Next Article in Journal
Compact and Integrated High-Power Pulse Generation and Forming System
Next Article in Special Issue
Study on Air-to-Water Heat Pumps Seasonal Performances for Heating in Greece
Previous Article in Journal
Does Deterioration of Aerodromes’ Economic Situation Influence the Level of Safety in Civil Aviation? What Can Be Done to Prevent It in Line with a Sustainable Transport Systems Approach?
Previous Article in Special Issue
Influence of Cold Water Inlets and Obstacles on the Energy Efficiency of the Hot Water Production Process in a Hot Water Storage Tank
Article

Review on Ventilation Systems for Building Applications in Terms of Energy Efficiency and Environmental Impact Assessment

Process Equipment Design Laboratory, Department of Mechanical Engineering, School of Engineering, Aristotle University, 54124 Thessaloniki, Greece
Academic Editor: Christian Veje
Energies 2022, 15(1), 98; https://doi.org/10.3390/en15010098
Received: 31 October 2021 / Revised: 15 December 2021 / Accepted: 16 December 2021 / Published: 23 December 2021
(This article belongs to the Special Issue Energy and Environmental Management of Buildings and Systems)

Abstract

Buildings are responsible for approximately 30–40% of energy consumption in Europe, and this is a fact. Along with this fact is also evident the existence of a defined and strict legislation framework regarding energy efficiency, decarbonization, sustainability, and renewable energy systems in building applications. Moreover, information and communication technologies, along with smart metering for efficient monitoring, has come to cooperate with a building’s systems (smart buildings) to aim for more advanced and efficient energy management. Furthermore, the well-being in buildings still remains a crucial issue, especially nowadays that health and air quality are top priority goals for occupants. Taking all the above into consideration, this paper aims to analyze ventilation technologies in relation to energy consumption and environmental impact assessment using the life cycle approach. Based on the review analysis of the existing ventilation technologies, the emphasis is given to parameters related to the efficient technical design of ventilation systems and their adequate maintenance under the defined guidelines and standards of mechanical ventilation operation. These criteria can be the answer to the complicated issue of energy efficiency along with indoor air quality targets. The ventilation systems are presented in cooperation with heating and cooling system operations and renewable energy system applications ensuring an energy upgrade and reduced greenhouse gas emissions. Finally, the mechanical ventilation is examined in a non-residential building in Greece. The system is compared with the conventional construction typology of the building and in cooperation with PVs installation in terms of the environmental impact assessment and energy efficiency. The methodology implemented for the environmental evaluation is the Life Cycle Analysis supported by OpenLca software.
Keywords: ventilation systems; energy efficiency; life cycle analysis; environmental impact assessment ventilation systems; energy efficiency; life cycle analysis; environmental impact assessment

1. Introduction

The defined objectives for clean energy, reduced greenhouse gas emissions, and sustainable and resilient infrastructure in terms of circularity and social sensitivity set the base for future accomplishments in the building sector. The targets for reducing carbon emissions have been rescheduled based on the European Green Deal. The target of 20-20-20 has almost been attained in the majority of EU countries.
Within this framework, on 14 July, the EU has reformed and updated the future goals for energy and environment in order to reduce CO2 emissions by at least 55% by 2030, compared to 1990 levels. Achieving these ambitious emission reductions in the next decade sets the base for a carbon neutral EU by 2050, and makes the European Green Deal a realistic target for EU members.
Focusing on Renewable Energy Sources (RESs), the European Union aims to achieve a 20% share (of its final energy consumption) from RES by 2020, and at least a 32% share (not broken down into nationally binding targets) by 2030. The key instruments at the EU level to promote RESs include directives, such as the 2009 Renewable Energy Directive [1]. The EU supports the legislative framework with schemes and financial programmes. For instance, the EU Emission Trading Scheme (ETS) is one of the EU’s efforts to support RES implementation. On one hand, there is the demand of EU regulations, and on the other hand, there is the need for developing health buildings ensuring users quality of living. Indoor air quality is an important consideration for health and well-being, since people worldwide spend most of their time indoors, either at home or at their workplace. Undoubtedly, monitoring and improving the indoor air quality in homes, workplaces, and public facilities can lead to an increased understanding of indoor air pollution and its effects on health, and the formation of a global regulatory framework for indoor air quality, which is currently lacking. Indoor air pollution is a complicated mixture of particulate and various gaseous components, and the compositions differ significantly depending on sources, emission rates, and ventilation conditions.
The main indoor air pollutants are PM, VOCs, CO, CO2, ozone, radon, heavy metals, aerosols, pesticides, biological allergens, and microorganisms. In general, indoor air pollution originates either from outdoor-to-indoor infiltration or through various occupants’ activities (e.g., heating, cooling, cooking) and emissions from construction materials and indoor equipment [2]. In this direction, implementing smart air disinfection and purification devices (e.g., HVAC, robots) and materials to improve air quality, powered by automatic decision support and personalized guidance, is a key issue in building management in terms of air quality, energy efficiency, and environmental impact.
The design, control, and identification of the technical characteristics of the central heating and air conditioning systems for buildings is feasible in terms of energy efficiency, thermal comfort, and indoor air quality. Operational conditions, indoor environmental parameters (air flow, air infiltration, thermal comfort) as well as occupants’ behavioral characteristics can be used in order to ensure the minimization of pollutants in indoor environments.
The main objective of this paper is to underline the significance of ventilation and present the different types and technologies. The effects of ventilation technology implementation are related to:
health and well-being, which are, especially nowadays, key issues for building management and the protection of users;
cooperation with other energy systems in the building ensuring thermal comfort and energy efficiency;
environmental impact analysis, which proved to be the scientific gap as there were no significant applications based on the literature review on this scientific area.
More specifically, the paper presents, based on the literature review, the basic benefits of ventilation technologies, mainly focused on energy efficiency, as well as the health and well-being of users, and it identifies the gap in the environmental impact analysis. The attempt to close this gap and give an answer to the environmental impact of ventilation technologies was given with the LCA implementation in an office building in Greece.

