## 3 A Summary of the Research on Integrated Building and Energy Systems
As per the study of [PERSON] [12], 2017, \"To reduce the heating energy consumption, air source heat pumps are proposed in this study to produce low-temperature hot water for the building envelope. A comprehensive numerical model is adopted to simulate the dynamic heat transfer in the duct-embedded structure, and the model has been verified by experiment. The proposed system is more suitable for cold areas because more heat transfer can be reduced there. The water temperature significantly affects the system performance and room temperature water is recommended. Overall, the proposed system is efficient as an auxiliary heating system\". As per the study of [PERSON], [PERSON] [13], 2019, \"This study proposes simple operator-level guidelines to enhance the practical use of TABS by considering the risk of condensation in hot and humid environments. Therefore, the weather conditions and characteristics of the TABS system were analyzed and possible simple solutions to avoid condensation were proposed. To apply both strategies, cooling operation guidelines were proposed with a simple calculation of the internal dew point temperature, which could prevent condensation at any time\". As per the study of [PERSON]. [PERSON] [14], 2020, \"A thermally activated phase change composite wall (TAPCW) concept is proposed to address the retrofitting issues faced by existing buildings, that is, to replace the interlayer embedded in the duct with an encapsulated PCM panel and relocate it to the exterior of the supporting layer. This work focuses on investigating the thermal and energy savings of TAPCW in the winter climate of northern China through a validated numerical model\". As per the study of [PERSON], [PERSON], and [PERSON] [15], 2021, \"The study describes ITAP panels--as indoor thermally active panels with an integrated active surface in an innovative way that combines existing building and energy systems into one compact unit, thus creating combined building-energy systems. These are building structures with an internal energy source. The main benefit of ITAP panels is the possibility of unified and prefabricated production. At the same time, they represent a reduction of production costs due to their technological production process, a reduction of assembly costs due to a reduction of steps during implementation on the construction site, and a reduction of implementation time due to their application method\". As per the study of [PERSON], [PERSON], [PERSON], and [PERSON] [16], 2021, \"The paper presents that energy systems built into one of the building structures that serve to capture solar energy, geothermic energy, and ambient energy or that have the function of the end elements of the heating, cooling, and ventilation system are generally called combined building-energy systems. The paper presents a cross-section of our team's research and scientific activities in the field of combined building-energy systems\". As per the study of [PERSON], [PERSON], and [PERSON] [17], 2021, \"The study compares a classic perimeter cladding equipped with thermal insulation meeting the normative requirements for thermal resistance and a perimeter cladding with an integrated thermal barrier significantly eliminating the thickness of thermal insulation. We evaluate the use of the thermal barrier using: economic indicator one, where we compare the cost of heat delivered to the TB in a structure with significantly eliminated thermal insulation and the saved cost of thermal insulation at the standard thickness; economic indicator two, where we compare the cost of heat delivered to the TB in a structure with significantly eliminated thermal insulation with the potential gain from the sale of the useful area of the building gained compared to the area at the normative thickness of thermal insulation; and economic indicator three, where we compare the cost of heat delivered to the TB in a structure with significantly eliminated thermal insulation with the cost of grey energy at the normative thickness of thermal insulation.