Systems In Residential Buildings Research Articles

Performance evaluation of CO2-based ventilation control to reduce CO2 concentration and condensation risk in residential buildings

As the airtightness of a building envelope gets higher to achieve energy efficiency, the necessity of appropriate ventilation for residential buildings is continually increasing. Many residential buildings are equipped with energy recovery ventilators (ERV) for energy-efficient ventilation; however, the ERVs are usually operated by occupants' manual control, which often leads to insufficient or unnecessary ventilation. Because it is difficult to operate an ERV during nighttime, when occupants cannot control the system, a residential building can suffer from poor indoor air quality and increasing condensation risks. Herein, a CO2-based ventilation control strategy was implemented in an existing ERV system for residential buildings. Considering that most ERV systems operate with a central control, the appropriate CO2 sensor location (or representative room) was investigated in a mock-up residential building. Comparative experiments were conducted to evaluate the control performances in terms of indoor air quality (CO2 control performance) and fan energy consumption. Experimental results showed that a living-room-based control can maintain an overall CO2 concentration in the entire space at acceptable levels. It was also shown that a living-room-based control resulted in reduced ventilation energy if the CO2 dispersed through open bedroom doors. The CO2-based ventilation control was modified to mitigate the condensation risk while minimizing the possibility of fan noise or cold draught. Through mock-up experiments on a modified CO2-based ventilation control, it was shown that CO2 concentrations can be maintained at acceptable levels and condensation risks can be mitigated even when the outdoor temperature decreases to −15 °C.

Analytic Hierarchy Process & Multi Attribute Utility Theory Based Approach for the Selection of Lighting Systems in Residential Buildings: A Case Study

This paper presents an approach developed for selecting lighting systems in residential buildings using an Analytic Hierarchy Process (AHP) and the Multi Criteria Decision Making Technique (MCDMT). The developed approach considers four selection criteria of lighting systems: life-cycle cost, illumination, environmental performance, and life-span. The criteria of selection, along with the most widely used lighting systems in residential buildings, were determined through questionnaire surveys with suppliers, maintenance managers, and lighting experts. The Analytic Hierarchy Process and Multi Attribute Utility Theory were utilized to assess the significant influence of the identified main and sub-criteria on the selection process, from the design point of view. The developed approach was tested on a real case project in selecting the lighting system for aresidential building in Saudi Arabia. The obtained results show that the life-cycle cost and illumination proprieties, followed by the service life were found to be the most influential measures in the selection process. The results also show that Light-Emitting Diode(LED) lighting systems prove to bear the highest initial cost while sustaining the best overall performance.

Clustering a building stock towards representative buildings in the context of air-conditioning electricity demand flexibility

Energy modelling for the prediction of energy use in buildings, especially under novel energy management strategies, is of great importance. In buildings there are several flexible electrical loads which can be shifted in time such as thermostatically controllable loads. The main novelty of this paper is to apply an aggregation method to effectively characterize the electrical energy demand of air-conditioning (AC) systems in residential buildings under flexible operation during demand response and demand shaping programs. The method is based on clustering techniques to aggregate a large and diverse building stock of residential buildings to a smaller, representative ensemble of buildings. The methodology is tested against a detailed simulation model of building stocks in Houston, New York and Los Angeles. Results show good agreement between the energy demand predicted by the aggregated model and by the full model during normal operation (normalized mean absolute error, NMAE, below 10%), even with a small number of clusters (sample size of 1%). During flexible operation, the NMAE rises (around 20%) and a higher number of representative buildings become necessary (sample size at least 10%). Multiple cases for the input data series were considered, namely by varying the time resolution of the input data and the type of input data. These characteristics of the input time series data are shown to play a crucial role in the aggregation performance. The aggregated model showed lower NMAE compared to the original model when clustering is based on a hybrid signal resolved at 60-minute time intervals, which is a combination of the electricity demand profile and AC modulation level.

Design Optimization of a Small-Scale Polygeneration Energy System in Different Climate Zones in Iran

Design and performance of polygeneration energy systems are highly influenced by several variables, including the climate zone, which can affect the load profile as well as the availability of renewable energy sources. To investigate the effects, in this study, the design of a polygeneration system for identical residential buildings that are located in three different climate zones in Iran has been investigated. To perform the study, a model has previously developed by the author is used. The performance of the polygeneration system in terms of energy, economy and environment were compared to each other. The results show significant energetic and environmental benefits of the implementation of polygeneration systems in Iran, especially in the building that is located in a hot climate, with a high cooling demand and a low heating demand. Optimal polygeneration system for an identical building has achieved a 27% carbon dioxide emission reduction in the cold climate, while this value is around 41% in the hot climate. However, when considering the price of electricity and gas in the current energy market in Iran, none of the systems are feasible and financial support mechanisms or other incentives are required to promote the application of decentralized polygeneration energy systems.

