# Design and Analysis of a Floor Radiant Heating System Based on Energy Substitution Technology
## 6 Actual System Energy Savings Calculation and Analysis
### Operation and Analysis  
The calculation procedure of the heat energy provided by the proposed floor radiant heating system refers to Equations (3)-(18). To evaluate the energy saving potential of the proposed floor radiant heating system accurately, a modified equation for the proposed floor radiant heating system is shown by Equation (14). To calculate the available heat energy of the proposed floor radiant heating system under extreme conditions, the revised calculation method is also given by Equations (16)-(18). All the calculation methods have been used for the actual heating system, and the analysis will be shown in the subsequent paragraphs.  
A series of tests and data collection for one year's operation of a civil building have been implemented, and the energy saving of the proposed floor radiant heating system has been calculated and analyzed in this paper.  
The heating area of the civil building is approximately 1500 m\({}^{2}\). The heating period for this region is from 15 November to 15 March of the following year.  
As the proposed floor radiant heating system is a solar floor radiant heating system, the heating time of the system is determined according to the indoor temperature setting (20 \({}^{\circ}\)C). The heating system starts to run when the indoor temperature is below the set temperature. The total running time of the proposed floor radiant heating system is 10,551,600 s based on one year's test and data collection. The operation time of the proposed floor radiant heating system is 241,200 s when the indoor temperature is below the set temperature in the transition season, and its operation time is 486,000 s under extreme conditions. The ratio of the transition season and extreme conditions to the running time is 2.3% and 4.6%, respectively. Therefore, it can be seen that the proposed floor radiant heating system has heating flexibility, which means that it can meet the heating requirements throughout the year.  
Based on the calculation from Equations (3)-(18), the average energy per unit area provided by the proposed floor radiant heating system is 43.26 W/m\({}^{2}\), excluding extreme conditions. This confirms the energy saving potential relative to the traditional floor radiant heating system. Compared with the conventional radiant heating system powered by fossil fuels, standard coal consumption and CO\({}_{2}\) emissions can be reduced by 17.3 kg/m\({}^{2}\) and 43.1 kg/m\({}^{2}\), respectively, in this proposed floor radiant heating system on the basis of the energy saving potential. From an economic point of view, the heating price of this civil building can be reduced by more than 6 yuan/m\({}^{2}\).  
The proposed calculation method involves the total heat calculation method, the revised calculation method and total heat calculation method under extreme conditions, which can be provided by the proposed floor radiant heating system. The calculation and analysis of the solar floor radiant heating system can be achieved by this calculation method under different conditions. The proposed floor radiant heating system has heating flexibility and can meet the heating requirements for the transition season and achieve energy savings and emission reductions. In the case of no heating, the excess energy of the proposed floor radiant heating system can be stored or used for basic household energy.