Why should a radon vent pipe be designed to slope back to the suction point?

The design of a radon vent pipe to slope back toward the suction point is crucial primarily to prevent moisture accumulation within the system. When moisture collects in a vent pipe, it can lead to several issues, such as an increase in pressure within the system, which might affect the radon mitigation effectiveness and possibly allow radon gas to re-enter the home. By ensuring that the pipe slopes back toward the suction point, any moisture that does enter the system can drain away, maintaining the efficiency of the system and reducing the risk of water-related problems that could compromise the radon mitigation efforts. This design consideration is therefore essential for ensuring optimal performance of the radon mitigation system and maintaining a healthy indoor environment.