INVESTIGATION OF THE POSSIBILITY OF USING A VORTEX HEAT GENERATOR IN HEAT SUPPLY SYSTEMS FOR RESIDENTIAL, INDUSTRIAL AND PUBLIC BUILDINGS

In a number of foreign countries, vortex heat generators have become widespread in decentralized heat supply systems. For Belarus, vortex heat generators are quite new sources of heat supply. The article considers the possibility of using vortex heat generators for heat supply systems for residential, public and industrial buildings. Vortex heat generators are based on the principle of cavitation in a turbulent water flow. For many devices cavitation is not desirable, but in a vortex heat generator it is used as a favorable phenomenon. The authors carried out a series of full-scale experiments to determine the efficiency of the “VTG-2.2” vortex heat generator when different operating modes were applied. The performance of the vortex heat generator can be estimated by the energy conversion factor. Energy conversion factor is the ratio of the amount of thermal energy that a vortex heat generator generates to the amount of electrical energy consumed. Experiments conducted in a number of research organizations (including the National Academy of Sciences of Ukraine and MPEI) have demonstrated that energy conversion factor can exceed 1. The authors conducted experimental tests with the use of an experimental installation simulating a heat supply system. According to the obtained experimental data, the energy conversion coefficients for each mode were calculated. The constructed graphical dependencies clearly demonstrate that, with increasing rotational speed of the vortex heat generator, the efficiency of its use increases. The highest energy conversion factor value was 61.1 % with a rotation frequency of 40 Hz. It was also found that with increasing the rotational speed of the vortex heat generator, a significant increase in noise and vibration occurs.

The optimization of light-wells with integrating daylight and stack natural ventilation systems in deep-plan residential buildings: A case study of Tehran

Simultaneous access to fresh air and daylight is one of the main problems in deep-plan buildings, causing increasing energy consumption for artificial lighting and mechanical ventilation. The proper design of light-wells as an integrated system to simultaneously provide daylighting and natural ventilation is the main topic of this research. In this study, a pattern for horizontal and vertical cross-sectional form of light-wells has been suggested for better daylighting and stack natural ventilation performance in connected rooms to light-wells. This suggested pattern of light-well can be used in future projects, located in different places with similar climatic conditions. Furthermore, daylighting and natural ventilation performance in different types of light-wells have been evaluated. The main tool of this research is computer simulation using Energy-Plus, Design Builder and Daysim simulation programs. Results show that the square light-well with 4 × 4 m minimum dimensions and the rectangular light well with 3 × 4 m dimensions can provide adequate ventilation rate and annual illuminance to the rooms connected to the light-well, up to 4 floors under the roof. Nevertheless, the air velocity and airflow pattern inside these rooms are not desirable for cooling by natural ventilation trough the light-well. Also, the quality of ventilated air in rooms connected to light-wells is low because the inlet air to upper floors comes from the outlet air from the lower floor. Considering these results, a revised light-well has been suggested for better daylighting and stack natural ventilation performance with some changes in the horizontal and vertical cross-sectional form.

Optimisation of Heat Loss through Ventilation for Residential Buildings

This study presents the results of research on heat loss from various types of residential buildings through ventilation systems. Experimental research was done to analyse the effectiveness of ventilation systems of different types and determine the parameters of air discharged via the ventilation ducts. A model of heat loss from the discharge of exhaust air outside through air ducts has since been developed. Experiments were conducted on three experimental systems of building ventilation: gravitational, mechanical, and supply-exhaust ventilation systems with heat recovery. The proposed model dependencies were used to chart the daily fluctuations of the optimum multiplicity of air exchange for precise control of the parameters of mechanical ventilation systems in residential buildings. This study proves that natural ventilation in residential buildings fulfils its function only by increasing the air flow into the building, and that this incurs significant heat loss from buildings during the heating season.