2. State-of-the-Art Overview of Ventilation System Technologies

The main target of ventilation systems is to supply the indoor environment with fresh air, aiming to improve the air quality and ensuring the energy efficiency improvement in cooperation with the heating and cooling systems. The air exchange rate depends on several parameters, such as the type of activities, the number of users, the hours of occupancy in the building, the type of building, the behavioral characteristics of occupants, or the climatic conditions [3]. Therefore, it is important to understand that ventilation is a technical issue with societal parameters that should definitely count towards the system’s operational conditions. The basic ventilation systems are mainly categorized into three types:
natural ventilation (NV);
mechanical ventilation (MV);
and hybrid ventilation systems (HVs).
Natural ventilation is the air input with natural forces and depends significantly upon the architecture of the building. NV does not use mechanical components to achieve ventilation. It is evident that in order to improve and, in a way, boost the NV, it is possible to add mechanical parts to the ventilation system, such as exhaust air units. In this way, the HV is created, which is actually the combination of NV with mechanical assistance in order to ensure the air exchange and indoor air quality. Most of the time, the HVs combine smart sensoring applications to control the air exchange and take advantage of the weather conditions to permit the fresh air flow in the building.
The accurate design of automations are of major importance in reducing energy use and attaining the appropriate indoor air quality levels in indoor environments. These systems are often designed with the help of computational fluid dynamics (CFD) simulations. Keeping in mind that it is an EU as well as national legislative demand to improve energy efficiency in buildings, the ventilation systems should also contribute to this direction. Concerning the MV systems, the heat recovery ventilation (HRV) systems as well as the energy recovery ventilation (ERV) systems provide the indoor environments with fresh air. This kind of ventilators insert clean air in the building and expel stale air, while keeping 70% to 90% of the heat from the discharged air and returning it to the incoming air. Moreover, HRVs and ERVs assist to moisture control in the air. Both systems have the same technical operation, but there are some differences in the material used in the heat exchanger. Without a doubt, MV systems overcome the restrictions of NV systems and do not depend on weather conditions providing a constant environment in terms of air quality, but there are definitely some issues to discuss. The MV systems should be well-designed, properly installed, and maintained in order to have positive results. Otherwise, not only do these systems not arrive to the expected results, but they also cause extra health problems to the vulnerable population. For instance, an improperly maintained filter or a filter with non-certified materials can cause infectious diseases. On the other hand, NV is definitely more cost-effective compared to MV systems, but it depends on weather conditions and behavioral parameters. The main applications of ventilation technologies (Table 1) are focused on energy efficiency but mainly to the improvement of indoor air quality and the health and well being of users [3,4].
Aflaki et al. [5] focused mainly on the examination of ventilation systems in tropical climates and on natural ventilation measures and systems applied in the building facade. The majority of the case studies have given technical details about the fan power, air tightness, and heat recovery. The natural ventilation applications are mainly related to openings, air circulation, and infiltration rate. The ventilation systems are strongly connected with the energy efficiency and the energy consumed in the buildings because they also affect the heating and cooling process.
Based on the European Ventilation Industry Association (EVIA) [45], the energy consumption with mechanical ventilation systems is 20–25 kWh/m2/yr while with hybrid ventilation systems the energy consumed is lower, at about 7–8.5 kWh/m2/yr. Along with the energy benefits, the health and economic benefits from the reduction of operational costs because of the ventilation interventions is another point to be discussed based on the analysis by Yuan [46], who proved the positive impact of ventilation systems by reducing PM2.5 in indoor and outdoor origins in urban Beijing. According to Niemelä, the simulation of heat pumps could also improve the energy efficiency of buildings [47].
An issue that is essential to be discussed and analyzed is the cost effectiveness of the ventilation systems, because it is evident that a new system has an initial cost that should be balanced with the profit of the operational cost reduction and have a low payback period. In this term, the investment is definitely cost-effective. Therefore, in the design stage, apart from the technical specification and the appropriate conjunction with the other mechanical systems, the cost effectiveness should also be determined. For example, mechanical ventilation with heat recovery, which is a very common application in buildings, is a more complex system that needs more components and more materials because it includes ventilation ducts (steel use), the insulation of the ducts (in most cases rock-wool), an air supply exhaust unit (electro-galvanized steel and plastic), air exhaust fans (galvanized steel and iron), an air handling unit (galvanized steel and aluminum), and a silencer mechanism (galvanized steel and mineral wool). All these extra components need to be examined in terms of cost, but also in terms of environmental impact assessment. The production and use of these materials are responsible for environmental impacts, and this is also a point of analysis in the life cycle of buildings. In that sense, a life cycle approach of the systems is a useful tool to quantify the environmental impact. To conclude, HV systems or MV systems with a proper technical design, adequate maintenance, and the synergy with the heating and cooling systems of the building under the defined guidelines and standards of mechanical ventilation operation can be the answer to the complicated issue of energy efficiency, along with the indoor air quality targets [48,49].
Ventilation is an important parameter for energy efficiency in buildings, which is why airtightness levels are included in the legislation framework, as well as in the technical guidelines and standards. Efficient airtightness levels positively affect the design and installation of heating and cooling systems, and therefore, the energy consumption. Moreover, ventilation, as mentioned above, contributes to indoor air quality, which significantly affects the occupants’ well-being and quality of living. An important role in energy efficiency is the optimization of ventilation in a way that ensures the indoor air quality standards and does not exceed the energy consumption levels because of the continual operation of the ventilation systems. Taking this under consideration, emerging technologies such as advanced ventilation systems, smart sensoring and monitoring, internet of things, and automations provide solutions towards the optimization of the ventilation systems. In order to increase the effectiveness of pollutant removal and reduce heating and cooling energy demands in buildings, a time-controlled air supply is proposed by using CFD simulations [35]. Emerging technologies and innovative materials are also implemented in mechanical ventilation, as is the case of Phase-Change Material (PCM) in mechanical ventilation systems and the effect on thermal performance [50] as well as the dynamic simulations for the optimization of energy systems [51].

3. Results on Ventilation Systems Application in Non-Residential Buildings: The Environmental Impact Assessment Analysis

In order to evaluate the ventilation system in cooperation with the other mechanical systems of the building, the life cycle approach is used. The goal is to connect the use of ventilation systems with the energy consumption and the use stage of the building. The Life Cycle Assessment (LCA) methodology ensures the evaluation of the environmental impacts of a product’s life cycle based on ISO 14040 and 14044 standards, which provide the framework for LCA implementation.
LCA methodology aims at assessing the potential environmental impacts of a product or a service during its whole life cycle. According to ISO 14040, an LCA study shall be divided into the following main steps [52]:
  • Goal and scope definition: in this stage, the functional unit and the system boundaries are determined;
  • LCI (life cycle inventory): the initial system is separated into different subsystems and the energy as well as the materials input are quantified and registered;
  • LCIA (life cycle impact assessment): all the environmental impacts are estimated for all the processes set in the LCI; a specific characterization factor determines its impact in the studied impact category. Normalization can also be used in this stage of analysis.

