UCL Institute for Environmental Design and Engineering


José R. Castaños

Distributed HVAC System Integration Through Ontology-based Translators

Funded by Consejo Nacional de Ciencia y Tecnología (CONACyT), México

Information from different domains coexist and communicate in smart buildings. Despite higher integration, energy consumption from Building Energy Systems (BES) continues to rise. Heating, Ventilation and Air Conditioning (HVAC) is acknowledged as the more energy-intensive BES. Through Building Energy Models (BEM) the physical characteristics and interactions within a building, are captured in mathematical abstractions. Simulation and optimisation of BEMs serve as a basis for decision making on HVAC system specification, components selection and layout dimensioning. Nonetheless, BEMs are generated at the final stages of design due to lack of interoperability with Building Information Models (BIM). Furthermore, input/output causality of BEMs fails to address the non-linear physical (BEM) and operational (BAS) interactions of distributed HVAC. As a result, information lag among these AEC models diminish Building Performance Simulation (BPS) scope. Moreover, BEMs causality hinders mechanical engineer’s capacity to design, optimise and control HVAC systems and their components. Therefore, it's important to address the efficient exchange of information allocated in AEC models to exploit the cyber-physical nature of intelligent HVAC. 

To overcome these barriers, environments that facilitate the integration of decentralised models in support of design, optimisation and control of BES, will emerge. Such perspective undertakes Model-based System Engineering (MBSE) principles that allow, 1) acausal and concurrent modelling, 2) hierarchical system representations and 3) models escalation. With MBSE, as a system model, complexity increases and reaches component level, boundary conditions among the system and its detailed components, need to be established to enable the verification and validation of the intended designs. This system-component data exchange can be addressed through tailored AEC domain ontologies. An ontology can be described as an information model that represents knowledge as a set of concepts within a specific domain and the relationship between them. Thus, through an ontology-based approach, an intelligent agent (IA) can reason information from a knowledge-graph to translate the require data among AEC models; allowing semantic interoperability. 

Technological advancements in Equation-based Object-oriented (EOO) modelling and Semantic-Web Technologies (SWT) present opportunities to standardise how a system and its detailed components are represented as both: 1) a data-model and 2) a mathematical model. Therefore, this research study aims to investigate the development of ontology-based translators that enable semantic interoperability among AEC models and consequently facilitate the representation of distributed HVAC systems and their components.