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-s...