Motivational Psychology Driven AC Management Scheme: A Responsive Design Approach

Global warming, and the resultant climate change, has become an urgent global issue. One potential partial solution to this problem and the focus of this paper is to design energy management mechanisms for buildings that encourage users’ acceptance of the technology for increased environmental sustainability. Particularly, this paper focuses on the design of an energy management technique for the air-conditioning (AC) systems in residential buildings that considers users’ views on how they use such technology. Note that while a large number of energy management mechanisms are available in the literature for ACs, most of these studies, however, do not consider how well the users may accept their use in the building. To address this issue, this paper first synthesizes some motivational psychology literature to understand users’ attitudes toward adopting such management techniques for the ACs within the building. Then, the obtained insights from various motivational models are incorporated into the design of an energy management scheme that encourages consumers to accept the technology that reduces electricity consumption, the cost of electricity, peak power from the grid; and the generation of CO2 in the residential building. Finally, some experimental results are provided to illustrate how the designed energy management mechanism validates the motivational psychology models in terms of providing various benefits to the users, and thus shows the potential of being accepted by them.

Optimization of the proton exchange membrane fuel cell hybrid power system for residential buildings

A real-time optimization (RTO) strategy to find the optimal value of the fuel flow rate of a Fuel Cell Hybrid Power System (FCHPS) for residential buildings is proposed here, which is shortly named as Air_LFW-RTO strategy due to the use of Load-Following (LFW) technique to control the air flow. The optimization strategy uses the Global Extremum Seeking (GES) algorithm to adjust the fuel flow rate and harvest the FC power by using two GES control schemes. The performance obtained with Air_LFW-RTO strategy proposed herein is shown compared to Static Feed-Forward RTO strategy, where both fueling rates are controlled by the FC current. The performance have been estimated for 8 kW residential building based on following indicators: the fuel consumption efficiency, the FC system efficiency, and the fuel economy during a variable load demand. The fuel consumption efficiency and the energy efficiency could increase with more than 11.47 W/lpm and 2.13% for a FCHPS under 8 kW constant load. The fuel economy could be up to 263 lpm for a FCHPS under variable load cycle using the Air_LFW-RTO strategy.

A Concept of Value and Sustainable Performance On Affordable High-Rise Residential Decision

The need of residential space for low-income people has to be facilitated in urban spatial planning. Because of people will find affordable settlements in the suburbs so their daily mobility will cause congestion. In addition, the inadequate need for a place for low-income households will result in the proliferation of slums in the middle of the city. The goal of this research is to develop an optimal model in generating affordable high-rise residential design performance to improve the environmental quality and sustainability of urban spatial. The object study is a public housing as an affordable housing and formal settlement. When the cost of energy rises and availability decreasing, the need to provided energy-efficient design become more important. It is difficult to quantify and qualify the importance of values. This paper presents value-based decision to select energy system in an affordable high-rise residential building. Criteria for evaluating value are initial cost, life cycle cost, collaborative function, sustainable function, and integrative function. Model formulates, and its implementation based on application of satisficing option on multi criteria decision-making. Commencing at the design and planning stage, the technical, social, and economic sustainability of building energy needs to be considered.

Analysis of the use for Fire Protection Water Supply Systems in public utility buildings and residential buildings

Regulation of the Minister of Interior and Administration of 7 June 2010 on the fire protection of buildings, other construction objects and areas, presents a number of requirements that must be met by public buildings and residential buildings requirements, among others, for fire-fighting water supply installations. The article presents an analysis of current requirements for water supply installations in public buildings and residential buildings included in Polish legal acts. In addition, statistical data on the size of the fire are presented and real water consumption in the activities of fire protection units during events. These data were obtained from the SWD PSP program, which is the basic tool for supporting the actions of rescue and fire-fighting units. It turns out that for the objects in question statistically the largest amount of fires are small fires, where relatively little water is used. On the basis of the comparison of the actual water consumption needed to extinguish the fire by the fire department with the requirements in force in relation to the analyzed buildings, too restrictive requirements for these facilities were noticed. Appropriate efficiency of the external hydrant network ensures the possibility of carrying out extinguishing activities. In connection with the above, one should consider the legitimacy of applying high requirements for the efficiency of fire protection installations in facilities.

