HVAC equipment Research Papers - Academia.edu (original) (raw)

This paper analyses the energy and economic performance of roof and/or façades Building Integrated flat-plate PhotoVoltaic and Thermal (BIPVT) collectors for residential applications. Aim of the analysis is to assess the active and passive effects due to the building integration of solar technologies on the building energy consumptions. In particular, a comparison among innovative building-plant system configurations, based on BIPVT collectors for the simultaneous production of electricity, thermal energy, and domestic hot water, is carried out. The simulation models of the proposed system layouts are designed and implemented in TRNSYS simulation environment for the dynamic assessment of their energy and economic performance. By means of the developed simulation model, the occurring summer and winter building passive energy effects due to the PVT building integration are also analysed.
Several case studies are developed by modelling a representative multi-storey residential building and by taking into account different European climates. For such case studies a suitable energy parametric analysis is performed by varying the thermal resistances and capacitances of the building envelope. By the simulation results interesting design and economic feasibility guidelines are obtained. In particular, by varying the weather location and the building-plant configuration, the adoption of BIPVT panels produces a decrease of the primary energy demands from 67 to 89%. The passive effects of the BIPVT system in both the winter and summer season are also assessed for all the investigated climate zones. The calculated economic profitability resulted slightly better for roof BIPVT panels than for roof and façade applications. For the investigated case studies, the pay back periods appear quite long, varying from 11 years for South European weather zones to 20 for North European ones.

- by and +2
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- Renewable Energy, Sustainable Building Design, Energy Efficiency Buildings, Building Energy Simulation
- by Pietro Mazzei
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- Mechanical Engineering, Chemical Engineering, Energy, Energy Efficiency Buildings

Due to its considerable impact on climate, bus air conditioning systems are being pushed to take a new and sustainable path. Electric buses relying on transcritical CO2 air conditioning units are perceived to be eco-friendly and future-proof solutions to achieving such a target. However, in order to have highly efficient air conditioning systems, the CO2 charge needs to be optimized. In this paper the energy and exergy-based analyses were performed to investigate the effect of normalized refrigerant charge on the system performance by using a test rig of a transcritical CO2 air conditioning unit for an 8 m electric bus. Results showed that the normalized refrigerant charge range of 0.248~0.336 was recommended in order to ensure the maximum coefficient of performance (COP). In addition, in sufficient charge conditions, the optimal COP, cooling capacity and exergy efficiency were 1.716, 18.97 kW and 29.79%, respectively, under the standard refrigeration condition of 35 °C/27 °C. As the ambient temperature rose from 35 °C to 40 °C, the COP, cooling capacity and exergy efficiency decreased by 16.03%, 10.90% and 12.22%, respectively. Furthermore, the exergy efficiency was found not to be sensitive to slightly insufficient charge, whereas overcharge was observed to be even beneficial to exergy efficiency under the condition of ensuring the maximum COP. In addition, insufficient refrigerant charging seriously affected the irreversible losses in the indoor and outdoor heat exchangers, whereas slight overcharge had little effect on the component exergy efficiency. Finally, the need to improve the CO2 compressor efficiency to enhance the system performance was revealed.

Refrigeration and Air Conditioning Lectures

- by Majd Hammad
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- Heat Transfer, Hvac System, Mechanical Engineering-HVAC, HVAC equipment