4. Interpretation of the Results: Discussion of the Results, Conclusions, Sensitivity Analysis, Improvement Suggestions, Uncertainty

For the system environmental impact assessment, the Ecoinvent database and the OpenLCA (GreenDelta Company, Berlin, Germany) software are used. The basic environmental impacts evaluated are climate change, acidification, eutrophication, photochemical oxidation, and abiotic sources depletion. The system analyzed in terms of energy and environmental impact is an office building in Greece constructed in 1990. The building has a typical concrete block masonry. More specifically, and as far as the insulation, the building is insulated with stone wool. The height of the floor is 3.6 m, while, as can be seen from the picture, the length of the masonry is 2.8 m. Three scenarios are studied related to the energy efficiency and environmental impact assessment in the construction and use phase:
Scenario 1 (SC1) is the conventional one, without extra ventilation systems or renewable energy systems. Therefore, in SC1, the building has a NV system according to the architectural design and the openings in the envelope. The typical construction typology of the building envelope is based on the requirements of the Energy Performance of Buildings and forms the construction input for SC1. The external wall is formed by a typical medium-weight brick wall, insulated with extruded polystyrene (XPS) of 10 cm thickness, while also including a single-layer gypsum board with 12.5 mm thickness on the interior side and a layer of gypsum plaster on the exterior. All the internal walls consist of two double-layer gypsum boards at about 25 mm thickness. The floor and ceiling consist of a 150 mm concrete slab with no additional coating;
In Scenario 2 (SC2), a renewable energy system and more specific PVs are added. Some technical details related to PVs are defined (Table 2). Moreover, it is worth mentioning that the PV system is implemented in the building facade;
Scenario 3 (SC3) is a combination of renewable energy systems, PVs, as well as mechanical ventilation in order to reduce the heat exported from the PVs operation and therefore contribute to the building’s cooling in summer. The technical details related to the MV system are presented (Table 3). In SC1, the conventional case study, the total annual consumption is at about 150 kWh/m2.
Inevitably, the high temperatures resulting from the absorption of heat by the solar radiation reduce the efficiency of the solar cells of the PV at SC2. This will probably have an effect on the life cycle of the system, leading to the maintenance and replacement of the technical components and the significant reduction of the life cycle, and even the system’s end of life. Based on Giama and Papadopoulos, the maintenance or collapse of a system means extra raw materials, new production of products, and thus extra energy and sources in terms of circularity, and this will definitely mean greater environmental impacts [53]. Furthermore, a lack of ventilation tends to cause condensation within the building structure (much more so if ventilation is completely absent). Moreover, overheating in indoor environments can negatively affect the occupants and cause thermal discomfort.
To achieve this, one can configure a naturally ventilated open channel at the back of the photovoltaic panel. This measure not only provides effective means of releasing heat, but also helps to reduce the thermal gain of the building shell. The air in the channel behind the photovoltaic units can be circulated either with the help of electromechanical equipment (blowers, pumps, compressors), which operates from the generated current, or passively, with natural ventilation that utilizes the power of buoyancy.
The fluid flow and heat transfer to the photovoltaic facade cavities are extremely important for improving the energy efficiency and thermal behavior of the building. The relevant research has been thoroughly engaged in the theoretical and numerical modeling of air flow and heat transfer in the air duct behind the photovoltaic units. Sandberg and Moshfegh [54] investigated the flow of fluid behind photovoltaic modules implemented in the building shell using CFD analysis. In addition, photovoltaics installed on the facades of buildings increase the overall heat compared to PVs installation on the roof; in this way, the energy efficiency is reduced. [55]. Finally, taking the building as a parameter for evaluating the energy efficiency, the combination of mechanical ventilation with PVs increases energy efficiency, reduces the final energy consumed, reduces thermal load in summer, and also prevents the accumulation of snow on PV cells in winter, a parameter that reduces PVs technical efficiency. The equipment used for the mechanical ventilation of the photovoltaic cells consists of three fans, a tangential power of about 50 W and an air supply of 350 m3/h each. The profile dimensions of the fans are 10 × 10cm with a length of 60 cm and there is no air heating system (coil).
The PV system in SC2 does not fully cover the building’s demand for electricity but reduces the energy consumption at about 10–15%. For the environmental impact analysis, it was considered that 127 kWh m2 per year will be covered by the conventional energy source of the country and the rest from the PV system. In correspondence to SC2, the SC3 installs the mechanical ventilation in order to improve indoor air quality and also reduce the final energy consumption by controlling the heat produced form the PVs installation. Specifically, as for the MV system, a total of three tangential flow fans with a power of about 50 W each and an air supply of around 350 m3/h are used. The electricity saved by the use of mechanical ventilation was considered to be around 7% compared to the previous scenario, so the total requirement of the building is reduced to 118 kWh/m2. According to Nilsson’s [56] impact assessment results, validation has been implemented (Table 4) according to the environmental impact findings presented in Table 5. The environmental impact assessment results are in detail, presented per scenario and stage of life cycle analysis in Table 5. More specifically, the environmental impacts analyzed are climate change, ozone depletion, acidification, eutrophication, and photochemical oxidation.
Both systems were related with office building operations. The indicator was normalized to the surface dimension in order to be comparable. The climate change impact is higher in the case of the Greek office building because apart from the mechanical ventilation system operation, there is also PV implementation. The environmental impact assessment is calculated with CML indicators under the LCA methodology implementation. According to the LCA results and for SC3, in which the ventilation system is implemented, the most significant contribution to the environmental impacts of acidification, eutrophication, radiation, and ozone depletion is the use phase because of the energy consumption. It is worth mentioning that for climate change, the construction phase is most responsible for the environmental impact at about 90%, while the use phase contributes only 10% (Table 6).

