Sub-Slab Depressurization Systems and Sub-slab depressurization System Installation

 Sub-slab depressurization systems first began in the early 1990s to fix radon gas problems in homes. The sub-slab system uses a fan or blower attached to pipes placed in shallow pits below a building floor slab and drains the vapors into the atmosphere. The process stops vapors from entering occupied areas. 

 The amount of negative pressure required depends on two main site conditions: 

1) airflow in the material instantly beneath the slab; and 

2) airflow and pressure variations created by the building heating and air-conditioning systems. 

An SSD system needs a relatively low vacuum, so blower sizes tend to be much cost-effective per building area included. On checking the complete site, the engineer conducts a design test to verify that the SSD will extract air from beneath the slab. The design test is a small-scale mock-up of a full-scale system through which small diameter extraction and monitoring points are connected.  

Sub-slab depressurization system installation is reasonably priced. Sometimes the installation is higher. Some factors that can cause installed costs to be on the higher are:

• Highly changeable subsurface conditions;
• High soil moisture or high groundwater table;
• Vapors that require treatment before discharge to the atmosphere (but this is uncommon);
• Unique construction for piping systems;
• Larger blowers, condensate removal, specialized mechanical systems, upgraded or explosion-proof electrical systems, and more advanced controls; and
• Retro-fit necessities of existing buildings.

In the sub-slab depressurization system, installation holes are created in the slab. A suction pit is created by removing a little soil from underneath the section. Post this process; vertical suction funnels are placed into the openings. The pipes are linked with a web containing vapor & exhaust fans, which are eventually released outwards. 

A smaller building requires lesser suction pits than large buildings. 

The process in the installation includes:

1. Pilot Testing
2. Drilling
3. Vapor Collection
4. Installing Pipes
5. Sealing 
6. Venting
7. Exterior Termination
8. Monitoring

The Sub-slab depressurization system process is a cost-effective and simple approach to lessen vapor intrusion. Still, the collection of critical data and basic design parameters are essential steps to assure successful operation.