LOCATING THE SUCTION POINT
Sub-slab connectivity is a very important consideration in locating the suction point. We just completed the design and installation of a sub-slab depressurization system where we evaluated three suction points. It was the third suction point that yielded acceptable connectivity across the sub-slab. As the saying goes, the third time was the charm.
But connectivity, while top of the list, is not the only consideration in locating a suction point. While a central suction point is nearly always preferable from a connectivity stand-point, it is possible (indeed likely), that a radon fan in the middle of the basement won’t work with the finished basement, or the plans for future finishing.
What about power? While most radon fans are very energy-efficient, they still need a power source. If a receptacle is not located nearby, a licensed electrician will be needed to run a new receptacle or hardwired the fan.
Discharge is another consideration. Maintaining the required discharge clearances for the radon fan can quickly restrict discharge location options. Windows, gas meters, air intakes, doors, are all players in determining where a radon mitigation system can discharge.
Underground utilities can pose a concern. In-floor heating must be identified and located before any holes in the slab are advanced. GENERALLY, the sewer and water service are below the slab and covered with gravel. The caps on “generally” is not a typo and I will have more to say on this next post.
There is a significant amount of thought and planning that goes into locating a suction point. It is a matter of balancing what is best for depressurization with what is best for the use of the space above the slab.