scholarly journals Influence of Building Air Tightness on Energy Consumption of Ventilation System in Nearly Zero Energy Residential Buildings

2019 ◽  
Vol 111 ◽  
pp. 03074
Author(s):  
Wei Liu ◽  
Zhen Yu ◽  
Jianlin Wu ◽  
Huai Li ◽  
Caifeng Gao ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Control Strategy ◽  
Energy Recovery ◽  
Residential Buildings ◽  
Ventilation System ◽  
Design Parameters ◽  
System Control ◽  
Recovery Efficiency ◽  
Zero Energy ◽  
Air Tightness

Building air tightness increased quickly in recent years as nearly zero energy buildings concept gradually drawn more attentions from the industry. Ventilation system plays an important role for the indoor air quality control in residential buildings with good air tightness. The energy consumption of the ventilation system is a significant part of the overall energy consumption of low energy residential building. The influence of the building air tightness on the energy consumption of ventilation system was not addressed sufficiently in previous studies. This paper analyses the quantitative relations between building air tightness, energy recovery efficiency and ventilation system control strategy. A mathematical model of the heating and cooling energy consumption in residential buildings is proposed, which takes building air tightness, energy recovery efficiency and control strategy of ventilation system as major input parameters. Equivalent COP of ventilation energy recovery system is proposed as an energy efficiency index of the ventilation system. It can be used as a criterion to decide the optimal design parameters of nearly zero residential buildings in different climate conditions.

scholarly journals Humidity-Sensitive Demand-Controlled Ventilation Applied to Multi-Unit Residential Building – Performance and Energy Consumption in Dfb Continental Climate

2020 ◽  
Author(s):  
Jerzy Sowa ◽  
Maciej Mijakowski
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Energy Savings ◽  
Residential Buildings ◽  
Ventilation System ◽  
Residential Building ◽  
Primary Energy ◽  
Controlled Ventilation ◽  
Demand Controlled Ventilation ◽  
Continental Climate

A humidity-sensitive demand-controlled ventilation system is known for many years. It has been developed and commonly applied in regions with an oceanic climate. Some attempts were made to introduce this solution in Poland in a much severe continental climate. The article evaluates this system's performance and energy consumption applied in an 8-floor multi-unit residential building, virtual reference building described by the National Energy Conservation Agency NAPE, Poland. The simulations using the computer program CONTAM were performed for the whole hating season for Warsaw's climate. Besides passive stack ventilation that worked as a reference, two versions of humidity-sensitive demand-controlled ventilation were checked. The difference between them lies in applying the additional roof fans that convert the system to hybrid. The study confirmed that the application of demand-controlled ventilation in multi-unit residential buildings in a continental climate with warm summer (Dfb) leads to significant energy savings. However, the efforts to ensure acceptable indoor air quality require hybrid ventilation, which reduces the energy benefits. It is especially visible when primary energy use is analyzed.

scholarly journals Photovoltaic systems – types of installations, materials, monitoring and modeling - review

2020 ◽  
pp. 40-49 ◽  
Author(s):  
Angelika Anduła ◽  
Dariusz Heim
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Residential Buildings ◽  
Future Research ◽  
Photovoltaic Systems ◽  
Zero Energy ◽  
Thermal Systems ◽  
Photovoltaic Panels ◽  
Common Solution

Photovoltaic systems have become a common solution for, both small residential buildings as well as large service buildings. When buildings are being designed, it is important to focus on the aspect of the object’s energy efficiency as lowering the energy consumption of a given facility is crucial. The article discusses the use of photovoltaic panels such as so-called BAPV (Building Applied Photovoltaics) and BIPV (Building Installed Photovoltaics) installations as well as photovoltaic thermal systems (PV/T), which generate both electricity and heat. The role of PV installation in so-called zero energy buildings and proposals for future research and solutions are also discussed.

