project management issues.
[7]
Many buildings fail to achieve their designed efficiency because of the absence
of a structured delivery framework that connects design, installation, and performance verification. Therefore,
a structured HVAC framework that integrates technical design, interdisciplinary coordination, commissioning
procedures, and performance benchmarking is needed to reduce energy waste, improve indoor comfort, and
ensure that actual system performance matches the original design intent.
[9,10]
While HVAC energy efficiency
and performance monitoring have been thoroughly investigated, most research focuses on individual
technologies, intelligent control strategies, or simulation models rather than structured project delivery
frameworks.
[4, 7,11]
Previous studies highlight the importance of system optimization and energy modeling;
however, they often do not integrate design verification, commissioning procedures, and operational
performance monitoring within a unified process.
[9,10]
Recent research further highlights that the building
energy-performance gap can result from interactions across the building lifecycle rather than from a single
technical cause.
[12]
As a result, a gap exists between the predicted HVAC performance during design and actual
building operation.
[7,12]
To address this gap, this study proposes a stage-gated HVAC performance assurance
framework that integrates technical verification, structured decision checkpoints, and lifecycle performance
monitoring to improve system reliability and energy efficiency.
2. Literature review
2.1 Intelligent control and automation
Recent literature highlights that advanced control methods using artificial intelligence (AI) and machine
learning (ML) can improve HVAC system efficiency and flexibility. Abida and Richter studied different neural
network models, such as CNN, LSTM, RNN-GRU, and attention-based methods for HVAC control
optimization.
[13]
Their review explained that these models can learn from historical building data and improve
temperature control and energy performance. However, they also state that these models must be tested on
different building types before large-scale implementation.
[4,13]
Ali and Aldaiyat developed an intelligent HVAC
control system based on support vector machine (SVM) algorithms for smart buildings.
[11]
Their system can
quickly adjust operating conditions to maintain indoor comfort. However, they reported that system accuracy
depends on good-quality data and fast response times.
[11]
Building automation systems (BASs) also plays an
important role in intelligent HVAC control. Advanced building operating system architectures have also been
proposed to integrate HVAC data streams, sensor networks, and control logic for improved system-level
optimization.
[14]
Mistry explained that automation systems monitor indoor air quality, temperature, and
humidity in real time and help improve system efficiency.
[3]
High-performance control sequences are also
recommended for reliable HVAC operation.
[9]
Grassi et al. reviewed more than 180 related studies and
concluded that HVAC control systems must balance energy savings with occupant comfort.
[15]
The authors
emphasized that user-friendly interfaces are necessary so that occupants can interact properly with the
system. From these studies, it is clear that intelligent HVAC systems can improve performance, but they
require proper commissioning, verified baseline data, and systematic validation procedures to operate
effectively.
[2,11]
2.2 Passive design and ventilation strategies
The literature highlights the importance of ventilation and passive design in reducing energy use and
improving occupant health. The British Standards Institution provides guidelines for natural ventilation
design in buildings.
[16]
These guidelines explain how building layout, window design, and airflow paths
influence ventilation effectiveness. Orme reported that nearly 48% of heating energy loss in buildings occurs
because of air change processes such as infiltration and ventilation.
[5]
This finding shows that uncontrolled air
leakage can significantly increase energy consumption. Mostafaeipour et al. studied wind catcher systems and
reported that they can reduce energy use and lower carbon emissions.
[17]
Yang validated computational fluid
dynamics (CFD) models for cross-ventilation analysis in naturally ventilated buildings.
[18]
Evola and Popov
compared turbulence models and reported that the RNG k-ε model predicts ventilation airflow more
accurately than the standard k-ε model does.
[19]
Mendell et al. reported that compared with naturally
ventilated buildings, mechanically ventilated office buildings presented greater irritation symptoms.
[2]
This
finding indicates that ventilation design affects occupant health and comfort. Siew et al. classified passive
design strategies for office buildings and reported that the proper use of natural ventilation and shading can
reduce energy consumption.
[20]
These studies confirm that proper building data collection, climate analysis,
and airflow modeling are essential in the early stage of HVAC planning.
[5,16,18]
2.3 Integrated energy systems and benchmarking
Modern HVAC systems often include energy recovery devices and environmentally friendly refrigerants. These
systems require proper modeling and performance verification. Cavique applied axiomatic design principles
and explained that adding energy recovery systems often requires complete system redesign rather than
simple modification.
[10]
Cortella et al. modeled integrated HVAC and refrigeration systems in supermarkets