Effective Mixed-Mode Ventilation System With Intermittent Personalized Ventilation for Improving Thermal Comfort in an Office Space

2020 ◽  
Author(s):  
Elvire Katramiz ◽  
Nesreen Ghaddar ◽  
Kamel Ghali
Keyword(s):  
Thermal Comfort ◽  
Control Strategy ◽  
Mixed Mode ◽  
Natural Ventilation ◽  
Energy Savings ◽  
Ventilation System ◽  
Energy Performance ◽  
Building Performance Simulation ◽  
Office Space ◽  
Personalized Ventilation

Abstract The mixed-mode ventilation (MMV) system is an energy-friendly ventilation technique that combines natural ventilation (NV) with mechanical air conditioning (AC). It draws in fresh air when the outdoor conditions are favorable or activates otherwise the AC system during occupancy hours. To improve performance of the MMV system, it is proposed to integrate it with an intermittent personalized ventilation (IPV) system. IPV delivers cool clean air intermittently to the occupant and enhances occupant thermal comfort. With the proper ventilation control strategy, IPV can aid MMV by increasing NV mode operational hours, and improve the energy performance of the AC system by relaxing the required macroclimate set point temperature. The aim of this work is to study the IPV+MMV system performance for an office space application in terms of thermal comfort and energy savings through the implementation of an appropriate control strategy. A validated computational fluid dynamics (CFD) model of an office space equipped with IPV is used to assess the thermal fields in the vicinity of an occupant. It is then coupled with a transient bio-heat and comfort models to find the overall thermal comfort levels. Subsequently, a building-performance simulation study is performed using Integrated Environmental Solutions-Virtual Environment (IES-VE) for an office in Beirut, Lebanon for the typical summer month of July. An energy analysis is conducted to predict the savings of the suggested design in comparison to the conventional AC system. Results showed that the use of IPV units and MMV significantly reduced the number of AC operation hours while providing thermal comfort.

scholarly journals Development of strategy for combined smart ventilated window and PCM energy storage control for residential building energy saving

2021 ◽  
Vol 2042 (1) ◽  
pp. 012161
Author(s):  
Yue Hu ◽  
Per Kvols Heiselberg
Keyword(s):  
Energy Storage ◽  
Thermal Comfort ◽  
Energy Saving ◽  
Control Strategy ◽  
Energy Savings ◽  
Control Strategies ◽  
Average Energy ◽  
Residential Building ◽  
Energy Performance ◽  
Before And After

Abstract The paper studies the energy renovation of a residential building with new façade solutions combining smart ventilated window (VW) and PCM energy storage and the corresponding control strategy to ensure energy savings. The study is carried out by Energyplus modelling comparing the energy consumption and thermal comfort of an apartment before and after renovation. A detailed control strategy is introduced and simulated. The modelling results of the apartment before and after retrofit indicate that with the designed control strategies, the average energy saving percentage of the apartment with PCM energy storage and VW compared to the apartment without PCM energy storage and VW is 29%. The rooms with PCMVWs achieve higher energy saving than the rooms with only VWs. The PCM energy storage improves energy performance of the VWs for both heating and cooling seasons. With the renovation, the thermal comfort of all the rooms are improved for cooling season.

The Application of Computer Simulations on one Commercial Building to Improve Energy Performance

2010 ◽  
Vol 171-172 ◽  
pp. 364-367
Author(s):  
Jia Fang Song
Keyword(s):  
Thermal Comfort ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Energy Performance ◽  
Comfort Level ◽  
Commercial Building ◽  
Simulation Tools ◽  
Output Performance ◽  
Support Software

This paper introduces the application of the TAS simulation support software to determine the energy performance in between a full mechanical ventilated building than that of a hybrid ventilated-- combined mechanical and naturally ventilated (atrium area to be naturally ventilated) building. A modeled three-storey commercial office building will be used as the main subject of this analysis. To determine the thermal comfort level of the central atrium, Parameters will be set in such a way that the full height windows will be 100% open. Results will be then tabularized to determine and analysis the output of the simulation. Recommendations will be then given based on the output performance of the building. In Tropics, it’s very difficult to achieve better thermal comfort in a naturally ventilated building. With the help of these simulation tools we can find whether natural ventilation is possible in this tropical climate in terms of thermal comfort, ventilation system and energy demand.

scholarly journals The Significance of the Adaptive Thermal Comfort Practice over the Structure Retrofits to Sustain Indoor Thermal Comfort