5. Discussion—Further Research

Without a doubt, the main objective for advanced ventilation systems is the air disinfection and purification of devices in a smart and digitalized manner. The complicated issue of energy efficiency along with indoor air quality and the well-being of users is the future challenge of ventilation systems. In addition to all these, cost effectiveness is always one of the parameters that one should not forget when designing and implementing a system. Supporting smart systems and keeping in mind the Green Deal objectives for net emissions of greenhouse gases by 2050, economic growth, and saving resource use, having circular economy as a guide and the social aspect high in the agenda. In this direction, new technologies, innovative materials, and dynamic simulations support the entrance and the synergy of advanced energy systems in buildings.
Another significant parameter is the integrated design, control and identification of technical characteristics considering the central heating and air conditioning systems for buildings in terms of energy efficiency, thermal comfort, and indoor air quality with the use of specialized simulation tools in order to optimize the parameters examined. The outputs from the dynamic simulation focusing on HVAC systems operation, indoor environmental parameters (air flow, air infiltration, thermal comfort), as well as occupants’ behavioral characteristics can be used in order to ensure the minimization of pollutants in indoor environments. All methods and multiscale simulations can be used to capture spatiotemporal patterns and correlate the impact of varying indoor conditions on the efficiency and the energy consumption of HVAC systems, recommending suitable energy systems and operational scenarios based on optimum indoor environmental conditions. Another significant parameter in smart designing and the efficient control of buildings is sensoring. Cost-effective sensor technologies for monitoring air pollutants have undergone rapid progress in recent years, providing easier-to-use portable tools for gathering highly temporally resolved data in real time. Future analyses will focus on the evaluation of ventilation systems in collaboration with other energy systems and innovative technologies providing the health and well-being of occupants along with resilience in the building’s management.

6. Conclusions

The depletion of natural resources, the high, intensive energy consumption from manufacturing processes, and the increased GHG emissions from industry and other sectors have led to an increased awareness towards environmental issues. Moreover, there is a defined EU strategy towards energy-saving measures, clean energy use, RES introduction, and reduced CO2 emissions. National legislation framework and EU funding programmes are in total compliance with EU energy and environmental policy and Green Deal objectives for energy and environment. Within this framework, in this manuscript, the environmental impact related to ventilation systems based on the life cycle thinking approach has been examined.
The ventilation technologies have been presented in detail based on the review analysis. The basic ventilation technologies implemented in residential as well as non-residential buildings are natural ventilation (NV), mechanical ventilation (MV), and hybrid ventilation systems (HV). Based on the need for compliance with the defined legislation framework presented, considering energy efficiency and carbon emissions as well as environmental impact connected with well-being of users, MV is examined in a non-residential building in Greece. MV is compared with the conventional construction typology of the building and also in cooperation with PVs installation. The methodology implemented for the environmental impact assessment is the Life Cycle Analysis supported by OpenLca software (GreenDelta Company, Berlin, Germany).
Specifically, as for the MV system, a total of three tangential flow fans with a power of about 50 W each and an air supply around 350 m3/h are implemented. The electricity saved by the use of mechanical ventilation was considered about 7% compared to the previous scenario with the conventional typology and no MV addition, so the total requirement of the building is reduced to 118 kWh/m2. The environmental impact assessment results are presented in detail per scenario and stage of life cycle analysis. More specifically, the environmental impacts analyzed are climate change, ozone depletion, acidification, eutrophication, and photochemical oxidation. According to the LCA results, for SC3, in which the ventilation system is implemented, the most significant contribution to the environmental impacts of acidification, eutrophication, radiation, and ozone depletion is the use phase because of the energy consumption. It is worth mentioning that for climate change, the construction phase is most responsible for the environmental impact at about 90% while the use phase contributes only 10%.
Based on the LCA results (Table 5 and Table 6), the construction phase contributes at about 70% to the environmental impact of climate change compared to the use phase (28%) and transportation, which counts less than 1%. The significant contribution of the material use, therefore the construction phase, counts for other environmental impacts, such as the depletion of abiotic sources (almost 90% comparing to 10% of use phase and only 0.02% due to transportation). To conclude, climate change and the depletion of abiotic sources are more affected by the construction phase, while other environmental impacts, such as acidification, eutrophication, human toxicity, ozone depletion, and photochemical oxidation are affected by the use phase and energy consumption. More specifically, the use phase contributes at about 99% for acidification, 93% for eutrophication, 94% for human toxicity, 99% for ozone depletion, and 99% photochemical oxidation, while the correspondence percentage for the construction phase is less than 8%.
Ventilation is not only suggested as an intervention related only to energy efficiency, but also for the significant contribution to indoor air quality. The requirements, which are specified by the legislation framework, standards and technical regulations are basically the air speed, the maximum operating temperature in summer, the minimum operating temperature in winter, the maximum carbon indicators, the occupants, the operating hours, and in some cases, the daylight factor, as well.
In this direction, implementing smart air disinfection and purification devices (e.g., HVAC, robots) and materials to improve air quality, powered by an automatic decision support and personalized guidance is a key issue in building management in terms of air quality, energy efficiency, and environmental impact. The implementation of different types of ventilation contributes to the improvement of energy efficiency. This can be resulted from the three scenarios presented and the quantification of the energy used in the scenario where the mechanical ventilation is implemented. Nevertheless, the strongest benefit of ventilation is not the energy efficiency but the improvement of indoor quality and the well-being of occupants, and this is the key issue of the analysis presented. Finally, parameters such as the synergy of different systems, innovative materials and filtration in HVAC systems, and controlled air supply are also proposed by using CFD simulations contributing to great extent to the efficiency of the systems implemented in buildings, also positively affecting the environment in terms of climate change.

Funding

The research work was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the “First Call for H.F.R.I. Research Project to support Faculty members and Researchers and the procurement of high-cost research equipment grant” (Project Number: 4104).

Data Availability Statement

Not applicable.

Acknowledgments

The author would like to express their gratitude to the Hellenic Foundation for Research and Innovation.

Conflicts of Interest

The author declares no conflict of interests.

