scholarly journals Preliminary symptoms assessment of typical faults related to the fans and humidifiers of HVAC systems based on experimental data collected during Italian summer and winter

2021 ◽  
Vol 897 (1) ◽  
pp. 012009
Author(s):  
A Rosato ◽  
F Guarino ◽  
M El Youssef ◽  
S Sibilio ◽  
L Maffei
Keyword(s):  
Air Temperature ◽  
Indoor Air ◽  
Air Conditioning ◽  
Hvac Systems ◽  
Fault Detection And Diagnosis ◽  
Hvac System ◽  
Air Handling Unit ◽  
Air Volume ◽  
Detection And Diagnosis ◽  
Main Operating

Abstract The symptoms associated to the occurrence of typical faults in a heating, ventilation and air-conditioning (HVAC) system, including a single duct dual fan constant air volume air-handling unit, have been experimentally characterized. The operation of the HVAC unit with 3 artificially forced faults ((1) reduced velocity of the supply air fan, (2) reduced velocity of the return air fan, (3) the valve supplying the humidifier kept always closed) has been analysed and compared with that of healthy operation of the same plant under very similar boundary conditions (outside air temperature and initial indoor air temperature) during Italian summer and winter in order to preliminarily assess (i) the effects on the main operating parameters, and (ii) generate preliminary operation data to assist further research in fault detection and diagnosis of HVAC systems.

scholarly journals ANALYSIS OF EQUIPMENT FAULTS IN INDOOR CLIMATE SYSTEMS AND THEIR DETECTION AND DIAGNOSIS MEASURES

2020 ◽  
Vol 12 (0) ◽  
pp. 1-7
Author(s):  
Violeta Misevičiūtė
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Hvac Systems ◽  
Fault Detection And Diagnosis ◽  
Indoor Climate ◽  
Equipment Failures ◽  
Climate Systems ◽  
Detection And Diagnosis ◽  
Proper Operation ◽  
Equipment Performance

Indoor climate systems required to provide indoor climate and ensure indoor air quality, failures affect the amount of energy consumed in a building, although insufficient attention is paid to their operation. The energy consumption can be reduced due to ensured proper operation of indoor climate systems avoiding equipment faults. The article reviews scientific articles, those represent typical heating, ventilation and air conditioning (HVAC) systems equipment faults of the most energy intensive office and commercial buildings. Measures of detecting and diagnosis equipment failures as well are identified. A generalized overview of the study area shows the typical faults of the indoor climate system are related to the control of the devices, sensors, deterioration of equipment performance. The most commonly used methods for detecting and diagnosing faults are automated fault detection and diagnosis (AFDD) methods. Possible solutions for troubleshooting HVAC systems are presented.

scholarly journals Fault Detection and Diagnosis of Air Handling Unit: A Review

2019 ◽  
Vol 255 ◽  
pp. 06001 ◽  
Author(s):  
Cheng Yew Leong
Keyword(s):  
Fault Detection ◽  
Air Conditioning ◽  
Early Stage ◽  
Fault Detection And Diagnosis ◽  
Commercial Building ◽  
Air Handling Unit ◽  
Operations And Maintenance ◽  
Detection And Diagnosis ◽  
Air Conditioning Systems ◽  
And Control

Air-conditioning systems consumed the most energy usage nearly 45% of the total energy used in commercial-building. Where AHU is one of the most extensively operated equipment and this device is typical customize and complex which can results in hardwire failure and controller errors. The efficiency of the system is very much depending on the proper functioning of sensors. Faults arising from the sensors and control systems are a major contribution to the energy wastage. As such faults often go unnoticed for extended periods of time until the deterioration in performance becomes great enough to trigger comfort complaints or total equipment failure. Energy could be reduced if those faults can be detected and identified at early stage. This paper aims to review of various existing automated fault detection and diagnosis (AFDD) methods for an Air Handling Unit. The background of AHU system, general fault detection and diagnosis framework and typical faults in AHU is described. Comparison and evaluation of the various methodologies will be reviewed in this paper. This comparative study also reveals the strengths and weaknesses of the different approaches. The important role of fault diagnosis in the broader context of air- conditioning is also outlined. By identifying and diagnosing faults to be repaired, these techniques can benefits building owners by reducing energy consumption, improving indoor air quality and operations and maintenance.

