A 1-pipe water distribution system has several advantages, including simplicity, lower installation costs, and reduced space requirements. Since there is only one main pipe, it requires less material and labor to install, making it a cost-effective option. Additionally, the single pipe layout makes it easier to maintain and repair compared to more complex systems. However, 1-pipe systems are limited in their ability to provide simultaneous heating and cooling, which can be a significant drawback in many applications.