Nomenclature

NVNatural Ventilation
MVMechanical Ventilation
HVHybrid Ventilation
CFDComputational Fluid Dynamics
ERVEnergy Recovery Ventilation
HRVHeat Recovery Ventilation
VAVVariable Air Volume

References

  1. Giama, E.; Kyriaki, E.; Papadopoulos, A.M. Energy policy and regulatory tools for sustainable buildings. In IOP Conference Series: Earth and Environmental Science; Alsema, E., de Wild, M.J., Eds.; IOP Publishing: Bristol, UK, 2020; Volume 410, p. 012078. [Google Scholar] [CrossRef]
  2. Antoniadou, P.; Giama, E.; Papadopoulos, A.M. Analysis of environmental aspects affecting comfort in commercial buildings. SI Therm. Sci. 2019, 22, 819–830. [Google Scholar] [CrossRef]
  3. Dahlbom, K.; Ahlström, G.; Barany, M.; Kihlgren, A.; Gunnarsson, L.G. Muscular dystrophy in adults: A five-year follow-up. Scand. J. Rehabil. Med. 1999, 31, 178–184. [Google Scholar] [CrossRef] [PubMed]
  4. Chartier, Y.; Pessoa-Silva, C.L. Natural Ventilation for Infection Control in Health-Care Settings; World Health Organization: Geneva, Switzerland, 2009; ISBN 13 978-92-4-154785-7. [Google Scholar]
  5. Aflaki, A.; Mahyuddin, N.; Mahmoud, Z.-C.; Rizal, M. A review on natural ventilation applications through building façade components and ventilation openings in tropical climates. Energy Build. 2015, 111, 86–99. [Google Scholar] [CrossRef]
  6. Rysanek, A.; Murray, P.; Pantelic, J.; Clayton, M.; Meggers, F.; Schlueter, A. The design of a decentralized ventilation system for an office in Singapore: Key findings for future research. In Proceedings of the International Conference CISBAT 2015, Lausanne, Switzerland, 9–11 September 2015; pp. 812–815. [Google Scholar]
  7. Makhoul, A.; Ghali, K.; Ghaddar, N.; Chakroun, W. Investigation of particle transport in offices equipped with ceiling-mounted personalized ventilators. Build. Environ. 2013, 63, 97–107. [Google Scholar] [CrossRef]
  8. Ben-David, T.; Waring, M.S. Impact of natural versus mechanical ventilation on simulated indoor air quality and energy consumption in offices in fourteen U.S. cities. Build. Environ. 2016, 104, 320–336. [Google Scholar] [CrossRef]
  9. Thornton, B.A.; Wang, W.; Huang, Y.; Lane, M.D.; Liu, B. Technical Support Document: 50% Energy Savings for Small Office Buildings; USA Department of Energy: Richland, WA, USA, 2010. [Google Scholar]
  10. Mohamed, M.; Prasad, D.; Tahir, M.M. A study on balcony and its potential as an element of ventilation control in naturally ventilated apartment in hot and humid climate. In Proceedings of International Conference on Construction and Building Technology, Kuala Lumpur, Malaysia, 16–20 June 2008; pp. 173–180. [Google Scholar]
  11. Chen, J.; Augenbroe, G.; Song, X. Evaluating the potential of hybrid ventilation for small to medium sized office buildings with different intelligent controls and uncertainties in US climates. Energy Build. 2018, 158, 1648–1661. [Google Scholar] [CrossRef]
  12. Orme, M. Estimates of the energy impact of ventilation and associated financial expenditures. Energy Build. 2001, 33, 199–205. [Google Scholar] [CrossRef]
  13. Seppanen, O.; Fisk, W.J.; Lei, Q.H. Ventilation and performance in office work. Indoor Air 2006, 16, 28–36. [Google Scholar] [CrossRef] [PubMed]
  14. Priyadarsini, R.; Cheong, K.W.; Wong, N.H. Enhancement of natural ventilation inhigh-rise residential buildings using stack system. Energy Build. 2004, 36, 61–71. [Google Scholar] [CrossRef]
  15. Al-Tamimi, N.; Fadzil, S.F.S. Energy-efficient envelope design for high-rise resi-dential buildings in Malaysia. Archit. Sci. Rev. 2012, 55, 119–127. [Google Scholar] [CrossRef]
  16. Crosby, S.; Rysanek, A.M. Towards Improved Thermal Comfort Predictions for Building Controls: Hierarchical Bayesian Modelling of Indoor Environmental Design Conditions. In Proceedings of the 8th ACM International Conference on Systems for Energy-Efficient Buildings, Cities, and Transportation, Coimbra, Portugal, 17–18 November 2021; ACM: New York, NY, USA, 2021. [Google Scholar]
  17. Prajongsan, P.; Sharples, S. Enhancing natural ventilation, thermal comfort and energy savings in high-rise residential buildings in Bangkok through the use of ventilation shafts. Build. Environ. 2012, 50, 104–113. [Google Scholar] [CrossRef]
  18. Yuan, Y.; Luo, Z.; Liu, J.; Wang, Y.; Lin, Y. Health and economic benefits of building ventilation interventions for reducing indoor PM2.5 exposure from both indoor and outdoor origins in urban Beijing, China. Sci. Total. Environ. 2018, 626, 546–554. [Google Scholar] [CrossRef] [PubMed]
  19. Rackes, A.; Waring, M.S. Using multiobjective optimisations to discover dynamic building ventilation strategies that can improve indoor air quality and reduce energy use. Energy Build. 2014, 75, 272–280. [Google Scholar] [CrossRef]
  20. Allard, F. Natural Ventilation in Buildings. A Design Handbook; European Commission ALTENER Programme: London, UK, 1998. [Google Scholar]
  21. Quang, T.N.; He, C.; Morawska, L.; Knibbs, L.D. Influence of ventilation and filtration on indoor particle concentrations in urban office buildings, Atmos. Environment 2012, 79, 41–52. [Google Scholar]
  22. Mendell, M.J.; Eliseeva, E.A.; Davies, M.M.; Spears, M.; Lobscheid, A.; Fisk, W.J.; Apte, M.G. Association of classroom ventilation with reduced illness absence: A prospective study in California elementary schools. Indoor Air 2013, 23, 515–528. [Google Scholar] [CrossRef] [PubMed]
  23. Fisk, W.J. The ventilation problem in schools: Literature review. Indoor Air 2017, 27, 1039–1051. [Google Scholar] [CrossRef] [PubMed]
