scholarly journals Controlled Mechanical Ventilation in Buildings: A Comparison between Energy Use and Primary Energy among Twenty Different Devices

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2123 ◽  
Author(s):  
Lamberto Tronchin ◽  
Kristian Fabbri ◽  
Chiara Bertolli

Indoor air quality (IAQ) of buildings is a problem that affects both comfort for occupants and the energy consumption of the structure. Controlled mechanical ventilation systems (CMVs) make it possible to control the air exchange rate. When using CMV systems, it is interesting to investigate the relationship between the useful thermal energy requirements for ventilation and the energy consumption of these systems. This paper addresses whether there is a correlation between these two parameters. The methodology used in this work involves the application of equations of technical Italian regulations UNI/TS 11300 applied to a case study. The case study is represented by a 54 m3 room, which is assumed to have three CMV systems installed (extraction, insertion, insertion and extraction) for twenty different devices available on the market. Afterwards, simulations of useful thermal energy requirements QH,ve and primary energy EP,V were performed according to the electrical power of each fan W and the ventilation flow. The results show that the two values are not linearly correlated: it is not possible to clearly associate the operating cost for CMV systems according to building requirements. The study also shows that CMV systems are particularly efficient for high-performance buildings, where there is no leakage that can be ascribed to windows infiltrations.

Buildings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 190
Author(s):  
Irina Susorova ◽  
Brent Stephens ◽  
Benjamin Skelton

A common envelope performance problem in buildings is thermal bridging through balcony slab connections, which can be improved with the use of commercially available thermal break products. Several prior studies have used simulation-based and/or hot box test apparatus approaches to quantify the likely effect of balcony thermal breaks on effective thermal resistance of building enclosures. However, in-situ measurements of thermal performance in real buildings remain limited to date. This study uses a combination of field measurements and models to investigate the effects of installing balcony thermal breaks on the interior surface temperatures, effective thermal resistance, and annual building energy consumption. For the field experiment, yearlong measurements were conducted on the 13th floor of a 14-story multi-family building in Chicago, IL, in which thermocouple sensors were embedded into eight balconies and their adjacent interior floor slabs just before concrete was poured to complete the construction. The eight balconies included four control balconies without thermal breaks and four thermally-broken balconies with a commercially available thermal break product installed. The experimental data were then combined with 2-D heat transfer modeling and whole building energy simulations to investigate the impacts of the thermal break product installation on the envelope thermal resistance and overall energy use in the case study building as well as in several more generic building designs with simpler geometries. The results demonstrate that although the balcony thermal breaks helped regulate interior slab temperatures and improved the effective thermal resistance of the curtain wall enclosure assembly by an estimated ~14% in the case study building, the predicted effect on annual energy consumption in all modeled building types was small (i.e., less than 2%). The results also highlight the importance of paying careful attention to envelope design details when using thermal break products and considering the use of thermal break products in combination with other energy efficiency strategies to achieve high performance enclosures.


2018 ◽  
Vol 13 (1) ◽  
pp. 59-69
Author(s):  
Anton Pitonak ◽  
Martin Lopusniak ◽  
Miloslav Bagona

Abstract In countries of the European Union, the proportion of buildings in the overall energy consumption represents 40% and their proportion in CO2 emissions 35%. Taking into account dependence of the European Union on import of energy, this represents large quantity of energy and CO2 emissions, in spite of the fact that there exist effective solutions for reduction of building energy demand. In Directive 20-20-20, the European Union adopted three main commitments of fulfillment criteria by 2020. On the basis of this directive, the Slovak Republic declares support of renovation of apartment dwelling houses. Taking into account the fact that state subsidy can be obtained only once, and energy requirements of the European Union are increasingly stricter, a comprehensive approach to renovation of buildings is inevitable. At the same time, it is inevitable to propose the renovation of buildings taking into account requirements stated for buildings for year 2020. Two areas were compared within the case study taking into account primary energy and the quantity of CO2 emissions. Both areas have the same built-up area, but one of them is a district city and the second is a suburb. From results it is obvious that the quantity of primary energy is lower by 88% in the district city than in the suburb. The quantity of CO2 emissions is lower by 69% in the district city than in the suburb.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Arif Budiyanto ◽  
Muhammad Hanzalah Huzaifi ◽  
Simon Juanda Sirait ◽  
Putu Hangga Nan Prayoga

AbstractSustainable development of container terminals is based on energy efficiency and reduction in CO2 emissions. This study estimated the energy consumption and CO2 emissions in container terminals according to their layouts. Energy consumption was calculated based on utility data as well as fuel and electricity consumptions for each container-handling equipment in the container terminal. CO2 emissions were estimated using movement modality based on the number of movements of and distance travelled by each container-handling equipment. A case study involving two types of container terminal layouts i.e. parallel and perpendicular layouts, was conducted. The contributions of each container-handling equipment to the energy consumption and CO2 emissions were estimated and evaluated using statistical analysis. The results of the case study indicated that on the CO2 emissions in parallel and perpendicular layouts were relatively similar (within the range of 16–19 kg/TEUs). These results indicate that both parallel and perpendicular layouts are suitable for future ports based on sustainable development. The results can also be used for future planning of operating patterns and layout selection in container terminals.


