always used to their full potential. This paper attributes some of the variations between theoretical and actual energy use to construction issues and occupant practices.

Design and Application of Concrete Tiles Enhanced with Microencapsulated Phase-Change Material

AbstractPhase-change materials (PCMs) have a high heat of fusion compared to that of traditional material, and for this reason, they are able to store and release larger amounts of energy at their transition temperature. The inclusion of PCMs in buildings has attracted much interest worldwide because of their ability to reduce building energy demand and increase indoor comfort. This paper presents the development and testing results of a concrete tile system with microencapsulated PCMs. The concrete tiles were cast for use in a high-performance house built for the Solar Decathlon China 2013 competition. The paper shows that the addition of PCMs reduced the overall compressive and flexural strength properties of the concrete. A more than 25% decrease in compressive strength was observed with the addition of 20% PCM per volume of concrete. However, a significant improvement in the thermal properties of the concrete tile PCMs was measured. The thermal energy storage capability of the PCM-enhanced concrete ti...

Efficiency and operational behaviour of small-scale pellet boilers installed in residential buildings

Abstract Biomass-based heating and domestic hot water supply systems in residential buildings need optimised system design to maximise the boiler’s efficiency. Although the efficiency of pellet boilers is certified through standard laboratory tests, there is only little information available in the literature about their performance in field conditions. The aims of this study were to compare the laboratory and field performance of small scale pellet boilers, and to characterise the boilers’ operation in the field, finding the parameters which have the strongest influence on the efficiency. This research consisted in the extensive monitoring of five pellet boilers installed in residential buildings in Austria, including new and recently refurbished houses, as well as pre-fabricated, high performance houses. Different system configurations without buffer storage tank were monitored for one year, to determine annual and monthly efficiencies. Results showed that annual efficiencies ranged from 65% to 85%, thus evidencing a lower performance if compared to the 90–94% efficiencies certified by standard laboratory tests. Efficiencies were correlated to the boilers’ load factors and number of ignitions, leading to the development of modified efficiency curves, suitable to predict the boiler’s performance in field conditions.

Regulatory energy calculations versus real energy use in high-performance houses

How accurately can official energy performance calculations assess the real energy use in high-performance houses? This question was investigated by analysing 537 dwellings. Data on building characteristics and calculated performance from the Flemish Energy Performance of Buildings (EPB) database were complemented with data from energy utilities and surveys of inhabitants, their socio-demographic characteristics and user behaviours. While the real and theoretical energy uses were strongly correlated, the official calculation method overestimated the heating energy use of most houses while neglecting important electricity end uses. The prediction error varied strongly between individual cases. Two options within the calculation procedure had a significant impact on these prediction errors: the use of default values for the air tightness of the building envelope and the reported return temperature of the space heating system. The simplified calculation of net domestic hot water consumption and the real heating of the master bedrooms also affected prediction accuracy. However, extrapolations are hazardous due to the risk of selection and non-response biases implied by the approach and the need for further research into the causalities. Nonetheless, the findings stress the importance of accurate input data and realistic default values for calculation models used for high-performance buildings.

Modeling of an Indirect Solar Assisted Heat Pump System for a High Performance Residential House

The combination of solar thermal and heat pump systems as a single solar assisted heat pump (SAHP) system can significantly reduce residential energy consumption in Canada. As a part of Team Ontario's efforts to develop a high performance house for the U.S. Department of Energy's Solar Decathlon 2013 Competition, an integrated mechanical system (IMS) consisting of a SAHP was investigated. The system was designed to provide domestic hot water (DHW), space-heating, space-cooling, and dehumidification. The system included a cold and a hot thermal storage tanks and a heat pump to move energy from the low temperature reservoir to the hot reservoir. Solar thermal collectors supplied heat to the cold storage and operated at a higher efficiency due to the heat pump reducing the temperature of the collector working fluid. The combination of the heat pump and solar thermal collectors allows more heat to be harvested at a lower temperature, and then boosted to a suitable temperature for domestic use via the heat pump. The IMS and the building's energy loads were modeled using the TRNSYS simulation software. A parametric study was conducted to optimize the control, sizing, and configuration of the system. The simulation results suggested that the investigated system can achieve a free energy ratio (FER) of about 0.583 for the high performance house designed for the Ottawa climate.

Fire Performance Assessment of a Fiber Reinforced Polymer Wall Panel Used in a Single Family Dwelling

This paper describes a fire performance assessment of a sandwich panel selected as the primary material in a high-performance house developed for the 2013 China Solar Decathlon competition. The sandwich panel has fiber reinforced polymer skins and a foam plastic core. Evaluation of fire performance showed that the selected panel would not comply with U.S. building code requirements for a single-family dwelling without additional protection. However, the use of an intumescent fire protective coating, coupled with the installation of a residential fire sprinkler system, is shown to be effective in meeting the intent of the fire and life safety requirements of the International Residential Code. Fire testing shows that the application of an intumescent fire protective coating to the panels significantly decreases the heat release rate, the smoke production characteristics, and the extent of flame spread on the panels.