Electricity storage compared to net metering in residential PV applications

The installation of PV systems in residential buildings has seen a dramatic increase in the last decade thanks to national policies like Feed in Tariff and Net Metering. Several users are now needing to increase their share of self-consumption to optimize the profits from their systems. Energy storage systems are entering the market in last years, claiming to provide an interesting upgrade for existing PV systems. In a broader perspective, energy storage systems will have a significant impact on the entire energy production and conversion processes. The aim of this paper is to present an analysis of the energetic and economic performance of an electricity storage system, compared with the net metering scheme, which is an effective economic support for residential PV systems in different countries. This research work is based on the Italian market as a case study, to perform a detailed analysis on the net metering scheme. Multiple parameters are considered into the calculation, including the location, the PV size, the storage size and a range of installation costs. The results highlight the main issues related to this technology, both from an energetic and economic point of view. While the economic sustainability is currently far from being reached, also the electricity losses generated in the storage system appear to be a significant disadvantage.

Analysis of the systems of ventilation of residential houses of Ukraine and Estonia

Abstract The most common ventilation system in residential buildings in Ukraine is natural ventilation. In recent years, due to increased tightness of structures, an increase in the content of synthetic finishing materials in them, the quality of microclimate parameters deteriorated. One of the measures to improve the parameters of indoor air in residential buildings is the use of mechanical inflow and exhaust ventilation system. In this article the regulatory documents concerning the design of ventilation systems in Ukraine and Estonia and the requirements for air exchange in residential buildings are considered. It is established that the existing normative documents in Ukraine are analogous to European norms, which allow design the system of ventilation of residential buildings according to European standards. However, the basis for the design of ventilation systems in Ukraine is the national standards, in which mechanical ventilation, unfortunately, is provided only for the design of high-rise buildings. To maintain acceptable microclimate parameters in residential buildings, it is advisable for designers to apply the requirements for designing ventilation systems in accordance with European standards.

Design and optimization of zero-energy-consumption based solar energy residential building systems

Energy consumption of residential buildings has grown fast in recent years, thus raising a challenge on zero energy residential building (ZERB) systems, which aim at substantially reducing energy consumption of residential buildings. Thus, how to facilitate ZERB has become a hot but difficult topic. In the paper, we put forward the overall design principle of ZERB based on analysis of the systems’ energy demand. In particular, the architecture for both schematic design and passive technology is optimized and both energy simulation analysis and energy balancing analysis are implemented, followed by committing the selection of high-efficiency appliance and renewable energy sources for ZERB residential building. In addition, Chinese classical residential building has been investigated in the proposed case, in which several critical aspects such as building optimization, passive design, PV panel and HVAC system integrated with solar water heater, Phase change materials, natural ventilation, etc., have been taken into consideration.

Distributed Secondary Level Control for Energy Storage Management in DC Microgrids

DC microgrids have been known to be a promising solution for improving renewable energy integration with electrical grid and enhancing the system’s overall energy efficiency. A key component of this microgrid is the energy storage system, which besides smoothing the intermittent behavior of renewable sources, also allows intentional islanding and the execution of optimization routines to improve the microgrid performance. Assuming that storage systems in commercial and residential buildings will mostly be composed of multiple storage units, an energy storage management system, which provides charge/discharge monitoring and state-of-charge (SOC) equalization, is needed to prevent overcharging the units or their uneven use, which can lead to faster deterioration of battery banks. This paper proposes an energy storage management system based on distributed secondary level control, which promotes charge/discharge control and provides SOC equalization simultaneously. The SOC imbalance compensation alters the energy storage unit virtual droop resistance according to the difference between the unit SOC and the microgrid average SOC, thus the compensation intensity is dependent on the imbalance level being suitable to be employed in dc bus signaling controlled microgrids.

건축물 설비시스템 에너지 효율화 대안의 에너지 성능평가 및 경제성 분석에 관한 연구

Various researches are being carried out and various policies are being actively implemented for energy efficiency of buildings. Therefore, the participation in the related parties is actively required for the energy efficiency of the building. However, the biggest problem of the energy efficiency of the building is lack of information and it is required to construct a database on energy efficiency information. Therefore, this study analyzed the application status of the installation system in non residential buildings, constructed the EEM and the economic DB which can be applied and evaluated by using ECO2, which satisfies domestic legal standards. In addition, the target building was selected and the optimal EEM of the target building was derived by applying the EEM and the economic DB constructed through the EEM derivation process.

