Simulation Model of Automated HVAC System Control Strategy With Thermal Comfort and Occupancy Considerations

2017 ◽  
Author(s):  
Bo Peng ◽  
Sheng-Jen Hsieh
Keyword(s):  
Thermal Comfort ◽  
Simulation Model ◽  
Control Strategy ◽  
Energy Performance ◽  
System Control ◽  
Hvac System ◽  
Building Automation ◽  
Simulation Tools ◽  
Automation Systems ◽  
Different Seasons

Currently, design and control of HVAC system in buildings rely heavily on simulation tools. However, the common tools available often fail to optimize occupants’ comfort directly, nor do they consider real-time variations in occupancy that affect comfort and energy performance. To address these limits, this research designed an occupancy-based and thermal comfort-driven building automation simulation model. A single-space prototype lab room was co-simulated using EnergyPlus and MATLAB with the help of BCVTB and MLE+ as middleware. Various climate scenarios from four cities in the U.S. in different seasons were examined. Results suggest that overall, compared to a conventional temperature-driven control strategy baseline, the proposed system can minimize thermal comfort violation (in term of PMV model, |PMV|>0.5 is considered as a violation) to 7% and reduce occupants’ thermal discomfort by 62.5% on average. Meanwhile, energy consumption remains same or reduced (up to 2% reduction). Due to its simplicity, this strategy is relatively easy to implement in real-world building automation systems with appropriate sensor placement in modern buildings.

scholarly journals The Derivation of Cooling Set-Point Temperature in an HVAC System, Considering Mean Radiant Temperature

2019 ◽  
Vol 11 (19) ◽  
pp. 5417
Author(s):  
Jinmog Han ◽  
Jongkyun Bae ◽  
Jihoon Jang ◽  
Jumi Baek ◽  
Seung-Bok Leigh
Keyword(s):  
Thermal Comfort ◽  
Indoor Environment ◽  
Thermal Characteristics ◽  
Weather Conditions ◽  
System Control ◽  
Hvac System ◽  
Mean Radiant Temperature ◽  
Point Temperature ◽  
Set Point ◽  
Radiant Temperature

Heating, ventilation, and air-conditioning (HVAC) systems usually have a set-point temperature control feature that uses the indoor dry-bulb temperature to control the indoor environment. However, an incorrect set-point temperature can reduce thermal comfort and result in unnecessary energy consumption. This study focuses on a derivation method for the optimal cooling set-point temperature of an HVAC system used in office buildings, considering the thermal characteristics and daily changes in the weather conditions, to establish a comfortable indoor environment and minimize unnecessary energy consumption. The operative temperature is used in the HVAC system control, and the mean radiant temperature is predicted with 94% accuracy through a multiple regression analysis by applying the indoor thermal environment data and weather information. The regression equation was utilized to create an additional equation to calculate the optimal set-point temperature. The simulation results indicate that the HVAC system control with the new set-point temperatures calculated from the derived equation improves thermal comfort by 38.5% (26%p). This study confirmed that a cooling set-point temperature that considers both the thermal characteristics of a building and weather conditions is effective in enhancing the indoor thermal comfort during summer.

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.

scholarly journals An Evaluation of the Ceiling Depth’s Impact on Skylight Energy Performance Predictions Through a Building Simulation

2020 ◽  
Vol 12 (8) ◽  
pp. 3117
Author(s):  
Amina Irakoze ◽  
Young-A Lee ◽  
Kee Han Kim
Keyword(s):  
Simulation Model ◽  
Energy Efficient ◽  
Simulation Modeling ◽  
Critical Factor ◽  
Building Energy ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Simulation Tools ◽  
Performance Predictions ◽  
The Impact

This study evaluated the impact of including a building ceiling depth into a simulation model on skylight efficiency under two climatic conditions (Ulsan and Seoul, South Korea). Using Radiance and EnergyPlus simulation tools integrated in OpenStudio program by National Renewable Energy Laboratory, Golden, Colorado, USA, daylighting and building energy consumption were computed and assessed to evaluate the energy performance and optimization of skylights. Skylight-to-roof ratios from 1% to 25% were analyzed with ceiling depths of 1.5 m to 3 m. The results showed that the range for efficient skylight ratios became smaller with an increase of ceiling depth; in addition, small apertures were more affected by the ceiling depth than were large apertures. Under Ulsan’s climatic conditions, the optimal skylight-to-roof ratios were 8%, 9%, 10%, and 11% for ceiling depths of 1.5 m, 2 m, 2.5 m, and 3 m, respectively. In Seoul, 8% and 9% were the optimum skylight-to-roof ratios for ceiling depths of 1.5 m and 2 m, respectively; no skylight was energy efficient for a ceiling deeper than 2 m. This study indicates that ceiling depth is a critical factor in the evaluation of skylight performance; thus, it should not be excluded from a simulation model, as is often done to simplify simulation modeling.

