scholarly journals Efficacy of Energy Efficiency and Thermal Comfort Related Retrofit for Existing New Zealand Houses

2021 ◽  
Author(s):  
◽  
Yanguang Zhang

<p>Many New Zealand studies have argued that house energy retrofit produces limited benefits, but the issue of how existing house retrofitting can lead to better energy performance and comfort improvement is little explored. The aim of this thesis was to examine the influence of house retrofit on energy efficiency and thermal comfort, using house model simulation and calculation. This study gives a holistic house retrofit approach in thermal comfort improvement and energy conservation. Three house retrofit categories were defined by household energy breakdown: Space Heating Retrofit, Hot Water System Retrofit and Appliances Retrofit. This study started with an investigation of New Zealand existing house stock. A typical house model was defined by the summarized common physical characteristics. This house model was used for retrofit testing. For the building space heating retrofit study, a series of thermal simulations was completed with different retrofit options. Thermal simulation results were compared both in thermal comfort and space heating energy requirement. It was discovered that the optimum level full insulation retrofit significantly reduced space heating energy requirement and also improved thermal comfort. Retrofit solutions for water heating, lighting and appliances were compared by cost and energy saving. Cost effectiveness cross comparison for all of the retrofit solutions was carried out. Retrofitting for space heating system and hot water system can be considered for long term cost effectiveness. Appliances and lighting retrofit have a higher efficacy than other retrofit options in terms of energy saving and cost benefit cycle. These findings are used to provide suggestions for retrofitting of existing houses.</p>

2021 ◽  
Author(s):  
◽  
Yanguang Zhang

<p>Many New Zealand studies have argued that house energy retrofit produces limited benefits, but the issue of how existing house retrofitting can lead to better energy performance and comfort improvement is little explored. The aim of this thesis was to examine the influence of house retrofit on energy efficiency and thermal comfort, using house model simulation and calculation. This study gives a holistic house retrofit approach in thermal comfort improvement and energy conservation. Three house retrofit categories were defined by household energy breakdown: Space Heating Retrofit, Hot Water System Retrofit and Appliances Retrofit. This study started with an investigation of New Zealand existing house stock. A typical house model was defined by the summarized common physical characteristics. This house model was used for retrofit testing. For the building space heating retrofit study, a series of thermal simulations was completed with different retrofit options. Thermal simulation results were compared both in thermal comfort and space heating energy requirement. It was discovered that the optimum level full insulation retrofit significantly reduced space heating energy requirement and also improved thermal comfort. Retrofit solutions for water heating, lighting and appliances were compared by cost and energy saving. Cost effectiveness cross comparison for all of the retrofit solutions was carried out. Retrofitting for space heating system and hot water system can be considered for long term cost effectiveness. Appliances and lighting retrofit have a higher efficacy than other retrofit options in terms of energy saving and cost benefit cycle. These findings are used to provide suggestions for retrofitting of existing houses.</p>


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.


2009 ◽  
Vol 13 (1) ◽  
pp. 185-193 ◽  
Author(s):  
Dusan Gordic ◽  
Milun Babic ◽  
Dubravka Jelic ◽  
Davor Koncalovic ◽  
Nebojsa Jovicic ◽  
...  

This paper deals with energy audit procedure implemented on only Serbian car manufacturer 'Zastava Automobili'. Based on the results of energy auditing and performed technological and economical feasibility studies several energy saving measures were proposed. The measures are related to different energy sources: steam, hot water, compressed air, electricity, and water. Such energy efficiency programs reduce energy costs and increase production profitability of the factory.


2020 ◽  
Vol 197 ◽  
pp. 02010
Author(s):  
Giada Romano ◽  
Elisa Pennacchia ◽  
Sofia Agostinelli

Buildings with architectural constraints and recognized historical values require a careful design process, aiming to combine the needs of conservation and the adaptation of the buildings to the modern use and its accessibility. The feasible interventions consist in improving the energy performance of the building envelope, in inserting efficient technological systems and using renewable energy sources where possible. The compatibility between the architectural constraints of the building and its more sustainable future use represents a crucial challenge. This work presents the interventions designed and realized on a small villa located in the Prati district, in Rome. Starting from the requests of the client, the primary objective was to create a comfortable house both in the winter and in the summer season, with widespread use of automation systems for managing the utilities. In line with the current energy scenario, the interventions were oriented to energy efficiency, the reduction of polluting emissions, the electrification of utilities and the use of renewable energy sources. The proposed solutions showed high gains in terms of energy saving even if the changes to the building envelope were limited by the desire to preserve the values of the cultural heritage. Therefore, a virtuous refurbishment can effectively respond to current energy efficiency goals.