  24. Weschler, C.; Shields, H.C. Potential reactions among indoor pollutants. Atmos. Environ. 1997, 31, 3487–3495. [Google Scholar] [CrossRef]
  25. Al-Shaali, R.K. Tools for Natural Ventilation in Architecture. Ph.D. Thesis, University of California, Los Angeles, CA, USA, 2006; p. 169. [Google Scholar]
  26. Hyo, J.K.; Young, H.C. A study on a control method with a ventilation. requirement of a VAV system in multi-zone. Sustainability 2017, 9, 2066. [Google Scholar] [CrossRef]
  27. Klimatbyrån. BRG Product Katalog. Available online: http://www.klimatbyran.se/MediaBinaryLoader.axd?MediaArchive_FileID=22b1f060-f90c-47b0-a8f8d07a1c51daa9&MediaArchive_ForceDownload=True&Time_Stamp=637249512080494866 (accessed on 18 April 2021).
  28. Nyman, M.; Simonson, C. Life cycle assessment of residential ventilation units in a cold climate. Build. Environ. 2005, 40, 15–27. [Google Scholar] [CrossRef]
  29. Zhang, Y.; Wang, X.; Hu, E. Optimization of night mechanical ventilation strategy in summer for cooling energy saving based on inverse problem method. Proc. Inst. Mech. Eng. Part A J. Power Energy 2018, 232, 1093–1102. [Google Scholar] [CrossRef]
  30. Klimatbyrån. CDB Ljuddämpare Produktkatalog. Available online: http://www.klimatbyran.se/web/CDB.aspx (accessed on 17 April 2021).
  31. Gan, G.; Riffat, S.B. Naturally ventilated buildings with heat recovery: CFD simulation of thermal environment. Build. Serv. Eng. Res. Technol. 1997, 18, 67–75. [Google Scholar] [CrossRef]
  32. Manz, H.; Huber, H. Experimental and numerical study of a duct/heat exchanger unit for building ventilation. Energy Build. 2000, 32, 189–196. [Google Scholar] [CrossRef]
  33. Coydon, F.; Herkel, S.; Kuber, T.; Pfafferott, J.; Himmelsbach, S. Energy performance of façade integrated decentralised ventilation systems. Energy Build. 2015, 107, 172–180. [Google Scholar] [CrossRef]
  34. Fadaei, A. Ventilation systems and COVID-19 spread: Evidence from a systematic review study. Eur. J. Sustain. Dev. Res. 2021, 5, em0157. [Google Scholar] [CrossRef]
  35. Elsaid, A.M.; Ahmed, M.S. Indoor air quality strategies for air-conditioning and ventilation systems with the spread of the global coronavirus (COVID-19) epidemic: Improvements and recommendations. Environ. Res. 2021, 199, 111314. [Google Scholar] [CrossRef] [PubMed]
  36. Knibbs, L.D.; Morawska, L.; Bell, S.C.; Grzybowski, P. Room ventilation and the risk of airborne infection transmission in 3 health care settings within a large teaching hospital. Am. J. Infect. Control. 2011, 39, 866–872. [Google Scholar] [CrossRef] [PubMed]
  37. Won, D.; Yang, W. The State of-the-Art in Sensor Technology for Demand-Controlled Ventilation; Institute for Research in Construction, National Research Council Canada: Ottawa, ON, Canada, 2015. [Google Scholar]
  38. Seong, N.C.; Hong, S.M.; Yoon, D.W. Energy requirements of a multi-sensor based demand control ventilation system in residential buildings. In Proceedings of the 31st AIVC Conference Low Energy and Sustainable Ventilation Technologies for Green Buildings, Seoul, Korea, 26–28 October 2010. [Google Scholar]
  39. Kamendere, E.; Zandeckis, A.; Kamenders, A.; Ikaunieks, J.; Rochas, C. Mechanical ventilation with heat recovery system in renovated apartment buildings. Agron. Res. 2014, 12, 491–498. [Google Scholar] [CrossRef]
  40. Fernández-Seara, J.; Diz, R.; Uhía, F.J.; Dopazo, A.; Ferro, J.M. Experimental analysis of an air-to-air heat recovery unit for balanced ventilation systems in residential buildings. Energy Convers. Manag. 2011, 52, 635–640. [Google Scholar] [CrossRef]
  41. Fisk, W.J.; Mendell, M.J.; Davies, M.; Eliseeva, E.; Faulkner, D.; Hong, T.; Sullivan, D.P. Demand controlled ventilation and classroom ventilation; U.S. Department of Energy: Washington, DC, USA, 2012. [Google Scholar]
  42. Luongo, J.C.; Fennelly, K.P.; Keen, J.A.; Zhai, Z.J.; Jones, B.W.; Miller, S.L. Role of mechanical ventilation in the airborne transmission of infectious agents in buildings. Indoor Air 2016, 26, 666–678. [Google Scholar] [CrossRef] [PubMed]
  43. Fisk, W.J.; Sullivan, D.P.; Faulkner, D.; Eliseeva, E. CO2 Monitoring for Demand Controlled Ventilation in Commercial Buildings; California Energy Commission: Sacramento, CA, USA, 2010. [Google Scholar]
  44. Brandemuehl, M.; Braun, J. The impact of demand-controlled and economizer ventilation strategies on energy use in buildings. J. Eng. 1999, 105, 39. [Google Scholar]
  45. European Ventilation Industry Association. 2021. Available online: https://www.evia.eu/ (accessed on 12 November 2021).
  46. Yuan, F.D.; You, S.J. CFD simulation and optimization of the ventilation for subway side-platform. Tunn. Undergr. Space Technol. 2007, 22, 474–482. [Google Scholar] [CrossRef]
  47. Niemelä, T.; Vuolle, M.; Kosonen, R.; Jokisalo, J.; Salmi, W.; Nisula, M. Dynamic Simulation Methods of Heat Pump Systems as a Part of Dynamic Energy Simulation of Buildings. Available online: http://www.ibpsa.org/proceedings/BSO2016/p1146.pdf (accessed on 28 October 2021).
  48. WHO. New Global WHO Guidelines for Indoor Air Quality: InefficientlyBurning Solid Fuels Damages Health and Climate. 2014. Available online: http://www.euro.who.int/en/health-topics/environment-and-health/air-quality/news/news/2014/11/new-global-who-guidelines-for-indoor-air-quality-inefficiently-burning-solid-fuels-damages-health-and-climate (accessed on 15 November 2021).
  49. EPA. Improving Indoor Air Quality. 2016. Available online: https://www.epa.gov/indoor-air-quality-iaq/improving-indoor-air-quality, (accessed on 15 October 2021).