Field Measurement and Evaluation of the Passive and Active Solar Heating Systems for Residential Building Based on the Qinghai-Tibetan Plateau Case

Passive and active solar heating systems have drawn much attention and are widely used in residence buildings in the Qinghai-Tibetan plateau due to its high radiation intensity. In fact, there is still lack of quantitative evaluation of the passive and active heating effect, especially for residential building in the Qinghai-Tibetan plateau areas. In this study, three kinds of heating strategies, including reference condition, passive solar heating condition and active solar heating condition, were tested in one demonstration residential building. The hourly air temperatures of each room under different conditions were obtained and analyzed. The results show the indoor air temperature in the living room and bedrooms (core zones) was much higher than that of other rooms under both passive and active solar heating conditions. In addition, the heating effect with different strategies for core zones of the building was evaluated by the ratio of indoor and outdoor degree hour, which indicates that solar heating could effectively reduce the traditional energy consumption and improve the indoor thermal environment. The passive solar heating could undertake 49.8% degree hours for heating under an evaluation criterion of 14 °C and the active solar heating could undertake 75% degree hours for heating under evaluation criterion of 18 °C, which indicated that solar heating could effectively reduce the traditional energy consumption and improve the indoor thermal environment in this area. These findings could provide reference for the design and application of solar heating in similar climate areas.

Application of a multi-function solar-heat pump system in residential buildings

In this study, a multi-function solar photovoltaic/thermal (PV/T)-heat pump system was designed and established to supply energy for residential buildings. The system could realize different functions by operating in different modes, such as heating in winter, cooling in summer, domestic water heating for a whole year, and part of household electricity demand. System performance was experimentally investigated. Results showed that the average overall efficiency of PV/T collector was more than 50% for PV/T water heating mode when solar irradiance was sufficient, thereby indicating the good performance of the PV/T collector. Under experimental conditions, the coefficients of performance (COPs) of PV/T-WSHP heating mode and PV/T-W&ASHP heating mode were 3.18 and 2.53, which were much higher than the COP of ASHP heating mode with 2.23. The difference was attributed to that the addition of solar energy could improve evaporating temperature of heat pump system. Therefore, different operating modes could be activated, thereby realizing the maximum possible energy conservation. In conclusion, the system could fully utilize solar energy and realize advantageous complementarities between solar energy and heat pump by cascade energy utilization. The data and analysis could provide a reference for the combination form between solar PV/T system and different heat pump systems.

Modeling, simulation and dynamic control of solar assisted ground source heat pump to provide heating load and DHW

Having great resources of fossil fuels in Iran and ease of access to them inhibits utilization of renewable energies, especially in large scales. In spite of great sources of fossil fuels, Sistan province in the southeast of Iran has no gas pipelines yet and people sometimes use gas cylinders or oil products for heating of their houses. This paper aims to propose a sustainable renewable energy system to provide heating systems for residential buildings as well as domestic hot water (DHW). Five different combinations of solar assisted ground source heat pump (SAGSHP) are simulated for a residential building in the city of Zahedan, Iran. Modeling, simulation, and operation controlling have been performed in TRNSYS software and the coefficient of performance (COP), electrical power consumption of the GSHP, soil temperature, as well as building and domestic hot water temperatures for 10 years of operation have been obtained and compared. It is obtained that a 12kW GSHP with the assisted flat solar collectors can supply space heating demand and DHW for the building throughout the winter. The maximum and minimum annual mean COP values are 3.75 and 3.52, respectively. In the best scenario for the system assisted with the solar collector, the energy consumption diminishes 8.7% compared to GSHP standalone system.

Efecto de amortiguamiento térmico de una barrera verde de Arundo donax como elemento de bioclimatización en edificios

Entre los principales impactos ambientales derivados de la operación de edificios habitacionales está la generación de gases de efecto invernadero resultante del consumo eléctrico de sistemas de climatización. El uso de sistemas de vegetación representa una alternativa para disminuir dicho consumo energético. Las barreras verdes son sistemas de vegetación empleados como protección contra el viento, aunque recientemente se ha explorado su uso como sistemas de amortiguación acústica. En este trabajo se analiza su posible aplicación como sistemas de aislamiento térmico para edificios. En específico, se reporta el comportamiento de una barrera verde de Arundo donax como elemento de bioclimatización. Los resultados se analizan a partir de las temperaturas medidas en el interior y exterior de edificios prototipo, en función de la presencia de una barrera verde. Adicionalmente se determinó la traspiración del Arundo donax en condiciones ambientales extremas.