SSD Series – Sub Slab Blower Systems
General Description
H2K Sub Slab Blower systems are used to prevent intrusion of subsurface vapors such as radon, chlorinated, and petroleum (BTEX) vapors into inhabited buildings. These units are a very common tool in commercial, industrial, and residential developments for new construction and site retrofitting. Sub slab ventilation systems provide a negative pressure underneath the building foundation, which prevents hazardous vapors from entering the building. H2K Technologies has many design options to provide a compact & quiet system, whether the site is large or small. Systems can range from a single blower package to multiple blowers in many locations, connected via radio communication.
Typical Treatment Applications
- Sub-slab depressurization
- Radon Mitigation
- Depressurization of concrete foundations
- Bio venting & bio-pile systems
- Excavation venting
- Remediation systems
- Odor control
- Industrial site redevelopment
- Brownfield redevelopment
- Chlorinated solvent venting
- Hydrocarbon vapor venting
- Building under-pressurization
Design Considerations
H2K offers multiple treatment options that can accommodate a large variety of applications. H2K is able to provide performance modeling to determine sizing based on provided data. Air flow, contaminant concentration, relative humidity, pressure drop and discharge criteria are all factors in determining the proper blower size.
Blower Selection
Sub slab blower systems are typically designed for sub-structure depressurization, sub slab depressurization (SSD), sub slab ventilation (SSV), or drain tile suction. Flow and suction requirements will be determined by the soil composition and will dictate blower design. Sites requiring high flow are generally serviced with centrifugal or radial blowers to provide maximum airflow without much vacuum. High flow sites are more common in locations with more pervious soil or loose fill under and around the slab. Sites requiring higher vacuum are generally serviced with regernerative blowers to provide more suction. High vacuum systems are required when the soil formation is more tightly packed and provides more restriction on air flow. Though high vacuum blowers tend to produce more noise, H2K Technologies provides custom engineered enclosures to reduce noise to an acceptable level.
Enclosure Selection
H2K Technologies has a variety of enclosure options for sub slab depressurization sites requiring either high flow or high vacuum. Our custom welded steel enclosures provide weather protection for system components and sound reduction to minimize site impact. Systems are provided with compact packaging and convenient blower access with a front access panel. Smaller ventilation systems can be designed to fit entirely within a standard control panel to minimize equipment space. Larger systems can be designed to include multiple blowers at different suction points and can be programmed to communicate via wireless signal for easier maintenance monitoring.
System Control Design
H2K’s sub slab blower systems come with many options to aid in ongoing system maintenance. Our custom panel shop is able to provide system controls from very basic on/off control to remote access to allow site monitoring from any internet connection. Options include basic safety controls to protect equipment, alarm/fault autodialers, and cellular connectivity to aid in system maintenance. Remote monitoring is available to allow system check-ins via internet connection to reduce site visits by maintenance technicians.
Sample Projects
High flow sub slab ventilation system
This sub slab ventilation system included a 3 HP centrifugal fan to provide suction of 250 CFM at 18 “wc, mounted in an H2K custom steel enclosure. This system was designed for rooftop installation for new building construction to vent chlorinated solvents produced by a previous industrial application.
High vacuum sub slab depressurization system with moisture removal
This sub slab depressurization system included a 10 HP regenerative blower to provide 280 CFM at 50 “wc, mounted an a sound-reducing enclosure. This system was designed for placement at an existing gas station to prevent gasoline-range vapors (BTEX) from entering the store. A moisture separator was also included with this project, to remove the water vapor extracted under high vacuum.