Variable Refrigerant Flow (VRF) systems are refrigerant systems, which are generally comprised of an outdoor unit serving multiple indoor units connected by a refrigerant piping network. It is important to evaluate the performance of VRF systems, which can help the design and operate of VRF systems. Performance test done by manufactory can reveal the performance of VRF systems in designed conditions. However, it is hard to reveal effective performance in real buildings. The field test is complicated compared with the test in the laboratory and can only conduct on typical samples rather than large scale samples. However, typical samples are not enough for reflecting the performance of large scale VRF systems samples. A simple method of evaluating the performance of large scale VRF systems samples is necessary. This paper proposed and calculating model for electricity consumption and cooling demand of VRF systems based on measured operating data in the laboratory. The paper used the calculating model combined with 344 samples operating data from real residential buildings to calculate the performance of a large scale VRF. This paper analyzed the VRF systems' performance with different influencing factors such as climate zones, cooling duration and outdoor temperature for the recommendation for VRF systems' designing and operation. 1. Introduction Space cooling demand in the world has increased dramatically in these years because of climate change, urbanization, and economy development [1]. Therefore, the performance of the HVAC system for space cooling is very important and necessary to be improved [2][3]. Variable Refrigerant Flow (VRF) systems are HVAC systems, which are generally comprised of an outdoor unit serving multiple indoor units connected by a refrigerant piping network. VRF systems are widely used in residential buildings and office buildings in China. It is important to evaluate the performance of VRF systems, which can help the design and operate of VRF systems. The performance of VRF systems is influenced by many factors, such as operating mode and climate [4]. The methods of evaluating the performance of VRF systems are mainly performance test by manufactory in laboratory and field test on typical samples. The performance test by manufactory can reveal the performance of VRF systems in all the conditions [5]. However, it is hard to represent the main conditions of systems and cannot reveal the real performance in real buildings. In fact, the field test is complicated compared with the test in the laboratory and can only conduct on typical samples rather than large scale samples. The typical samples are not enough for reflecting the performance of large scale VRF systems samples. The main method of evaluating the performance of VRF systems are a physical model [6,7] and data-driven model [8,9]. The physical model required many detailed factors, which may not be able to test in real buildings. The data-driven model required much more data for model training [10]. A simple method of evaluating the performance of large scale VRF systems samples is necessary. Previous research has already proposed a hybrid model for evaluating VRF systems in office buildings [11]. The evaluation for VRF systems in residential buildings is also important. Therefore, this paper proposed a hybrid model for electricity consumption

The goal of this chapter is to provide an overview of the current understanding of the concepts of Zero Energy Building (ZEB) and Nearly Zero Energy Building (nZEB). The chapter discusses the current definitions of these concepts as well their design and assessment methodologies. The chapter is based on a literature review of national action plans as well as international policies and standards. While a broad global overview of the concepts of ZEB and nZEB is targeted, a significant portion of this chapter deals specifically with documents produced in Europe where the challenges about the goals set by the Energy Performance of Building Directive (EPBD) recast are leading to discuss topics such as the energy balance methodologies, boundaries of ZEB and nZEB, type and energy sources to consider, homogenization techniques for different energy carriers and energy balance indicators. This chapter shows that an agreement towards common definitions of ZEB and nZEB is progressive, but differences among the several interpretations given worldwide still exist.

Presentation of HVAC Design of a building based on Indian Student Technical League (ISTL)

Space cooling energy consumption is a significant component of building energy consumption, and in recent years it has attracted much attention worldwide owing to its significantly increasing usage. The variable refrigerant flow (VRF) system is one common type of cooling equipment for buildings in China and is applied extensively to residential and office buildings. The performance of VRF systems significantly influences the cooling energy consumption of buildings. The system energy efficiency and electricity consumption are the main indicators employed to evaluate the performance of VRF systems. It is hard to obtain the actual energy efficiency and electricity consumption of VRF systems in buildings because of the high cost of the required complicated measurements. This study proposes a virtual sensor modeling method to determine the actual energy efficiency and electricity consumption of 344 VRF systems in residential buildings. Statistical and clustering analyses are conducted to determine the energy efficiency and electricity consumption to obtain distributions and typical operation load patterns of VRF systems in residential buildings in China. The main findings are as follows: the main range of the Seasonal Energy Efficiency Ratio (SEER) for the cooling season is from 2.9 to 4.4; the median SEER in the Hot Summer and Cold Winter zone is lower than in another climate zones; the longer cooling duration may lead to greater electricity consumption, and the electricity load for VRF systems electricity load is periodic for each day. The oversizing issue is common for VRF systems in the dataset, which also led to the lower energy efficiency of VRF systems. The high usage of VRF systems appeared from July 27th to August 26th. The findings provide recommendations for designing VRF systems in residential buildings. Keywords variable refrigerant flow (VRF), energy efficiency, virtual sensor, residential building Article History

Analytical method validation is an important requirement to support the package of information submitted to international regulatory agencies in support of new product marketing or clinical trials applications. Back in 1987, the US Food and Drug Administration (FDA) issued its first guidance on analytical methods. The document was subsequently revised in 2000 and, despite the advancement in analytical methods, there were no further updates until 2014, when a new draft was issued for public comment. Following the period of review, in July 2015, the FDA issued a new version of the guidance. The third edition is titled Analytical Procedures and Methods Validation for Drugs and Biologics.

