Abstract
Efficient cooling and heating solutions for nearly zero-energy solar dwellings are required to mitigate climate change and to make dwellings sustainable. The installed pipeline for a radiant heating system, which is only used for space heating when heating is necessary, can also be used to cool the room with only the enthalpic use of natural city water by releasing the natural city water through the embedded pipeline already installed for radiant heating. Natural city water used for radiant cooling can be used in necessary locations such as for toilets, washing cars, laundry facilities, and garden water, which corresponds to approximately 56% of the water we use at home. As a result, the embedded pipes that make up a radiant heating system can be converted to a passive intelligent radiant cooling system with minimal added installation and control systems. Thermal comfort and behavior analyses in an enclosure with a radiant cooling system are fulfilled through experimentation, mean radiant temperature simulation, and asymmetric radiation calculation. No uncomfortable asymmetric radiation is encountered during the cooling period, so the cooling spaces are well controlled within the comfortable cooling range. A passive intelligent radiant cooling system that uses just the enthalpy of natural city water can be an appropriate ecological solution to better develop zero-energy dwellings. No extra cooling energy and power are required to cool a space that uses just enthalpy and pressure from natural city water.