Development of building thermal environment emulator to evaluate the performance of the HVAC system operation

Abstract

A "performance gap" arises when the actual value of building energy consumption during the operational phase deviates from the value predicted using simulation during the design phase. One cause of this performance gap is that operation is not ideal, as assumed in the simulation, and the control of the heating, ventilating, and air conditioning (HVAC) system is not optimized. These problems occur because the operator has not been trained sufficiently and/or the building automation system is not working as intended by the developer. Both problems are fundamentally caused by the fact that the quality of building operation cannot be quantitatively evaluated by comparison with other buildings because a building is a heterogenous, single-item product. To address the performance gap problem, we developed a method for quantitatively evaluating building operation using a precise simulation based on a thermal environment emulator. The emulator software was developed using the BACnet protocol as an interface to the real world and includes an occupant behavior model to enable the assessment of operation in terms of thermal comfort as well as energy performance. In this paper, we report on the program and network structure of the proposed emulator. In addition, we show the concrete results of changing the operational control, and we assess changes in energy performance and comfort from the perspective of Pareto efficiency.

The first world championship in cybernetic building optimization

“…As already mentioned, the championship was hosted on the emulator system described in our previous report (Togashi and Miyata 2019). This system can evaluate how energy performance and thermal comfort change with respect to the default operational parameters using the energy reduction ratio (ERR) and the dissatisfied reduction ration (DRR) given in Equations 3and 4, respectively, in which E is the primary energy consumption, D is the dissatisfaction rate, the subscript r indicates default operation, and the subscript opt indicates optimized operation.…”

“…Later, IEA Annex 25 examined applications for fault detection (IEA 1999) and, more recently, Bushby et al (2001Bushby et al ( , 2010 developed a comprehensive emulator that combines air conditioning and fire simulations (Virtual Cybernetic Building Testbed: VCBT). The authors also developed an emulator system for evaluating the tuning ability of equipment, which can predict not only the energy consumption, but also the thermal sensing of office workers (Togashi and Miyata 2019).…”

Environmental Thermal Performance of Prefabricated Buildings Based on Building Wall Energy-Saving Technology

“…This paper chooses to study the most commonly used masonry structure [12]. Under normal circumstances, the thicker the walls, the smaller the heat loss; however, in order not to increase the thickness of the wall or occupy the effective space of the house, it's necessary to consider from the aspects of energy saving, thermal insulation, service life, and costs, and combine with the actual materials available in the area of Inner Mongolia to prepare a new-type composite thermal insulation block for the building walls [13][14][15]. As a coarse and fine aggregate, ceramsite has certain thermal insulation properties.…”

Thermal Environment Optimization and Energy Saving of Residential Buildings under the Demand of Low-Carbon Operation

“…Because carbon emissions account for 37%-39% of the global total emissions, the construction industry has become one of the national key emission reduction fields. As an important part of the construction industry, it is of great significance for residential buildings to carry out production and operation activities with the goal of controlling carbon emissions to achieve short-term emission reduction targets [1][2][3][4]. Improving the thermal environment quality of buildings under the demand of low-carbon operation is beneficial to residents' physical and mental health, and also puts forward higher requirements for the design of thermal environment optimization of residential buildings.…”