  50. Liu, P.-C.; Lin, H.-T.; Chou, J.-H. Evaluation of buoyancy-driven ventilation in atrium buildings using computational fluid dynamics and reduced-scale air model. Build. Environ. 2009, 44, 1970–1979. [Google Scholar] [CrossRef]
  51. Shilei, L.; Bin, L.; Xinhua, L.; Xiangfei, K.; Wei, J.; Lu, W. Performance analysis of PCM ceiling coupling with earth-air heat exchanger for building cooling. Materials 2020, 13, 2890. [Google Scholar] [CrossRef]
  52. Zampori, L.; Saouter, E.; Schau, E.; Cristobal, G.J.; Castellani, V.; Sala, S. Guide for Interpreting Life Cycle Assessment Result; Publications Office of the European Union: Luxembourg, 2016. [Google Scholar]
  53. Giama, E.; Papadopoulos, A. Benchmarking carbon footprint and circularity in production processes: The case of stonewool and extruded polysterene. J. Clean. Prod. 2020, 257, 120559. [Google Scholar] [CrossRef]
  54. Sandberg, M.; Moshfegh, B. Ventilated-solar roof air flow and heat transfer investigation. Renew. Energy 1998, 15, 287–292. [Google Scholar] [CrossRef]
  55. Giama, E.; Morsnik-Georgali, F.Z. Environmental impact assessment, environmental assessment of renewable energy conversion technologies. Sol. Energy Syst. 2021, in press.
  56. Xie, Z.; Du, L.; Lv, X.; Wang, Q.; Huang, J.; Fu, T.; Li, S. Evaluation and analysis of battery technologies applied to grid-level energy storage systems based on rough set theory. Trans. Tianjin Univ. 2020, 26, 228–235. [Google Scholar] [CrossRef]
Table 1. State-of-the-art on ventilation system applications in buildings in terms of energy efficiency, indoor air quality, and environmental impact assessment.
Table 1. State-of-the-art on ventilation system applications in buildings in terms of energy efficiency, indoor air quality, and environmental impact assessment.
ReferenceVentilation SystemType of Ventilation System Type of BuildingTarget of the System Installed
[5]Natural ventilationOpenings, air pressureResidential and office buildingsEnergy efficiency, energy consumption
[6]Mechanical ventilation,
decentralized units, chilled ceilings
Decentralized units, chilled
ceilings
OfficeEnergy efficiency, energy consumption
[7]Mechanical ventilationVariable air volume (VAV)
systems
OfficeEnergy efficiency, energy consumption
[8]Mechanical ventilationVariable air volume (VAV)
systems
OfficeEnergy efficiency, energy consumption, 22–33% reduced environmental impact
[9]Hybrid ventilation systemsNatural ventilation in combination with variable air volume systemsOfficeEnergy efficiency, energy consumption, in combination with PV system
[10]Natural ventilationOpenings, air pressureSchoolEnergy efficiency
[11]Hybrid ventilationRecovery (VAV) active supply diffuser and natural ventilationOfficeEnergy efficiency, energy consumption, in combination with Photovoltaic (PV) system
[12]Mechanical ventilationVariable air volume (VAV) systemsOfficeEnergy efficiency and cost effectiveness
[13]Mechanical ventilation and Hybrid ventilation systemsNAOfficeIndoor air quality
[14]Natural ventilationOpenings, air pressureResidentialIndoor air quality
[15]Natural ventilationOpenings, air pressureResidentialIndoor air quality
[16]Mechanical ventilationModel development for pollutants concetrationAll type of buildingsIndoor air quality and thermal comfort
[17]Natural VentilationAir pressure, passive coolingResidentialEnergy efficiency, reduction of the energy consumption and thermal comfort
[18]VentilationNatural, HybridNAIndoor air quality focused on PMs
[19]VentilationNAAll type of buildingsIndoor air quality and reduction of energy consumption
[20]Natural ventilationThe significance of the building design, openings, air pressure and volumeAll type of buildingsIndoor air quality
[21]Mechanical ventilationThe role of filtration to the systemOfficeIndoor air quality
[22]Natural ventilationOpenings, air pressureSchoolIndoor air quality
[23]Mechanical ventilationVariable air volume (VAV) systems, air filtrationSchoolIndoor air quality, emphasis to PMs and operational cost reduction
[24]Hybrid ventilationNatural ventilation in combination with mechanical componentsNAIndoor air quality
[25]Natural ventilationOpenings and architecture designOfficeIndoor air quality
[26]Mechanical ventilationVariable air volume (VAV) systemsOfficeEnvironmental impacts material use for the air supply unit
[27]Mechanical ventilationVariable air volume (VAV) systemsOfficeEnvironmental impacts material use for the air exhaust units
[28]Mechanical ventilationVariable air volume (VAV) systemsResidentialEnvironmental impacts
[29]Hybrid ventilationEmphasis to night ventilation benefits in summerResidentialEnergy efficiency, reducing cooling loads
[30]Mechanical ventilationVariable air volume (VAV) systemsOfficeEnvironmental impacts material use for the silencer
[31]Natural ventilationHeat recoveryAll type of buildingsEnergy efficiency in buildings
[32]Mechanical ventilationDuct/heat exchanger unit experimental applicationAll type of buildingsIndoor air quality and energy efficiency in buildings
[33]Mechanical ventilationdecentralized ventilation systems.All type of buildingsIndoor air quality and energy efficiency in buildings
[34]Mechanical ventilationMechanical ventilation systems in collaboration with natural ventilationAll type of buildingsIndoor air quality
[35]Ventilation technologies, mechanical as well as natural ventilationHybrid ventilation technologies for residential and non-residential buildingsNon residentialIndoor air quality