2021 ◽  
Vol 13 (11) ◽  
pp. 6192
Author(s):  
Junghwan Lee ◽  
Jinsoo Kim

This study analyzes the changes in energy consumption of the Korean manufacturing sector using the index decomposition analysis (IDA) method. To capture the production effect based on actual physical activities, we applied the activity revaluation (AR) approach in the analysis. We also developed energy consumption data in terms of primary energy supply to consider conversion loss in the energy sector to avoid any distortions in the intensity effect. The analysis covers every manufacturing subsector in Korea over the period between 2006 and 2018. Combining two distinctive approaches from the previous literature, the AR approach and primary energy-based analysis gives us helpful findings for a climate policy. First, the overall activity effect estimated from the physical output indicator is lower than that from the monetary output indicator. The monetary indicator shows that the share of energy-intensive industries decreases, whereas the physical indicator shows the opposite. Second, in terms of energy efficiency, the intensity effect is estimated as an increasing factor of energy use, whereas inversed results are shown when we use the monetary indicator. Lastly, unlike the previous studies, the AR approach results indicate that Korean manufacturing sectors have been shifting toward an energy-intensive, so it is hard to anticipate positive intensity effects, which means decreasing energy consumption factor, for a while. These results support why analyzing the driving forces of energy consumption through the AR approach and primary energy base is highly recommended.


Environments ◽  
2018 ◽  
Vol 5 (11) ◽  
pp. 119 ◽  
Author(s):  
Alessia Arteconi ◽  
Luca Del Zotto ◽  
Roberto Tascioni ◽  
Khamid Mahkamov ◽  
Chris Underwood ◽  
...  

In this paper, the smart management of buildings energy use by means of an innovative renewable micro-cogeneration system is investigated. The system consists of a concentrated linear Fresnel reflectors solar field coupled with a phase change material thermal energy storage tank and a 2 kWe/18 kWth organic Rankine cycle (ORC) system. The microsolar ORC was designed to supply both electricity and thermal energy demand to residential dwellings to reduce their primary energy use. In this analysis, the achievable energy and operational cost savings through the proposed plant with respect to traditional technologies (i.e., condensing boilers and electricity grid) were assessed by means of simulations. The influence of the climate and latitude of the installation was taken into account to assess the performance and the potential of such system across Europe and specifically in Spain, Italy, France, Germany, U.K., and Sweden. Results show that the proposed plant can satisfy about 80% of the overall energy demand of a 100 m2 dwelling in southern Europe, while the energy demand coverage drops to 34% in the worst scenario in northern Europe. The corresponding operational cost savings amount to 87% for a dwelling in the south and at 33% for one in the north.


Author(s):  
Jerzy Sowa ◽  
Maciej Mijakowski

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.


2020 ◽  
Vol 12 (16) ◽  
pp. 6563
Author(s):  
Roque G Stagnitta ◽  
Matteo V Rocco ◽  
Emanuela Colombo

Energy balances have been historically conceived based on a supply-side perspective, providing neither detailed information about energy conversion into useful services nor the effects that may be induced by the application of policies in other sectors to energy consumption. This article proposes an approach to a thorough assessment of the impact of efficiency policies on final energy uses, focusing on residential space heating and cooling, and capable of: (1) quantifying final useful services provided and (2) accounting for the global impact of efficiency policies on final energy use, taking advantage of Input–Output analysis. This approach is applied in five cities of Argentina. Firstly, the quantity of energy service provided (i.e., level of thermal comfort) for each city is evaluated and compared with the defined target. It is found out that heating comfort is guaranteed approximately as established, whereas in the cooling case the provision is twice the established level. Secondly, primary energy consumption of heating and cooling services is evaluated before and after different efficiency improvement policies. The results show that the major primary energy saving (52%) is obtained from the upgrading appliances scenario and reflect the importance of accounting for embodied energy in goods and services involved in interventions.


Author(s):  
Ali A. Jal-Alzadeh-Azar ◽  
Ren Anderson ◽  
Keith Gawlik

This paper demonstrates the potential impact of indoor air distribution on the energy consumption of central HVAC systems with cognizance of human thermal comfort. The study focuses on a hypothetical high-performance house incorporating a split heat pump system. The air distribution of this building incorporates high sidewall supply-air registers and near-floor, wall-mounted return-air grilles. Heating-mode stratification resulting from this prevalent configuration is a prime example of situations in which challenges regarding energy efficiency, comfort, and ventilation effectiveness emerge. These challenges underline the importance of adopting a comprehensive design strategy for high-performance buildings. Two indoor air distribution scenarios were analyzed: (1) theoretically well mixed and (2) poorly mixed, representing a realistic case. The former scenario was evaluated using an analytical approach, whereas the latter was investigated through computational fluid dynamics (CFD) simulations. For heating mode, the results indicated the presence of a pronounced thermal stratification resulting from poor air mixing. At 50% of the design heating load, for the well-mixed case, the HVAC system energy consumption was significantly higher. Considerably better air distribution performance was observed with cooling mode, in which the relative energy penalty for the well-mixed scenario was noticeably less. In real-world applications where measures must be taken to achieve near perfectly mixed indoor conditions for better comfort, the energy use is expected to be even higher. However, in the absence of such measures, the thermostat setpoint is likely to be readjusted, leading to a higher energy use without necessarily improving the overall comfort level, as demonstrated in this paper. The limitation of increasing the supply-air flow rate to enhance air mixing and diffusion is also discussed in terms of the system moisture removal capability.


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