Improved Design Parameters for a Liquid Desiccant Dehumidifier in Confined Spaces

Solar Energy ◽  
2005 ◽  
Author(s):  
D. Dong ◽  
M. Liu
Keyword(s):  
Energy Consumption ◽  
Ventilation System ◽  
Exhaust System ◽  
Design Parameters ◽  
Confined Space ◽  
Confined Spaces ◽  
Exhaust Ventilation ◽  
Moisture Condensation ◽  
Improved Design ◽  
Control Application

Investigations of a desiccant dehumidifier system have been performed for humidity control application in confined spaces. A previous study revealed that the base dehumidifier system can reduce moisture condensation by 22% over a conventional exhaust ventilation system. The current study aims to develop improved design requirements for a desiccant dehumidifier. The energy consumption of an exhaust ventilation system and an improved dehumidifier system was compared. To investigate the improved desiccant dehumidification system, numerical simulations were conducted and an objective function was established. This paper presents simulated results for an existing desiccant dehumidification system and an improved system, in which improved parameters are used. Use of the improved design parameters can reduce moisture condensation by 26.6% over a base dehumidifier system and shorten the dehumidifier performance period by 14%. Energy consumption with the sole use of an exhaust system is compared with that of the improved dehumidifier system under the same conditions. The results show that energy consumption can be substantially reduced, by 63%, in the improved dehumidifier system with the same amount of moisture condensation on surfaces of the confined space.

The applicability of nearly/net zero energy residential buildings in Brazil – A study of a low standard dwelling in three different Brazilian climate zones

2020 ◽  
pp. 1420326X2096115
Author(s):  
Jaime Resende ◽  
Marta Monzón-Chavarrías ◽  
Helena Corvacho
Keyword(s):  
Energy Consumption ◽  
Energy Balance ◽  
Thermal Comfort ◽  
Residential Buildings ◽  
Performance Standard ◽  
Single Family ◽  
Zero Energy ◽  
Climate Zones ◽  
Net Zero Energy ◽  
Net Zero

Buildings account for 34% of world energy consumption and about half of electricity consumption. The nearly/Net Zero Energy Building (nZEB/NZEB) concepts are regarded as solutions for minimizing this problem. The countries of Southern Europe, which included the nZEB concept recently in their regulatory requirements, have both heating and cooling needs, which adds complexity to the problem. Brazil may benefit from their experience since most of the Brazilian climate zones present significant similarities to the Southern European climate. Brazil recently presented a household energy consumption increase, and a growing trend in the use of air conditioning is predicted for the coming decades. Simulations with various wall and roof solutions following the Brazilian Performance Standard were carried out in a low standard single-family house in three different climate zones in order to evaluate thermal comfort conditions and energy needs. Results show that in milder climate zones, achieving thermal comfort with a low energy consumption is possible, and there is a great potential to achieve a net zero-energy balance. In the extreme hot climate zone, a high cooling energy consumption is needed to provide thermal comfort, and the implementation of a nearly zero-energy balance may be more feasible.

scholarly journals Thermal performance characterisation of a reverse-flow energy recovery ventilator for a residential building application

2019 ◽  
Vol 111 ◽  
pp. 01010
Author(s):  
David Hunt ◽  
Naoise Mac Suibhne ◽  
Laurentiu Dimache ◽  
David McHugh ◽  
John Lohan
Keyword(s):  
Control System ◽  
Energy Consumption ◽  
Thermal Performance ◽  
Thermal Energy ◽  
Carbon Emissions ◽  
Energy Recovery ◽  
Reverse Flow ◽  
Recovery Efficiency ◽  
Indoor Climate ◽  
Climate Control