- by Tim Sandle
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- Chemistry, Analytical Chemistry, Science Education, Measurement and Evaluation

The cleanliness of changing rooms used to access pharmaceutical cleanroom facilities is of considerable importance. This ensures that the changing environment and the act of putting on cleanroom suits do not generate high levels of contamination; for such contamination might be carried on personnel leaving changing areas and into the process areas. Furthermore, it is important to avoid the transfer of contamination to the outside of the garment during the gowning process. A study was undertaken to assess the levels of airborne contamination in a changing room during use. To assess this, a changing room was examined under different conditions: at-rest; occupied (with different numbers of personnel); and post-use. For the assessment, a novel rapid microbiological method was used. The assessment of microbiological air quality within changing rooms is conventionally undertaken using methods which rely upon microbial growth media. Due to incubation times, several days are required to ascertain the contamination level risk. This paper describes the use of an alternative real-time continuous monitoring system (the BioVigilant IMD-A® System), based on optical spectroscopy. The paper concludes that increasing the numbers of personnel going through a changing room increases the level of airborne biological activity and increases the length of time required for the room to recover. The study also demonstrates the usefulness of the rapid microbiological method.

- by Tim Sandle and +1
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- Microbiology, Environmental microbiology, Particle Physics, Training and Development
- by samir rabia
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- HVAC equipment, HVAC / Building Services

Precision Equipment: Star Up,field work

- by Carlos Martinez
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- HVAC equipment
- by Manuel Garcia Saiza
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- HVAC equipment
- by samir rabia
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- HVAC and Sustainability, Hvac System, Mechanical Engineering-HVAC, HVAC equipment

This paper examines the design and operations of school's HVAC. These systems are liable for a main component of overall institutional energy consumption. The right size HVAC handles space and equipment heating and cooling loads, and adjusts the air supply technology to stand the exact forecast heating and cooling loads of theschool building.This paper discusses full details of designing an air supply technique to convey the right amount of air into space. HVAC design depends on the location, view and construction of the building. It also explains the social implications and hoped that HVAC designers and those involved in the construction industry will have a best knowledge of green school buildings and use efficient approaches and technologies for this purpose.

- by Jacob Antony
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- Thermal Engineering, Robotics, Automation, HVAC and Sustainability

Single zone (SZ) air handling units (AHUs) are widely applied in the conditioned spaces. A SZ AHU typically consists of a chilled water cooling coil, a hot water heating coil, and a supply fan. For a constant volume (CV) SZ AHU or variable air volume (VAV) SZ AHU operating at a minimum airflow, the control valve of either the cooling coil or heating coil is modulated to vary the supply air temperature and consequently control space air temperature. Traditionally, a single control loop is applied to modulate the control valve directly based on the space air temperature. The traditional control is simplistic in nature, however, suffers significant drawbacks. Due to the thermal capacity of both the water in the coils and the air in the conditioned space, the system often becomes unstable due to nonlinear characteristics of the SZ AHU system and leads to hunting of the control valve. On the other hand, cascade control makes the control system more adaptive and robust. A cascade control can be applied to a SZ AHU in order to stabilize the system. The primary controller reads the room air temperature and determines the required supply air temperature for a secondary controller which then controls the heating/cooling coil valve. The purpose of this paper is to demonstrate the stability of the cascade control method in a SZ AHU system. A model of the SZ AHU system with transfer functions is developed for conventional and cascade control methods and root-locus analysis is performed. The results conclude that the cascade control improves the stability of the control valve by reducing the sensitivity to the change in the operating conditions.

- by Joey Anderson
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- HVAC equipment

In this paper, a novel purposely designed dynamic simulation model for the performance analysis of solar heating and cooling systems is presented. The investigated system layouts are based on single stage LiBr–H2O absorption chillers and on both evacuated tube and concentrating photovoltaic thermal solar collectors. Furthermore, both electric chiller and gas fired heater backup system are considered. Such model is implemented in a computer code written in MATLAB. Here, the optimisation of several system design and operating parameters in terms of energy saving is also carried out. A code to code analysis is performed comparing the obtained simulation results vs. those achieved by a TRNSYS model available in literature. The simulation code for the concentrating photovoltaic thermal solar collectors is validated by experimental data. A good agreement among results is observed in both the cases. A suitable case study referred to a building including both offices and dwellings located in Northern and Southern Italy is presented. High primary energy savings are obtained for some of the investigated system layouts. By evacuated tube collectors solar field such savings can reach 74%, while shifting to concentrating photovoltaic thermal solar collectors they often surpass 100%. The system economic profitability strongly depends on future scale economies and eventual public funding.