[36]Mechanical ventilationNon-residential applicationsNon residentialIndoor air quality airborne infection transmission
[37]Mechanical ventilationSensor Technology for demand-controlled ventilationAll type of buildingsEnergy efficiency and indoor air quality
[38]Hybrid ventilation systemLow energy and ventilation technologiesAll type of buildingsEnergy efficiency and environmental impact
[39]Mechanical VentilationHeat recovery system residential buildingsResidentialEnergy efficiency
[40]Mechanical ventilationHeat recovery system residential buildingsResidentialEnergy efficiency
[41]Mechanical ventilationDemand-controlled ventilation technology (DCV) for controlling air flow rates Application in office and school buildingsOffice and school buildingIndoor air quality and thermal comfort
[42]Mechanical ventilationThe role of mechanical ventilation in indoor environments and the effect on certain pollutantsAll type of buildingsIndoor air quality focused on airborne pathogen transmission
[43]Mechanical ventilationMechanical ventilation in commercial buildingsCommercialEnergy efficiency
[44]MechanicalThe impact of demand-controlled and economizer ventilation in buildingsAll type of buildingsEnergy efficiency
Table 2. Technical characteristics of PVs.
Table 2. Technical characteristics of PVs.
Characteristics Dimensions
External dimensions of the system1.58 × 664 mm2
Thickness38 mm
Weight117 kg
Front cover3.2 mm of tempered glass
Dimension of the junction boxes60 × 60 × 11.5 mm2
Cable lengths200/300 mm
Table 3. Technical characteristics of ventilation system.
Table 3. Technical characteristics of ventilation system.
Basic ComponentsType and Number of Items
Air fanCross flow, 3 items
Arduino board3 items
Arduino data loggerShield with RTCV1, 3 items
Dimmer module50–60 Hz for Arduino, 3 items
Power supply12VDC, 3 items
SensorsDS18820
Table 4. Environmental impact assessment results validation for ventilation system applications in buildings.
Table 4. Environmental impact assessment results validation for ventilation system applications in buildings.
Impact CategoriesGiama (2021) SC3 Impact Results (Table 5)Nilsson (2020) Impact Results [56]
Climate Change (kg CO2-Eq/m2)248.4164,375
Ozone Depletion (kg CFC-11-Eq/m2)0.0010.000001
Acidification (kg SO2-Eq/m2)118.66155
Eutrophication (kg NOx-Eq/m2)9.698.3
Photochemical Oxidation (kg ethylene-Eq/m2)0.880.1
Table 5. Environmental impact assessment results for different construction scenarios and systems in non-residential buildings.
Table 5. Environmental impact assessment results for different construction scenarios and systems in non-residential buildings.
StageSC1 Conventional Operation (No MV, No RES)
Acidification (kg SO2-Eq/m2)Climate Change (kg CO2-Eq/m2)Depletion of Abiotic Sources (kg Antimony-Eq/m2)Eutrophication (kg NOx-Eq/m2)FAETP-100a (kg 1,4-DCB-Eq/m2)Human Toxicity (kg 1,4-DCB-Eq/m2)Radiation (DALYs/m2)MAETP-100a (kg 1,4-DCB-Eq/m2)Photochemical Oxidation (kg Ethylene-Eq/m2)Ozone Depletion (kg CFC-11-Eq/m2)TAETP-100a (kg 1,4-DCB-Eq/m2)
Construction0.12779.9 × 10−50.30.010.600.680.00086 × 10−70.07
Use15090.47.9611.518.9527292.3 × 10−51565.51.11.3 × 10−33.97
Transportation0.01120.0140.0180.0510.374 × 10−90.380.00052.7 × 10−70.0003
Total150.1169.57.9811.8219.022730.52.3 × 10−51566.61.111.3 × 10−34.04
StageSC2 PV Installation (No MV)
Acidification (kg SO2-Eq/m2)Climate Change (kg CO2-Eq/m2)Depletion of Abiotic Sources (kg Antimony-Eq/m2)Eutrophication (kg NOx-Eq/m2)FAETP-100a (kg 1,4-DCB-Eq/m2)Human Toxicity (kg 1,4-DCB-Eq/m2)Radiation (DALYs/m2)MAETP-100a (kg 1,4-DCB-Eq/m2)Photochemical Oxidation (kg Ethylene-Eq/m2)Ozone Depletion (kg CFC-11-Eq/m2)TAETP-100a (kg 1,4-DCB-Eq/m2)
Construction0.65175.254.740.6222.56129.710−694.540.0089.92 × 10−60.11
Use12776.566.749.7416.123112 × 10−51325.40.931.1 × 10−33.4
Transportation0.0112.10.0150.0190.0530.384.5 × 10−90.390.00052.8 × 10−70.0003
Total127.7253.961.510.438.724412.1 × 10−51420.40.941.1 × 10−33.51
StageSC3 PV Installation and MV
Acidification (kg SO2-Eq/m2)Climate Change (kg CO2-Eq/m2)Depletion of Abiotic Sources (kg Antimony-Eq/m2)Eutrophication (kg NOx-Eq/m2)FAETP-100a (kg 1,4-DCB-Eq/m2)Human Toxicity (kg 1,4-DCB-Eq/m2)Radiation (DALYs/m2)MAETP-100a (kg 1,4-DCB-Eq/m2)Photochemical Oxidation (kg Ethylene-Eq/m2)Ozone Depletion (kg CFC-11-Eq/m2)TAETP-100a (kg 1,4-DCB-Eq/m2)
Construction0.65175.254.740.6222.56129.710−694.540.0089.92 × 10−60.11
Use118.071.16.269.0514.922147.11.8 × 10−51231.550.8710−33.15
Transportation0.012.10.010.020.050.44.5 × 10−90.390.0012.78 × 10−70
Total118.66248.4619.6937.532277.21.9 × 10−51326.480.8810−33.26
Table 6. Percentage contribution of life cycle stages to environmental impact of SC3 (ventilation systems are included).
Table 6. Percentage contribution of life cycle stages to environmental impact of SC3 (ventilation systems are included).
StageAcidification (kg SO2-Eq/m2)Climate Change (kg CO2-Eq/m2)Depletion
of Abiotic Sources (kg Antimony-Eq/m2)
Eutrophication (kg NOx-Eq/m2)FAETP-100a (kg 1,4-DCB-Eq/m2)Human Toxicity (kg 1,4-DCB-Eq/m2)Radiation (DALYs/m2)MAETP-100a (kg 1,4-DCB-Eq/m2)Photochemical Oxidation (kg Ethylene-Eq/m2)Ozone Depletion (kg CFC-11-Eq/m2)TAETP-100a (kg 1,4-DCB-Eq/m2)
Construction0.5%70.53%89.72%6.4%60.1%5.7%5.26%7.13%0.9%0.99%3%
Use99.4%28.62%10.26%93.4%39.8%94.29%94.71%92.84%99.0%98.98%97%
Transportation0.01%0.85%0.02%0.2%0.1%0.018%0.02%0.03%0.1%0.03%0%
Total100%100%100%100%100%100%100%100%100%100%100%
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Back to TopTop