Nonlinear Control of an Air Handling Unit Using Feedback Linearization

2009 ◽  
Author(s):  
Hamed Moradi ◽  
Majid Saffar-Avval
Keyword(s):  
Air Conditioning ◽  
Feedback Linearization ◽  
Hvac Systems ◽  
Pi Controller ◽  
Hvac System ◽  
Flow Rates ◽  
Air Handling Unit ◽  
Transfer Rules ◽  
And Control ◽  
Dynamic Variables

Heating, ventilation and air conditioning (HVAC) systems are equipments used to maintain satisfactory comfort conditions in buildings. Also, energy consumption of ventilated buildings highly depend on the design, performance and control of HVAC systems. In this paper, nonlinear model of a multi-variable HVAC system is considered in which the control inputs are the air and cool water flow rates. Using thermodynamics and heat transfer rules, differential and consequently state space equations of the system are represented. To achieve a good performance, dynamic variables such as output temperature and relative humidity must be controlled. Using input-output feedback linearization, a PI controller is designed. It is shown that by applying the controller, system tracks from one operating point to another with an appropriate specification of time response. In addition, using feedback linearization guarantees robustness of the system against the parametric uncertainties associated with dynamic model.

scholarly journals Automatic and Noninvasive Indoor Air Quality Control in HVAC Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
M. C. Basile ◽  
V. Bruni ◽  
F. Buccolini ◽  
D. De Canditiis ◽  
S. Tagliaferri ◽  
...  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Air Conditioning ◽  
Ventilation System ◽  
Hvac Systems ◽  
Hvac System ◽  
Noninvasive Method ◽  
Time Table ◽  
Air Quality Control

This paper presents a methodology for assessing and monitoring the cleaning state of a heating, ventilation, and air conditioning (HVAC) system of a building. It consists of a noninvasive method for measuring the amount of dust in the whole ventilation system, that is, the set of filters and air ducts. Specifically, it defines the minimum amount of measurements, their time table, locations, and acquisition conditions. The proposed method promotes early intervention on the system and it guarantees high indoor air quality and proper HVAC working conditions. The effectiveness of the method is proved by some experimental results on different study cases.

scholarly journals An Autonomic Cycle of Data Analysis Tasks for the Supervision of HVAC Systems of Smart Building

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3103
Author(s):  
Jose Aguilar ◽  
Douglas Ardila ◽  
Andrés Avendaño ◽  
Felipe Macias ◽  
Camila White ◽  
...  
Keyword(s):  
Data Analysis ◽  
Fault Detection ◽  
Hvac Systems ◽  
Economic Benefits ◽  
Fault Detection And Diagnosis ◽  
Hvac System ◽  
Smart Buildings ◽  
Detection And Diagnosis ◽  
Early Fault Detection

Early fault detection and diagnosis in heating, ventilation and air conditioning (HVAC) systems may reduce the damage of equipment, improving the reliability and safety of smart buildings, generating social and economic benefits. Data models for fault detection and diagnosis are increasingly used for extracting knowledge in the supervisory tasks. This article proposes an autonomic cycle of data analysis tasks (ACODAT) for the supervision of the building’s HVAC systems. Data analysis tasks incorporate data mining models for extracting knowledge from the system monitoring, analyzing abnormal situations and automatically identifying and taking corrective actions. This article shows a case study of a real building’s HVAC system, for the supervision with our ACODAT, where the HVAC subsystems have been installed over the years, providing a good example of a heterogeneous facility. The proposed supervisory functionality of the HVAC system is capable of detecting deviations, such as faults or gradual increment of energy consumption in similar working conditions. The case study shows this capability of the supervisory autonomic cycle, usually a key objective for smart buildings.

scholarly journals A Multi-Timescale Bilinear Model for Optimization and Control of HVAC Systems with Consistency

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 400 ◽  
Author(s):  
Zelin Nie ◽  
Feng Gao ◽  
Chao-Bo Yan
Keyword(s):  
Optimization Model ◽  
Air Conditioning ◽  
State Of The Art ◽  
Hvac Systems ◽  
Practical Significance ◽  
Hvac System ◽  
Bilinear Model ◽  
Optimization And Control ◽  
And Control ◽  
Slow Timescale

Reducing the energy consumption of the heating, ventilation, and air conditioning (HVAC) systems while ensuring users’ comfort is of both academic and practical significance. However, the-state-of-the-art of the optimization model of the HVAC system is that either the thermal dynamic model is simplified as a linear model, or the optimization model of the HVAC system is single-timescale, which leads to heavy computation burden. To balance the practicality and the overhead of computation, in this paper, a multi-timescale bilinear model of HVAC systems is proposed. To guarantee the consistency of models in different timescales, the fast timescale model is built first with a bilinear form, and then the slow timescale model is induced from the fast one, specifically, with a bilinear-like form. After a simplified replacement made for the bilinear-like part, this problem can be solved by a convexification method. Extensive numerical experiments have been conducted to validate the effectiveness of this model.

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