Daylighting in an atrium-type high performance house

Different lighting strategies for an atrium-type high performance house that was developed for the 2013 Solar Decathlon competition in Datong, China are discussed in this paper. Although daylighting may be abundant in an atrium, with large exposed window surfaces, such design is typically avoided in high-performance houses due to the poorer thermal performance of glazing compared to opaque building envelopes. However, advantages of the atrium design exist in different weather conditions and are investigated in this paper. Insights from a Solar Decathlon 2013 project with a central atrium and a high amount of glasses in the external envelope (80 square meters of glasses) are given. The house was designed considering weather of Datong and Worcester, Massachusetts (US). Simulation results obtained with Radiance and Daysim allow assessing different parameters such as the daylight autonomy index and the useful daylight index. The challenge of visual comfort for a house with such a great quantity of windows is realized considering different parameters related to the visual glare, including the instant and cumulative daylight glare probability indexes. These glare metrics are often inconsistent as the probability of glare was sometimes depending on the selected index. Different chances to have glare issues resulted using different indices. Finally, the influencing factors for blind adjustments in residential buildings are discussed, and according to these factors and to simulation results with several software, the design of the shading systems and their schedules are evaluated.

Net climatic impact of solid foam insulation produced with halocarbon and non-halocarbon blowing agents

The net climatic effect of increasing the amount of insulation in buildings through the use of halocarbon-blown foam insulation involves three factors: the greenhouse gas emissions associated with the energy used to make the insulation; the climatic impact of leakage of the halocarbon blowing agent from the insulation during its manufacture, use, and at the time of disposal; and the reduction in heating and/or cooling energy use and associated greenhouse gas emissions. Recent studies and assessments leave the impression that the use of halocarbon-blown foam insulation has a strong net positive impact on climate, with the reduction in heating-related emissions being 20–100 times greater than the CO 2-equivalent halocarbon emissions. This result applies only to the overall impact of rather modest levels of insulation applied to a pre-existing roof or wall with negligible thermal resistance. It is appropriate to consider the time required for heating-related emission savings to offset halocarbon and manufacturing emissions for the addition of successive increments of insulation—the marginal payback time. For typical blowing agent leakage rates and for insulation levels found in high-performance houses, marginal payback times can be in excess of 100 years using halocarbon blowing agents, but are only 10–50 years using non-halocarbon blowing agents. With a fixed thickness of insulation, the difference in heating energy savings using insulation with different blowing agents is generally only a few per cent, in spite of differences in thermal conductivity of up to 66%. The net savings in CO 2-equivalent emissions is larger using non-halocarbon blowing agents, with the relative benefit of using non-halocarbon blowing agents greater the greater the thermal resistance of the envelope element prior to adding foam insulation.

Enhanced energy conservation in houses through high performance design

Key design features of high performance houses are investigated for improving energy efficiency in cold climates. Reference dwellings with typical constructions and system designs are compared with high performance houses using the best technology available. The dwellings used for reference are a multi-family apartment building and a single-family detached house, designed according to a mix of Nordic building codes of 2001. The high performance houses designed fulfilled the target requirements of IEA Task 28, Sustainable Solar Housing. Simulations of the buildings are performed using the computer programme DEROB-LTH and results from simulations give the hourly space-heating demand and peak load of the buildings. A comparison of reference houses to high performance solutions shows that the space-heating demand can be reduced by up to 83% for single-family houses and by up to 85% for apartment buildings. The climate data used for all simulations is Stockholm, Sweden. The environmental effects in terms of CO 2 equivalent emissions and use of non-renewable primary energy are quantified for each building type and construction. The energy saving potential of high performance houses in cold climates is demonstrated.

Breaking the “heating barrier”: Learning from the first houses without conventional heating

When a house can be designed to require less than 10 W/m 2 of heating capacity to maintain 20 °C by −10 °C ambient conditions, a conventional heating system (i.e. a gas fired furnace, circulation pipes and radiators) can be omitted and total energy consumption drops to a small fraction of normal levels. The result is a drastic reduction in both operating costs and environmental impact. This performance has been achieved in numerous demonstration projects in Europe, including whole developments of detached and row houses as well as apartment buildings. The goal now is to penetrate the broad housing market. This is hindered by often higher construction costs. The challenge is, therefore, to better understand which design features and components contribute the most to achieving such high performance housing, and which measures can be omitted or substituted. Experience has led to a specific set of requirements which the building envelope and technical systems of a house must satisfy. However, these requirements must be fulfilled under different boundary conditions than those for conventional houses, making decisions less than obvious. Five building projects are presented here as examples of successful solutions and these are cross compared. Finally, an outlook is offered regarding what approaches and features will survive in this emerging, next generation of housing.

自然室温による日本各地の戸建住宅の熱性能評価に関する研究

This study proposed a evaluation method of the thermal performance of detached houses using natural room airtemperature. The numerical simulations were performed to clear the effects of techniques such as wall insulation, multiple glazing, south-facing large windows and air tightness of the house as well as summer solar shading and natural ventilation on the natural room air temperature. The scheme of high-performance houses that exceed the assumed criterion of the natural room air temperature were presented for 10 cities in Japan.