In this study

a building in Shanghai is taken as the study object and the existing floor radiant cooling system of the building is simulated using Trnsys. Then

according to the actual condition of the building

a roof radiant cooling system is designed for the building which is compared to the floor radiant cooling system. The results show that the roof radiant cooling system can more rapidly adjust the indoor environment and has a smaller thermal inertia than that of the floor radiant cooling system. During the entire cooling season

the energy consumption of the floor radiant cooling system is 35 826.2 kW?h and that of the roof radiant cooling system is 34 181.9 kW?h

which is 4.59% lower. Given the continuous operation of the air-conditioning system in the building

a running schedule for the roof radiant cooling system is designed that can reduce the energy consumption of the system on the premise of meeting the indoor thermal environment standard. On this basis

given the long-term constant operating conditions of the air-conditioning system in the building

a variable water flow rate control system and variable water temperature control system are designed

respectively

and the actual operation effects of the two control systems are compared. The results show that the variable water temperature system more quickly responds to the changes in indoor thermal environment and consumes less energy. After improving the system running schedule and adopting variable water temperature control

the total energy consumption of the roof radiant cooling system during the cooling season was 14 665.3 kW?h

much lower than the energy consumption of the original system.