2018 ◽  
Vol 175 ◽  
pp. 04029
Author(s):  
Yuyang Miao ◽  
Chenggang Liu ◽  
Xinjiang Huang

Energy consumption of HVAC system play a big role on the whole building energy usage. Recommissioning on HVAC system can improve build comfort and its performance. Taking the recommissioning of public office as an example, the issue of the energy consumption of HVAC system was found, control scheme of chilled and hot water system and AHUs was optimized, the new energy saving control scheme was determined, and the actual energy consumption was analysed. The result show that recommissioning for the public office building achieved obviously effect, and the rate of energy saving is 18%, 33% and 10% for chilled water, hot water and electricity, respectively.


2019 ◽  
Vol 9 (12) ◽  
pp. 2484 ◽  
Author(s):  
Paulien Strandberg-de Bruijn ◽  
Anna Donarelli ◽  
Kristin Balksten

With an increased focus on reducing greenhouse gas emissions, energy saving is of great importance in all sectors of society. EU directives set targets for member states to reduce energy use in buildings. Energy saving in historic buildings requires special measures, balancing energy-saving renovations against the preservation of heritage values. Traditional constructions are open to vapor diffusion and generally work differently from modern constructions. Modern materials in traditional constructions sometimes damages the original material as they are usually diffusion-tight. The aim of this study was to investigate whether hemp-lime could be used as an insulation material to improve the energy efficiency of historic timber building envelopes with a rendered façade in Sweden. The objective was to determine the actual energy savings for space heating. An additional objective was to determine the actual thermal transmittance and to study thermal buffering through in-situ measurements in a full-scale wall renovated with hemp-lime. Two full-scale wall sections were constructed at the Energy and Building Design laboratory at Lund University: A traditional post-and-plank wall with a lime render (80 mm), and a post-and-plank wall with a hemp-lime render (90 mm). Energy use for space heating was monitored continuously over a period of one year. The wall with a hemp-lime render required 33% less energy for space heating than the traditional post-and-plank wall with a lime render. This was accomplished without changing the framework, appearance or material in the render and without drastically changing the hygric properties of the façade. From the gathered data, the thermal transmittance (U-values) for both walls was calculated using two different methods, one based on material properties and the other based on energy use data. For both walls, thermal transmittance based on actual energy use data during the heating period was lower than what was expected from their material properties. This indicates that more material properties than thermal conductivity and material thickness need to be taken into account when performing energy use calculations. With hemp-lime, a renovation can be accomplished without damaging the timber structure and wooden slats, and it can be done with local traditional materials and building methods with no difference in appearance to a traditional lime render. This allows for heritage values to be preserved, while also allowing the building to comply with modern standards and with increased thermal comfort and reduced energy use.


2019 ◽  
Vol 40 (4) ◽  
pp. 470-491 ◽  
Author(s):  
Radwa Salem ◽  
Ali Bahadori-Jahromi ◽  
Anastasia Mylona

The death toll of the 2003 heat wave in Europe exceeded 35,000 heat-related deaths. The elderly population were the most affected. The current paradigm within the construction industry in cold-dominant countries is to design/retrofit buildings with high levels of insulation. Whilst thermal comfort may be reached during colder months with this approach, the risk of overheating can be increased during hotter months. This paper aims to examine the impacts of a changing climate on the risk of overheating and energy performance for a UK retirement village. For this study, the buildings within the retirement village will be designed to reach the nearly zero energy building standard. Consequently, the risk of overheating of the buildings within the retirement village as they currently stand and as zero energy buildings will be investigated under current and future climatic conditions. The analysis is carried out using thermal analysis simulation software (TAS, Edsl). Combined heat and power and combined cooling, heat and power will be investigated as mitigating strategies with regard to overheating. The results of this study do not undermine the importance of continuing to improve the energy efficiency of existing buildings but rather highlight that the approach undertaken should be reconsidered. Practical application: Currently, there is emphasis placed on retrofitting and designing buildings, with high energy efficiency standards. Whilst this is in line with our vision as a society towards reaching a decarbonised, sustainable future, this work highlights that doing so, carries risks with regard to overheating. Nonetheless, the results demonstrate that with the incorporation of suitable mitigation strategies and adequate ventilation strategies, it is possible to achieve an energy efficient building that meets the heating and cooling demand (and thereby thermal comfort of occupants) during the heating and non-heating season.


2011 ◽  
Vol 347-353 ◽  
pp. 587-590
Author(s):  
Qing Hai Luo ◽  
Zheng Zuo

This paper analyzes the energy consumption of hot water supply in buildings and the insurmountable shortcoming of low energy efficiency of conventional water heaters, and investigates the progress and problems of developing heat pump water heaters. It is pointed out that developing of heat pump water heaters is one of the efficient approaches to improve the energy efficiency of hot water supply.


2014 ◽  
Vol 1020 ◽  
pp. 518-523
Author(s):  
Martin Kovac ◽  
Katarina Knizova

The subject of the paper is to calculate the energy performance of building in proposed variants. The differences in the variants are in the using of conventional and renewable sources for heating and domestic hot water system. Target of the second part of paper is to know, how much money we need to invest into the proposed variants for heating and domestic hot water systems and how much money will by the user paying for operating costs. The conclusion of the paper describes the payback periods of proposed variants.


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