- by Adolfo Palombo and +1
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- Renewable Energy, Sustainable Building Design, Energy Efficiency Buildings, Building Energy Simulation
- by Vahid Vakiloroaya
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- Solar, Solar Energy, HVAC equipment, HVAC / Building Services

n prototype d’échangeur-stockeur pour le rafraîchissement de l’air a été conçu, dimensionné et réalisé pour être intégré dans un prototype de maison solaire à énergie positive. Ce prototype intègre une paraffine (Matériau à Changement de Phase -MCP-) dont la transition solide/liquide s’effectue aux alentours de 21°C. Des essais en conditions de laboratoire ont été conduits afin de dégager le comportement dynamique de l’échangeur-stockeur ; cet échangeur-stockeur a été soumis à des cycles de rafraichîssement (fonte du MCP) et de régénération (solidification du MCP) et ses performances ont été évaluées. Dans le cadre du développement d’un outil de modélisation de cet échangeur-stockeur, puis d’un outil d’aide à la décision pour de futurs prototypes de tels systèmes, les résultats expérimentaux obtenus ont été comparés aux résultats numériques issus de cet outil de modélisation. Cette comparaison a amené à l’affinage du modèle utilisé et de proposer des géométries de contenants de MCP.

Client was looking for a solution to enable BACnet MS/TP interface for its VFD drive in HVAC system. In addition, client also wanted support in minimizing the complexity in testing. Client selected SoftDEL for its BACnet stack development... more

Client was looking for a solution to enable BACnet MS/TP interface for its VFD drive in HVAC system. In addition, client also wanted support in minimizing the complexity in testing.
Client selected SoftDEL for its BACnet stack development and testing expertise.

- by SoftDEL Systems
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- HVAC modelling, HVAC Control, HVAC equipment, energy efficient HVAC design

- by Jacob Antony and +1
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- Thermal Engineering, Robotics, Automation, HVAC and Sustainability

In this paper, a purposely designed code for the performance analysis of the Water Loop Heat Pump (WLHP) systems is presented. Hourly, daily and seasonal energy system consumptions, operating economic costs and environmental impact assessments are dealt with. For the scope of comparison, the performances of two reference HVAC system are investigated too. For the computation of the building heating and cooling requirements, a suitable dynamic performance simulation model is being developed.
All the relevant algorithms are implemented in MATLAB�. A case study of an office building undergoing simulation in different European climatic areas is being presented. Here, different building thermal features are considered. In order to maximize the system performance an additional optimization procedure to the operating devices temperatures is carried out. Results show that primary energy savings and avoided CO2 emissions of the WLHP system vary in relation to the compared reference systems and can be obtained only in several European weather zones. The feasibility of the WLHP system strongly depends on electricity and natural gas national costs.

Insecurity has been a challenge faced by developed and developing countries with Nigeria being a typical example. This work intends to adddress these problems using remote monitoring technique with geo-location facilities for real-time monitoring and tracking of security personnels and equipments. This paper presents a system that comprised of both hardware and software resources. The hardware resourses is based on a controller, a sensing block, a communication unit and power supply. The sensing unit whose major component is the Ublox Neo 6 Global Positioning System (GPS) module, captures the location after locking a minimum of four satellites, it then passes the location data to the controller (Arduino Uno Mini Pro). The controller interprets the data captured and send it as Short Message Service (SMS) through the communication unit (Sim 800L GSM module) to the administrator. A Graphic User Interface was developed to help the administrator interpret the location data received vi...

- by Samir Rabia
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- HVAC and Sustainability, Hvac System, Mechanical Engineering-HVAC, HVAC equipment

HVAC protective lanolin fluid lubricants sealers and greases for the overall protection of the equipment.