The European Union’s 2020 and 2030 sustainable energy policies seek significant reductions in both energy consumption and carbon emissions. These policies demand a greater use of energy efficient technologies and a transition away from fossil fuels. This paper studies one such technology, an indoor climate control system with a reverse-flow enthalpy recovery ventilator, capable of recovering both sensible and latent heat. The thermal performance characteristics are established using an experimental facility and calculation methods defined by European Standard EN 13141-7:2010. This involves measurement of temperature, humidity, pressure and volumetric air flow rates over a range of operating conditions. Total thermal energy recovery rates ranged from 0.63 kW to 2.2 kW, with energy recovery efficiency of 72.8 % to 88.6 %. The recovery efficiency ratio, which reflects the capacity of the indoor climate control system to recover thermal energy relative to its power consumption ranged between 6.87 to 19.97. Due to the unique reverse-flow defrost function, the system demonstrates operation down to -7 °C without frost formation. These results highlight the potential that this system can make towards the EU goals of reducing energy consumption, operating costs and carbon emissions associated with indoor climate control.

scholarly journals Investigation of Ventilation Energy Recovery with Polymer Membrane Material-Based Counter-Flow Energy Exchanger for Nearly Zero-Energy Buildings

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1727 ◽  
Author(s):  
Miklos Kassai ◽  
Laith Al-Hyari
Keyword(s):  
Energy Consumption ◽  
Energy Recovery ◽  
Polymer Membrane ◽  
Cold Climate ◽  
Sensible Heat ◽  
Membrane Material ◽  
Zero Energy ◽  
Counter Flow ◽  
Flow Energy ◽  
Zero Energy Buildings

The usage of energy recovery ventilation units was extended in European countries. Air-to-air heat and energy recovery is an effective procedure to reduce energy consumption of the ventilation air. However, the material of the core significantly influences the performance of the exchangers, which is becoming an extremely important aspect to meet the energy requirements of nearly zero-energy buildings. In this study, the performance of two counter-flow heat/enthalpy energy exchangers are experimentally tested under different operating conditions, and the values of the sensible, latent, and total effectiveness are presented. Moreover, the effects of the material of two exchangers (polystyrene for the sensible heat exchanger and polymer membrane for the energy exchanger) on the energy consumption of ventilation in European cities with three different climates (in Reykjavík in Iceland as a cold climate, in Budapest in Hungary as a temperate climate, and in Rome in Italy as a warm climate) are evaluated. The results show that the energy recovery of ventilation air with a polymer membrane material-based counter-flow energy exchanger performs better than using a polystyrene sensible heat recovery unit.

scholarly journals Estimated potential for energy savings in heating residential buildings in Poland

2018 ◽  
Vol 49 ◽  
pp. 00068 ◽  
Author(s):  
Piotr Lis
Keyword(s):  
Energy Consumption ◽  
Energy Savings ◽  
Residential Buildings ◽  
Dominant Role ◽  
Ventilation System ◽  
Energy Effect ◽  
Central Statistical ◽  
The Face ◽  
Central Statistical Office ◽  
Reduce Energy Consumption

In the face of a constant increase in demand for energy, one of the important sources will be its saving and efficient use. The search for the greatest opportunities in this area should focus on the areas where the highest energy consumption occurs. The dominant role here is played by the communal and living sector, to the extent that it is the sub-sector of buildings with a majority share of residential buildings. The article presents the expected energy effects of measures reducing energy consumption for heating residential buildings in the whole country. The author used statistical data of the Central Statistical Office available in the database of this institution. These data were identified and searched for as suitable for the purposes of this article and were used as a basis for calculations and analyses. The calculations show that only thanks to simple actions such as improvement of thermal insulation of envelope components it is possible to reduce energy consumption for heating of residential buildings by over 70% in relation to the situation in 2011. The potential energy effect will also translate into an economic and environmental effect. Qualitative measures such as improving the performance of the heating and ventilation system of a building and/or changing the energy carrier will also reduce energy consumption for this purpose, but they are not the subject of this study.

