# Design and Analysis of a Floor Radiant Heating System Based on Energy Substitution Technology
## 1 Introduction  
Floor radiant heating systems have become increasingly popular. These systems have the advantages of being comfortable and healthy, and they have a long-life span and energy savings compared with traditional heating systems. A comparison and analysis of the performance of different low-temperature radiant heating systems on walls, ceilings and floors were conducted by [PERSON] et al. They found that floor heating is the best method, with low energy consumption and operating costs [1]. However, a traditional floor heating system generally relies on the burning of fossil fuels. First, serious haze has been caused by traditional systems. Second, the system produces hot water at higher temperatures, which affects the comfort level, wastes energy and shortens the life span of the hot water pipes. Solar energy is a clean renewable energy that has received increasing attention. Many countries regard the development of solar energy utilization technologies as important for sustainable development and consider that a floor radiant heating system driven by solar energy is the best form of heating. However, the existing floor radiant heating system driven by solar energy requires additional heating due to the insufficient stability of solar energy, which is readily affected by season, location, climate and other factors. Many scholars have regarded photovoltaic and photothermalfloor radiant heating system technology as a research hot spot and have applied it to heating systems. [PERSON] et al. conducted a series of trials on the heating capacity of photovoltaic heat pumps. Photovoltaic systems generate electricity and store it in the battery. The inverter supplies electricity to the pump. The system supplies hot water to the floor radiant system [2; 3]. A combination system with a photovoltaic and thermal system and a ground source heat pump was discussed and evaluated by [PERSON] et al. [4]. The average seasonal performance of the combination system improved by almost 55.3% compared with the conventional system. The application of a ground source heat pump system coupled with a radiator and radiant floor heating systems was put forward by [PERSON] et al. [5]. These authors discussed the coefficient of performance and CO\({}_{2}\) emissions of different heating systems in terms of thermal comfort, energy consumption and environmental impact. [PERSON] and [PERSON] [6] also conducted a series experiments to test the performance of the ground-coupled heat pump system in different operating modes. The main performance energy efficiency and CO\({}_{2}\) emissions were tested and analyzed to show the advantage of the operational system. [PERSON] et al. [7] studied the performance of photovoltaic-thermal (PVT) hybrid collectors as part of a solar thermal system. The application of efficient PVT collectors is preferable to conventional PV and solar thermal components from a potential energy savings aspect. A model was developed by [PERSON] et al. [8] to evaluate the performance of hybrid PVT systems for the provision of electricity and hot water. It was demonstrated that the configuration of the PVT system enhanced its thermal and electrical characteristics observably. The combination of a photovoltaic and photothermal system was proposed by the authors in an earlier study. Solar power was used to supply power to the system or an external device, and solar heat was used to generate heat. Consequently, the energy-saving effect and economic efficiency of the solar system improved [9]. The control strategy of a heating system has also been the focus of extensive research. An accurate mathematical model is required to set parameters in the traditional PID (Proportion, Integration, Differentiation) temperature controller in which the coefficient of proportion, integration and differentiation \(K_{p}\), \(K_{i}\), \(K_{d}\) are generally fixed.