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 Building Energy Management for Passive Cooling Based on Stochastic Occupants Behavior Evaluation

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 138
Author(s):  
Michele Roccotelli ◽  
Alessandro Rinaldi ◽  
Maria Pia Fanti ◽  
Francesco Iannone
Keyword(s):  
Thermal Comfort ◽  
Energy Management ◽  
Natural Ventilation ◽  
Building Energy ◽  
Energy Performance ◽  
Passive Cooling ◽  
Deterministic Models ◽  
Building Energy Management ◽  
Solar Shading ◽  
Automation Systems

The common approach to model occupants behaviors in buildings is deterministic and consists of assumptions based on predefined fixed schedules or rules. In contrast with the deterministic models, stochastic and agent based (AB) models are the most powerful and suitable methods for modeling complex systems as the human behavior. In this paper, a co-simulation architecture is proposed with the aim of modeling the occupant behavior in buildings by a stochastic-AB approach and implementing an intelligent Building Energy Management System (BEMS). In particular, optimized control logics are designed for smart passive cooling by controlling natural ventilation and solar shading systems to guarantee the thermal comfort conditions and maintain energy performance. Moreover, the effects of occupant actions on indoor thermal comfort are also taken into account. This study shows how the integration of automation systems and passive techniques increases the potentialities of passive cooling in buildings, integrating or replacing the conventional efficiency strategies.

scholarly journals HVAC Energy Savings and IEQ for Occupancy-Based Control by Side-by-Side Experimental Study

2021 ◽  
Author(s):  
Meng Kong ◽  
Bing Dong ◽  
Rongpeng Zhang ◽  
Zheng O’Neill
Keyword(s):  
Thermal Comfort ◽  
Energy Saving ◽  
Control Method ◽  
Outdoor Environment ◽  
Detection Accuracy ◽  
System Control ◽  
Building Energy Efficiency ◽  
Occupant Behavior ◽  
Hvac System ◽  
Building System

Building sensing technologies have evolved rapidly in the last two decades in aid of monitoring building environment and energy system performance. A series of occupancy sensing systems were developed to track the occupant behavior in the indoor space. Occupancy-based building system control is defined as a control method that adjusts the building system operation schedules and setpoints based on the measured occupant behavior and has been identified as a smart building control strategy that can improve building energy efficiency as well as occupant comfort. Some studies demonstrated energy-saving potential and comfort-maintaining capability from occupancy-based control (OBC). This study adopted a first-of-its-kind side-by-side experimental approach to quantify the performance of the occupancy-based Heating, Ventilation, and Air-Conditioning (HVAC) system control in commercial buildings. Three state-of-the-art occupancy sensing technologies were integrated into the real-time HVAC system control in this study. <a>Their detection accuracy and its effectiveness on energy-saving and thermal comfort were analyzed. It was found that the OBC can maintain good thermal comfort and perceived indoor air quality with a satisfaction ratio greater than 80%. Although the daily energy-saving by OBC varied with occupancy sensor accuracy and outdoor environment conditions, the weekly averaged HVAC energy saving was between 17-24%.</a>

scholarly journals HVAC Energy Savings and IEQ for Occupancy-Based Control by Side-by-Side Experimental Study

2021 ◽  
Author(s):  
Meng Kong ◽  
Bing Dong ◽  
Rongpeng Zhang ◽  
Zheng O’Neill
Keyword(s):  
Thermal Comfort ◽  
Energy Saving ◽  
Control Method ◽  
Outdoor Environment ◽  
Detection Accuracy ◽  
System Control ◽  
Building Energy Efficiency ◽  
Occupant Behavior ◽  
Hvac System ◽  
Building System

Building sensing technologies have evolved rapidly in the last two decades in aid of monitoring building environment and energy system performance. A series of occupancy sensing systems were developed to track the occupant behavior in the indoor space. Occupancy-based building system control is defined as a control method that adjusts the building system operation schedules and setpoints based on the measured occupant behavior and has been identified as a smart building control strategy that can improve building energy efficiency as well as occupant comfort. Some studies demonstrated energy-saving potential and comfort-maintaining capability from occupancy-based control (OBC). This study adopted a first-of-its-kind side-by-side experimental approach to quantify the performance of the occupancy-based Heating, Ventilation, and Air-Conditioning (HVAC) system control in commercial buildings. Three state-of-the-art occupancy sensing technologies were integrated into the real-time HVAC system control in this study. <a>Their detection accuracy and its effectiveness on energy-saving and thermal comfort were analyzed. It was found that the OBC can maintain good thermal comfort and perceived indoor air quality with a satisfaction ratio greater than 80%. Although the daily energy-saving by OBC varied with occupancy sensor accuracy and outdoor environment conditions, the weekly averaged HVAC energy saving was between 17-24%.</a>

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