A Study on the Control Method Without Stratification of Single Duct VAV Terminal Units

Kim, Hyo-Jun; Kang, Su-Hyun; Cho, Young-Hum

doi:10.3130/jaabe.14.467

Cited by 10 publications

(5 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The typical VAV terminal unit is composed of an air flow sensor, a damper, and a reheating coil [1,10]. In order to control the air flow supplied to each room, the air flow rate is checked through the air flow sensor installed at the inlet of the terminal unit, and the air flow rate is controlled by adjusting the damper opening ratio.…”

Section: Vav Terminal Unit and Volume Dampermentioning

confidence: 99%

“…The data of the fan speed, damper opening ratio, and damper differential pressure were collected through the BAS, and the supply air flow rate was measured using a hot-wire anemometer. Figure 3 and Equation (10) were used to apply the virtual air flow rate measurement procedure and calculate the air flow rate. The uncertainty of the calculated air flow rate was verified using Equations (11) and (12).…”

Section: Verification Of Vav Virtual Air Flow Sensormentioning

confidence: 99%

See 1 more Smart Citation

Development of Virtual Air Flow Sensor Using In-Situ Damper Performance Curve in VAV Terminal Unit

Kim

Cho

2019

Energies

Self Cite

View full text Add to dashboard Cite

In this study, we developed a virtual air flow sensor using an in-situ damper performance curve to secure the stability of control of the variable air volume (VAV) terminal unit, and also established the in-situ measurement procedure. The minimum air flow rate of the VAV terminal unit was related to the energy consumption, it was important to determine the minimum air flow rate suitable for the situation of each room in terms of energy saving. However, it was difficult to set the minimum air flow rate low setpoint due to the low accuracy of the air flow sensor of the VAV terminal unit. This paper suggested a virtual air flow sensing method using an in-situ damper performance curve in the VAV terminal unit. The input factors of the virtual sensor were developed on the basis of the supply fan speed and damper opening ratio, which could be easily obtained from the existing control system. In addition, the in-situ measurement procedure of the virtual air flow sensor was developed by dividing the procedure into five steps. Finally, reliability of the virtual air flow sensor was evaluated through uncertainty analysis of input variables and relative error analysis, in comparison with the conventional air flow rate measurement method. The developed virtual air flow sensor was found to have an uncertainty of up to 8.8%, and it was also found that the closer to the maximum the values of the input variables, the lower the uncertainty. In addition, verification of relative error with respect to the measured values by the hot-wire anemometer was conducted by varying operation conditions to a total of 12 cases, and as a result, relative error was found to be up to 5.6%. In addition, the results of long-term experiment showed that relative error was within about 9.5%, and thus, the feasibility for field application and control was confirmed.

show abstract

Section: Vav Terminal Unit and Volume Dampermentioning

confidence: 99%

Section: Verification Of Vav Virtual Air Flow Sensormentioning

confidence: 99%

Development of Virtual Air Flow Sensor Using In-Situ Damper Performance Curve in VAV Terminal Unit

Kim

Cho

2019

Energies

Self Cite

View full text Add to dashboard Cite

show abstract

“…The air flow rate of variable air volume (VAV) terminal unit adjust the supply air flow rate and temperature based on the indoor load, ventilation requirement, and stratification [1][2][3]. Accurate measurement of air flow rate is essential in automatic building control using the VAV system.…”

Section: Introductionmentioning

confidence: 99%

Development of Air Flow Rate Prediction Model Using Multiple Regression in VAV Terminal Unit

Kim

Shin

et al. 2020

Energies

Self Cite

View full text Add to dashboard Cite

Accurate measurement of air flow rate is essential in automatic building control using the variable air volume (VAV) system. In order to solve the problems of the existing air flow measurement method and improve the accuracy of air flow control, this study developed a data-based multiple regression air flow prediction model. The independent variables used in the development of the predictive model were selected as the factors used for control and monitoring when operating with variable air flow rate in the existing air conditioning system. Data collection and correlation between independent variables and air flow rate of the terminal unit were analyzed. Using the IBM SPSS statistics version 25, an air flow rate prediction model was developed using multiple regression analysis. Reliability of model was evaluated by comparing the measured airflow. The relative error of −9.3% to 10.4% is shown when comparing the estimated air flow rate by the developed model with the measured air flow rate.

show abstract

“…Kang et al [11] determined the relationship between supply temperature, air flow rate and energy by height and presented a terminal unit air flow rate control method considering stratification and IAQ. Kim et al [12] presented a method for controlling the supply temperature and air flow rate of a terminal unit to control stratification. Taylor et al [13] conduct an energy study on systems that use the conventional box and dual maximum box control methods.…”

Section: Introductionmentioning

confidence: 99%

Development and Evaluation of Applicable Optimal Terminal Box Control Algorithms for Energy Management Control Systems

Seong¹,

Cho

2016

Sustainability

Self Cite

View full text Add to dashboard Cite

Abstract:Common energy management control systems (EMCS) in building HVAC systems could be made much more energy efficient without sacrificing comfort. Most researchers have focused on implementing optimal control algorithms in Variable Air Volume (VAV) systems with EMC functions. Previous studies have paid little attention to using terminal box EMC functions integrated with main AHU (Air Handling Unit) systems. Terminal boxes with EMCS may cause occupant discomfort and waste excessive energy if they do not have the proper operation control functions. The objective of this study is to evaluate the impact of energy consumption and estimate building energy savings on the optimal minimum air flow of single duct VAV terminal boxes and develop applicable optimal terminal box control algorithms for EMCS. This paper presents a dynamic model of a VAV terminal box with hydronic reheat, develops optimal terminal box control algorithms and applies the developed EMCS algorithms to an actual building. The results of this study show that optimal terminal box control algorithms can stably maintain the set room air temperature and reduce energy consumption for varying heating loads compared to conventional control algorithms.

show abstract

A Study on the Control Method Without Stratification of Single Duct VAV Terminal Units

Cited by 10 publications

References 10 publications

Development of Virtual Air Flow Sensor Using In-Situ Damper Performance Curve in VAV Terminal Unit

Development of Virtual Air Flow Sensor Using In-Situ Damper Performance Curve in VAV Terminal Unit

Development of Air Flow Rate Prediction Model Using Multiple Regression in VAV Terminal Unit

Development and Evaluation of Applicable Optimal Terminal Box Control Algorithms for Energy Management Control Systems

Contact Info

Product

Resources

About