Service
Commercial Radon Mitigation in San Diego County
Building-scale radon reduction that accounts for HVAC pressure, occupancy zones, and large-footprint slabs.
Commercial mitigation is a different discipline from residential work. The slabs are larger, the mechanical systems are stronger, and the pressure inside the building is actively managed by equipment rather than left to nature. That changes both the diagnosis and the fix.
A large building can have zones with completely different radon behavior. A ground-floor suite under negative pressure from an exhaust-heavy tenant can measure several times higher than an adjacent suite on the same slab. Measuring one point and treating it as representative is the most common mistake in commercial radon work.
Solutions frequently combine sub-slab depressurization with adjustments to the building's ventilation balance, since the HVAC system may be creating the very pressure difference pulling gas indoors.
Why this work matters
- Employees and students occupy ground-floor spaces for thousands of hours a year, which is comparable to residential exposure.
- Building owners carry duty-of-care responsibilities for indoor environmental conditions.
- Elevated radon discovered during due diligence can delay or reprice a commercial transaction.
- Childcare centers and schools warrant special attention because of the population served.
Signs this service applies to your building
- Any tenant space measuring at or above 4.0 pCi/L.
- Ground-floor or below-grade occupied areas such as records rooms, gyms, or break rooms.
- Buildings with strong exhaust loads: commercial kitchens, labs, salons, or fitness facilities.
- Elevator pits, utility tunnels, and mechanical rooms connected to occupied space.
- A large slab poured in phases with construction joints between sections.
- Pending sale, refinance, or tenant improvement work requiring environmental documentation.
How the process works
- 1
Multi-point building survey
Continuous monitors are deployed across zones, floors, and tenant spaces simultaneously so variation across the footprint is visible rather than averaged away.
- 2
HVAC and pressure assessment
Supply and exhaust balance, outdoor air fraction, and zone-to-zone pressure relationships are documented, since mechanical imbalance is often a primary driver.
- 3
Sub-slab diagnostics at scale
Multiple test holes across the slab establish how many independent pressure fields exist under the building.
- 4
Engineered system design
Fan selection, riser locations, main and branch pipe sizing, roof penetrations, and electrical coordination are drawn before work begins, with attention to tenant disruption.
- 5
Phased installation
Work is sequenced around occupancy, often after hours, with dust control and coordinated shutdowns for slab penetrations.
- 6
Commissioning and verification
Pressure field extension is confirmed at points across the slab, and post-mitigation testing repeats the original multi-point layout for a direct comparison.
Equipment and materials involved
High-capacity radon fans
Larger fans or multiple fans in parallel to serve extended pipe networks.
Manifolded PVC riser network
Main trunk lines with balanced branches so each suction point receives adequate vacuum.
Digital manometers with alarm contacts
Provide facility staff with fault indication and, where desired, building automation integration.
Multi-unit continuous monitors
Simultaneous deployment across zones for a coherent building picture.
Balancing dampers
Allow branch airflow to be tuned after installation rather than fixed at design.
What you get out of it
- Documented indoor air quality improvement across occupied zones.
- Reduced liability exposure for owners and property managers.
- Environmental documentation that supports transactions and lease negotiations.
- Monitoring that alerts facility staff to failures before occupants are affected.
- Systems designed for service access, so maintenance does not require tenant disruption.
San Diego County considerations
San Diego's commercial inventory includes a great deal of single-story tilt-up and slab-on-grade construction, where large uninterrupted floor areas sit directly on native soil.
Mixed-use and multifamily projects across Mission Valley, downtown, and the North County corridors place occupied space directly over podium slabs and subterranean parking, both of which create soil gas pathways.
Coastal humidity and inland heat drive very different HVAC strategies within the same county, and each affects building pressure differently.
Older converted industrial buildings, common in North Park and the neighborhoods flanking it, frequently have patched slabs and utility trenches that behave as direct soil gas conduits.
Frequently asked questions
How is commercial testing different from residential?+
Scale and simultaneity. Residential testing usually involves one or two devices in the lowest occupied level. Commercial testing deploys monitors across every ground-contact zone at the same time, because the pressure environment varies room to room based on HVAC operation. Testing is also normally conducted under normal operating conditions rather than closed-house conditions, since that is how the building actually runs when occupied.
Can the HVAC system alone fix the problem?+
Sometimes, partially. Increasing outdoor air and correcting a negative pressure imbalance can meaningfully lower concentrations in a space that was being actively depressurized. It is rarely a complete answer on its own because it treats dilution rather than entry, and it adds conditioning load year round. The durable solution is usually sub-slab depressurization with HVAC correction as a supporting measure.
Will installation disrupt tenants?+
It is planned so that it does not. Slab coring and interior riser work are typically scheduled after hours or over weekends with negative-pressure dust containment. Exterior pipe routing and roof penetrations can usually proceed during business hours. A phased schedule shared with property management ahead of time avoids surprises.
How long do commercial systems last?+
The piping is essentially permanent. Fans are the wear item and generally need replacement on a multi-year cycle, sooner for high-capacity units running against significant static pressure. Buildings with monitored manometers or alarm contacts catch failures immediately, which is why they are recommended on any system where no one walks past the fan regularly.
Do schools and childcare facilities have different expectations?+
The measurement standard is the same, but the diligence expected is higher. Testing every ground-contact classroom and occupied room individually is the accepted approach, along with retesting on a defined schedule and after any HVAC modification. Because occupancy is dense and the population is young, most operators choose to mitigate at levels below the 4.0 pCi/L action threshold.
Related reading
Related services
Available throughout the county
- Commercial Mitigation in San Diego
- Commercial Mitigation in La Jolla
- Commercial Mitigation in Del Mar
- Commercial Mitigation in Carlsbad
- Commercial Mitigation in Encinitas
- Commercial Mitigation in Poway
- Commercial Mitigation in Escondido
- Commercial Mitigation in Chula Vista
- Commercial Mitigation in El Cajon
- Commercial Mitigation in La Mesa
- Commercial Mitigation in Santee
- Commercial Mitigation in National City
- Commercial Mitigation in Coronado
- Commercial Mitigation in Imperial Beach
- Commercial Mitigation in Pacific Beach
- Commercial Mitigation in Mission Valley
- Commercial Mitigation in Clairemont
- Commercial Mitigation in Mira Mesa
- Commercial Mitigation in Rancho Bernardo
- Commercial Mitigation in Rancho Peñasquitos
- Commercial Mitigation in Carmel Valley
- Commercial Mitigation in University City
- Commercial Mitigation in Point Loma
- Commercial Mitigation in Hillcrest
- Commercial Mitigation in North Park
- Commercial Mitigation in South Park
- Commercial Mitigation in Ocean Beach
Not sure where to start?
Testing is the first step. Send a note describing your home, its foundation type, and any test results you already have.