Optimization of Regenerative Braking Control Strategy for Pure Electric Vehicle

2017 ◽  
Vol 872 ◽  
pp. 331-336 ◽  
Author(s):  
Zhi Jun Guo ◽  
Dong Dong Yue ◽  
Jing Bo Wu
Keyword(s):  
Electric Vehicle ◽  
Control Strategy ◽  
Energy Recovery ◽  
Pso Algorithm ◽  
Regenerative Braking ◽  
Recovery Efficiency ◽  
Constraint Optimization ◽  
Vehicle Model ◽  
Braking Torque ◽  
Braking Control

The regenerative braking strategy for precursor pure electric vehicle was studied in this paper. Firstly, a constraint optimization model was established for the braking force distribution, in which both braking stability and recovery efficiency of braking energy were taken into account. Secondly, Particle Swarm Optimization (PSO) algorithm was applied to optimize the multi key parameters in the model. Finally, the optimized braking torque of the motor was obtained at different speed, different braking strength and different battery charge state. A vehicle model was built to validate the optimized results through simulation. The results showed that, compared with the original control strategy, the optimized control strategy not only could increase the braking stability effectively, but also improve the energy recovery efficiency in a certain extent.

scholarly journals Energetic investigation of energy recovery technologies in air handling units

2018 ◽  
Vol 9 (1) ◽  
pp. 49-57
Author(s):  
L. F. Al-Hyari ◽  
M. Kassai
Keyword(s):  
Energy Consumption ◽  
Indoor Air ◽  
Energy Recovery ◽  
Ventilation System ◽  
Ambient Air ◽  
Existing Buildings ◽  
Exact Methods ◽  
Technical Data ◽  
Air Temperatures ◽  
Air Handling Units

The statistical data show that the application of active cooling is spread widely in residential and commercial buildings. In these buildings, the ventilation is significantly increased in the whole energy consumption. There are similar problems in the operation of post-insulation of existing buildings. In this case, the energy consumption of the ventilation system gives a major proportion of the whole building services energy consumption. The opportuneness of this research shows that the actual available calculation procedures and technical designing data are only rough approximations for analyzing the energy consumption of air handling units and the energy saved by the integrated heat or energy recovery units. There are not exact methods and unequivocal technical data. In previous researches, the production and development companies have not investigated the effectiveness of the energy recovery units under difference ambient air conditions and the period of defrost cycle when the heat recovery can only partly operate under difference ambient air temperatures. During this term, a re-heater has to fully heat up the ambient cold air to the temperature of supplied air and generate the required heating demand to provide the necessary indoor air temperature.

scholarly journals An analysis of the innovative exhaust air energy recovery heat exchanger

2018 ◽  
Vol 240 ◽  
pp. 02003 ◽  
Author(s):  
Marek Borowski ◽  
Marek Jaszczur ◽  
Daniel Satoła ◽  
Sławosz Kleszcz ◽  
Michał Karch
Keyword(s):  
Heat Exchanger ◽  
Energy Recovery ◽  
Energy Use ◽  
Dynamic Change ◽  
Ventilation System ◽  
Primary Source ◽  
Winter Period ◽  
Recovery Efficiency ◽  
Total Energy Consumption ◽  
Result Show

Heating, ventilation and air conditioning systems are responsible for a nearly 50% of total energy consumption in operated buildings. One of the most important parts of the ventilation system is an air handling unit with a heat exchanger for energy recovery which is responsible for effective and efficient energy recovery from exhaust air. Typically heat exchangers are characterised by the producers by heat and humidity recovery efficiency up to 90% and 75% respectively. But these very high values are usually evaluated under laboratory conditions without taking into account a dynamic change of outdoor and indoor air conditions significantly affecting the recovery efficiency. In this paper, results of thermal, humidity and enthalpy recover efficiency of innovative energy recovery exchanger have been presented. The analysed system allows adjustment of the humidity recovery especially useful in the winter period and forefends energy use for an anti-froze system of energy exchanger. Presented result show that analysed innovative system can achieve the value of thermal efficiency recovery higher than 90% and efficiency of humidity recovery about 80%. This is possible because the analysed system is able to work without the use of any primary source energy or other anti-freeze systems. Presented in this research unique solution is able to work without external anti-freeze systems even in extremely adverse outdoor air conditions such as minus 20°C and humidity 100% RH.

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