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2946
Author(s):  
Aiman Albatayneh ◽  
Mustafa Jaradat ◽  
Mhd Bashar AlKhatib ◽  
Ramez Abdallah ◽  
Adel Juaidi ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Savings ◽  
Ventilation System ◽  
Minimum Energy ◽  
Computer Software ◽  
Energy Performance ◽  
Building Envelope ◽  
Indoor Thermal Comfort ◽  
Adaptive Thermal Comfort

Any building’s design should sustain thermal comfort for occupants and promote less energy usage during its lifetime using accurate building retrofits to convert existing buildings into low-energy buildings so that the heating and cooling loads can be minimized. Regarding the methodology adopted in this research, an energy model of an educational building located at the German Jordanian University in Jordan was constructed utilizing DesignBuilder computer software. In addition, it was calibrated utilizing real energy consumption data for a 12-month simulation of energy performance. Subsequently, a computerized evaluation of the roles of building envelope retrofits or the adaptive thermal comfort limits in the reduction of the overall building energy consumption was analyzed. The results of the study show that the current building’s external wall insulation, roof insulation, glazing, windows, and external shading devices are relatively energy-efficient but with high cost, resulting in significant financial losses, even though they achieved noticeable energy savings. For instance, equipping the building’s ventilation system with an economizer culminated in the highest financial profit, contributing to an annual energy savings of 155 MWh. On the other hand, in an occupant-centered approach, applying the adaptive thermal comfort model in wider ranges by adding 1 °C, 2 °C, and 3 °C to the existing operating temperatures would save a significant amount of energy with the least cost (while maintaining indoor thermal comfort), taking over any retrofit option. Using different adaptive thermal comfort scenarios (1 °C, 2 °C, and 3 °C) led to significant savings of around 5%, 12%, and 21%, respectively. However, using different retrofits techniques proved to be costly, with minimum energy savings compared to the adaptive approach.

Thermal Comfort and Energy Savings in a Simulated Office Conditioned by a Transient Personalized Ventilator and a Displacement Ventilation System

2020 ◽  
Author(s):  
Douaa Al Assad ◽  
Kamel Ghali ◽  
Nesreen Ghaddar ◽  
Elvire Katramiz
Keyword(s):  
Thermal Comfort ◽  
Energy Savings ◽  
Ventilation System ◽  
Rate Of Change ◽  
Comfort Level ◽  
Thermal Manikin ◽  
Cfd Model ◽  
Displacement Ventilation ◽  
Additional Energy ◽  
Personalized Ventilation

Abstract The aim of this work is to evaluate the performance of an intermittent personalized ventilation (IPV) system assisting a displacement ventilation (DV) system to improve thermal comfort and save energy. This will be conducted by developing a transient 3D computational fluid dynamics (CFD) model of an occupied office space equipped with systems. The occupant is modeled by a heated thermal manikin replicating the human body. The CFD model is coupled with a transient bio-heat model to compute segmental skin temperatures and their rate of change. The latter are taken as input into Zhang’s comfort model to predict and overall thermal comfort. The model was used to conduct a case study, where the overall thermal comfort and energy savings will be assessed for the IPV + DV These results will be compared with those of steady personalized ventilation (PV) + DV and standalone DV systems. By varying the IPV frequency in the typical indoor range of [0.3 Hz – 1 Hz], it was found that the IPV + DV system was able to enhance comfort compared to steady PV + DV and a standalone DV. In addition, an energy analysis was conducted and it was shown that the IPV was able to achieve considerable energy savings compared to a steady PV + DV at the same thermal comfort level. Moreover, relaxing the DV supply temperature to higher occupied zone temperatures, can provide additional energy savings while still maintaining comfort levels in the space.

scholarly journals Experimental Data and Simulations of Performance and Thermal Comfort in a Typical Mediterranean House

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco
Keyword(s):  
Energy Efficiency ◽  
Thermal Comfort ◽  
Energy Demand ◽  
Natural Ventilation ◽  
Thermal Characterization ◽  
Energy Performance ◽  
Building Stock ◽  
Energy Demands ◽  
Dwelling House ◽  
Account Standard

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

scholarly journals THERMAL COMFORT AND ENERGY SOLUTIONS FOR A BETTER RESIDENTIAL ENVIRONMENT IN MALAYSIA

2015 ◽  
Vol 13 (5) ◽  
Author(s):  
Noor Aziah Mohd Ariffin
Keyword(s):  
Thermal Comfort ◽  
Air Conditioning ◽  
Energy Savings ◽  
Energy Performance ◽  
Data Monitoring ◽  
Medium Density ◽  
Design Strategies ◽  
Residential Energy ◽  
Passive Design ◽  
Design Systems