- by David Bouterey
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- HVAC and Sustainability, Mechanical Engineering-HVAC, HVAC equipment, HVAC systems

Energy Performance Index (EPI) is a parameter used to appraise and examine office, residential and commercial building energy efficiency during design, construction, renovation and operations. Similar buildings in North America and Europe have EPI of less than 150 kWh/sq m/year. Energy-conscious building design has been shown to reduce EPI to 100 to 150 kWh/sq m/year in India. However, this research indicates an EPI of between 21 to 41 kWh/sq m/year here in Nigeria. This gives an average of 31 kWh/sq m/year for the three (3) buildings studied. This low EPI is not unconnected with the fact that these Buildings lack HVAC equipment and other energy consuming devices that are required standards in developed and some developing regions. On the positive side, this low EPI indicates that the Carbon Emission Footprint of these buildings studied are low.

- by ADEMOLA JIMOH
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- Energy Conservation, Energy Audit, HVAC equipment, Office Productivity
- by Samir Rabia
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- HVAC and Sustainability, Hvac System, Mechanical Engineering-HVAC, HVAC equipment

- by Alvian Pambudi
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- Services Marketing and Management, Yogyakarta, HVAC and Sustainability, Surakarta

service coldstorage jawa tengah.
melayani jasa fabrikasi coldstorage, instalasi atau pemasangan coldstorage, air dryer, chiller, AHU HVAC

Outdoor airflow rate, building static pressure, supply air duct static pressure and relief air plenum static pressure, as controlled variables, are maintained by modulating the speed of the supply and return fans and the position of the outdoor, recirculating, and relief air dampers in an air handling unit (AHU). In practice, the three dampers are interlinked completely or partially to match independent control inputs with the controlled variables. The traditional damper control has all the three dampers interlinked with no control over the relief air plenum static pressure. The reverse relief airflow might occur as the outdoor air damper approaches the closed position. To prevent the reverse airflow, one of solutions is to decouple the relief air damper and maintain positive static pressure at the relief air plenum. Two control methods are available based on the control loop design. The first control method uses the return fan speed to control the relief air plenum static pressure and the relief air damper to control the building static pressure, while the second control method switches two control inputs. The purpose of this paper is to evaluate the controllability over the reverse relief airflow and building static pressure of these two control methods. The system performance is investigated through steady state simulation on an AHU at different outdoor airflow using a nonlinear network solution. The simulation results show that both the control methods can well prevent the reverse relief airflow. However, the first control method may result in negative building static pressure at lower outdoor airflow ratio and either excessively positive building static pressure or excessive return fan power at higher outdoor airflow ratio. On the other hand, the second control method shows the robustness on the building static pressure control.

- by Kaustubh Phalak
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- HVAC and Sustainability, HVAC Control, Hvac System, Mechanical Engineering-HVAC

In this paper the energy design and the optimization of a non-residential NZEB conceived for Mediterranean climates are discussed. The presented NZEB will be built up in Naples (South-Italy). The building will include offices, expo spaces and a conference room. Different innovative energy efficiency strategies, regarding the building envelope and plants are taken into account. Their benefit in terms of energy performance is assessed by a novel in-house developed building energy performance simulation code (DETECt 2.2) written in MatLab. An optimization procedure and a sensitivity analysis of the pivotal design and operating parameters are carried out from both the energy and economic points of view. The obtained numerical results show that interesting energy and economic savings can be achieved. Results can be useful for stakeholders working on non-residential NZEBs in temperate climates.

- by Annamaria Buonomano and +1
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- Renewable Energy, Sustainable Building Design, Energy Efficiency Buildings, Building Energy Simulation
- by Mustafa Falih
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- Engineering, Environmental Science, Air Quality, Indoor Air Quality
- by Samir Rabia
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- HVAC and Sustainability, Hvac System, Mechanical Engineering-HVAC, HVAC equipment
- by Ondrej Holub
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- HVAC equipment

This paper deals with European TRY weather data processing for climatic indexes generation, useful for HVAC energy and cost simplified evaluation. For nine Italian locations are presented: 99 and 2·5% dry bulb temperatures, 2·5% wet bulb temperatures, heating and cooling degree days, latent enthalpy days, unitary sensible and latent loads. TRY psychrometric data were processed according to a bin method that preserves the correlation between dry bulb temperature and moisture content, and then reduced by an averaging technique. An example is worked out in order to present an engineering shorthand for energy and cost evaluation of HVAC system.