In hot-humid Malaysia, there are around five million units of housing. Among these, the medium-density terraced are the most built. However, little emphasis was given to designing for thermal comfort and energy efficiency. Consequently, air-conditioning is ubiquitous with ever-rising residential energy consumption. This paper studied passive design systems to improve living conditions and conserve energy through orientation and insulation parameters for terraced housing. Utilizing a triangulation of methods to correlate between thermal comfort and energy performance, findings from the questionnaire survey, data monitoring and computer simulation contended that with the passive design strategies minimum thermal comfort is attainable and energy savings predicted.

scholarly journals Transformation of an Office Building into a Nearly Zero Energy Building (nZEB): Implications for Thermal and Visual Comfort and Energy Performance

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 895 ◽  
Author(s):  
Ilaria Ballarini ◽  
Giovanna De Luca ◽  
Argun Paragamyan ◽  
Anna Pellegrino ◽  
Vincenzo Corrado
Keyword(s):  
Thermal Comfort ◽  
Energy Savings ◽  
Energy Performance ◽  
Primary Energy ◽  
Building Envelope ◽  
Office Building ◽  
Indoor Environmental Quality ◽  
Visual Comfort ◽  
Zero Energy ◽  
Efficiency Measures

Directive 2010/31/EU promotes the refurbishment of existing buildings to change them into nearly zero-energy buildings (nZEBs). Within this framework, it is of crucial importance to guarantee the best trade-off between energy performance and indoor environmental quality (IEQ). The implications of a global refurbishment scenario on thermal and visual comfort are assessed in this paper pertaining to an existing office building. The retrofit actions applied to achieve the nZEB target consist of a combination of envelope and technical building systems refurbishment measures, involving both HVAC and lighting. Energy and comfort calculations were carried out through dynamic simulation using Energy Plus and DIVA, for the thermal and visual performance assessments, respectively. The results point out that energy retrofit actions on the building envelope would lead to significant improvements in the thermal performance, regarding both energy savings (−37% of the annual primary energy for heating) and thermal comfort. However, a daylighting reduction would occur with a consequent higher electricity demand for lighting (36%). The research presents a detailed approach applicable to further analyses aimed at optimizing the energy efficiency measures in order to reduce the imbalance between visual and thermal comfort and to ensure the best performance in both domains.

scholarly journals Operation Testing of an Advanced Personalized Ventilation System

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1596 ◽  
Author(s):  
Csáky ◽  
Kalmár ◽  
Kalmár
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Distribution System ◽  
Noise Level ◽  
Background Noise ◽  
Ventilation System ◽  
Air Distribution ◽  
Personalized Ventilation

Using personalized ventilation systems in office buildings, important energy saving might be obtained, which may improve the indoor air quality and thermal comfort sensation of occupants at the same time. In this paper, the operation testing results of an advanced personalized ventilation system are presented. Eleven different air terminal devices were analyzed. Based on the obtained air velocities and turbulence intensities, one was chosen to perform thermal comfort experiments with subjects. It was shown that, in the case of elevated indoor temperatures, the thermal comfort sensation can be improved considerably. A series of measurements were carried out in order to determine the background noise level and the noise generated by the personalized ventilation system. It was shown that further developments of the air distribution system are needed.

IMPROVEMENT OF THERMAL COMFORT INSIDE A MOSQUE BUILDING

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Fawaz Ghaleb Noman ◽  
Nazri Kamsah ◽  
Haslinda Mohamed Kamar
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Side Wall ◽  
The West ◽  
Cfd Simulations ◽  
Interior Space ◽  
Flow Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

A combined natural ventilation and mechanical fans are commonly used to cool the interior space inside the mosques in Malaysia. This article presents a study on thermal comfort in the Al-Jawahir Mosque, located in Johor Bahru, Malaysia. The objective is to assess the thermal comfort inside the mosque under the present ventilation system by determining the Predicted Mean Vote (PMV) and the Predicted Percentage of Dissatisfied (PPD). These values were then compared to the limits stated in the ASHRAE Standard-55. It was found that the PMV varies from 1.68 to 2.26 while the PPD varies from 61% to 87%. These show that the condition inside the mosque is quite warm. Computational fluid dynamics (CFD) method was used to carry out flow simulations, to identify a suitable strategy to improve the thermal comfort inside the mosque. Results of CFD simulations show that installing four exhaust fans above the windows on the west-side wall of the mosque is the most effective strategy to improve the thermal comfort inside the mosque. Both the PMV and PPD values can potentially be reduced by more than 60%.

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