Air Scrubbing and HEPA Filtration — Salt Lake City Restoration
Air scrubbing and HEPA filtration control the airborne particulate that is generated during every restoration project involving demolition, cleaning, or containment. Removing wet drywall throws mold spores into the air. Cleaning smoke residue releases particulate. Extracting sewage releases aerosolized bacteria. Cutting damaged materials generates dust that carries whatever contamination was on the material. Air scrubbing is the technical response — HEPA-filtered fans (99.97% capture efficiency at 0.3 microns) that draw contaminated air through the filter, exhaust cleaned air, and progressively reduce airborne particulate concentrations during and after the work. Vivid Water Damage & Restoration deploys air scrubbing on every containment project and most non-contained projects where airborne particulate control matters.
What HEPA Actually Means
HEPA (High-Efficiency Particulate Air) is a filtration standard defined by U.S. Department of Energy specification DOE STD 3020 and by international IEC 60335-2-69 and EN 1822 standards. A true HEPA filter captures 99.97% of particles at 0.3 microns diameter — the size that is hardest to capture (larger particles are trapped by direct impaction; smaller particles are trapped by diffusion; 0.3 micron is the most-penetrating particle size).
Not every product labeled “HEPA-like” or “HEPA-type” meets the true HEPA standard. IICRC S520 (mold remediation), S500 (water damage), and S700 (fire and smoke damage) all require true HEPA-rated equipment on containment projects — consumer-grade filtration or industrial shop-vac filters do not qualify. Vivid uses commercial-grade HEPA equipment certified to the DOE STD 3020 standard on every project.
Standard Air Scrubbing Equipment
Portable HEPA Air Scrubbers
Commercial HEPA air scrubbers (Dri-Eaz DefendAir HEPA 500, Phoenix Guardian R HEPA System, Novatek Piranha, or equivalent) are the standard equipment. Specifications vary by model:
- Airflow: 500–2,000 cubic feet per minute (CFM) at rated backpressure
- Filter stages: pre-filter (large particulate), MERV 13 secondary (fine particulate), true HEPA final (0.3 micron 99.97% capture)
- Power draw: 5–15 amps at 120V, allowing multiple units on standard residential circuits
- Optional activated carbon stage for volatile organic compound (VOC) capture on fire and biohazard projects
Negative Air Machines
Similar HEPA-filtered fans configured to exhaust cleaned air outside the containment through flexible ducting. This creates the negative-pressure differential (typically −5 Pa or greater) that prevents contaminated air from escaping the containment perimeter into occupied areas.
In-Duct HEPA Filtration
For HVAC-integrated cleanup where the whole ductwork system must be filtered without shutting down the HVAC, temporary in-duct HEPA cartridges install at the return plenum or supply plenum during the cleaning phase.
The Air Changes Per Hour (ACH) Calculation
Air scrubbing effectiveness is measured in air changes per hour (ACH) — the number of times the total air volume in the space is drawn through HEPA filtration per hour. Standard requirements:
- IICRC S500 water damage projects: 3–5 ACH typical for containment areas during drying and demolition phases
- IICRC S520 mold remediation: 4–6 ACH standard, 6–10 ACH for Stachybotrys and heavy Condition 3 projects
- IICRC S700 fire and smoke: 4–8 ACH during structural cleaning, higher during heavy soot removal
- Biohazard and Category 3 sewage: 6–10 ACH with negative pressure verified at all containment boundaries
ACH is calculated as (CFM × 60) ÷ (cubic feet of containment volume). Example: a 500-CFM HEPA scrubber in a 12 ft × 15 ft × 8 ft containment (1,440 cubic feet) produces (500 × 60) ÷ 1,440 = 20.8 ACH — well above minimum requirements. A 1,000-CFM scrubber in a 30 ft × 20 ft × 10 ft containment (6,000 cubic feet) produces 10 ACH. Vivid sizes equipment for the specific containment volume and target ACH on each project.
Negative Pressure Verification
On containment projects, air scrubbing is combined with negative-pressure differential to prevent airborne contamination from escaping to occupied areas. Vivid verifies negative pressure with a Testo 510 digital manometer at the containment perimeter, targeting −5 Pa or greater relative to the surrounding area. Continuous monitoring during work catches any breach of the containment integrity — a torn dust barrier plastic, a leaking airlock zipper, an unexpected door opening — that could allow contamination migration.
When Air Scrubbing Is Required
Always Required
- Category 3 sewage cleanup (per IICRC S500 Section 12.2)
- Condition 3 mold remediation (per IICRC S520 Section 12)
- Biohazard cleanup involving trauma, unattended death, or infectious disease
- Fire damage cleaning with heavy soot or wet smoke residue
- Demolition of asbestos-containing materials (requires additional asbestos-specific credentials)
Sometimes Required
- Category 2 grey-water cleanup where airborne bacterial concentration may be elevated
- Small mold projects (Condition 3 under 10 square feet) where full containment isn’t practical but airborne particulate control still matters
- Contents cleaning in enclosed spaces where dust concentration would be high without ventilation
Not Typically Required
- Category 1 clean-water losses with no visible mold, no smoke, and no biohazard exposure
- Standard drying projects where no demolition is occurring
- Reconstruction phases after post-remediation clearance
Air Scrubbing on Wildfire Smoke Intrusion
Salt Lake County summer wildfire smoke events produce interior particulate deposition that persists after outdoor smoke clears. Vivid deploys HEPA air scrubbing as a standalone service for wildfire smoke cleanup, running 4–7 days depending on the interior particulate load. Post-wildfire air quality assessment (measured with a Testo 610 particulate counter comparing PM2.5 and PM10 concentrations before and after treatment) documents the effectiveness of the scrubbing.
Frequently Asked Questions
- Can I use my regular HVAC system to filter the air instead of running HEPA scrubbers?
- No, in most restoration situations. Standard HVAC filters (MERV 8–11 typical for residential systems) capture 20–65% of 0.3-micron particles — not the 99.97% required by IICRC standards. The HVAC filter also isn’t designed to handle the heavy particulate load from restoration work; it will clog rapidly and reduce HVAC performance. On restoration projects, the HVAC system is typically shut down and sealed off from the affected space to prevent particulate migration through ductwork. Post-remediation HVAC restart is only after post-remediation verification confirms the space is clear.
- How long do the HEPA filters last, and how are they disposed of?
- Filter life varies by project intensity. On heavy Category 3 or mold projects, primary HEPA filters may need replacement every 5–10 days. On standard water damage drying projects, filters can last 30–60 days between changes. Loaded filters are considered contaminated by whatever the project was addressing — mold spores, sewage bacteria, smoke particulate — and are disposed of as regulated waste on biohazard and Category 3 projects, standard construction waste on water damage and mold projects.
- Is HEPA air scrubbing loud?
- Commercial HEPA scrubbers produce 55–70 dB at operating speed — comparable to a running dishwasher or moderate traffic noise. On occupied spaces where clients remain in the home during restoration, scrubbers are typically located in the affected space (behind containment) rather than in occupied rooms to minimize noise impact. Overnight operation is standard on projects where 24-hour scrubbing is required for ACH compliance.
- Can HEPA scrubbing remove chemical odors and VOCs, or only particulate?
- Particulate only with standard HEPA filtration. Chemical odors and volatile organic compounds (VOCs) pass through HEPA filters unaffected because they are gas-phase molecules smaller than the filter can capture. Activated carbon secondary stages (added to some HEPA scrubbers, or run in parallel with carbon-only units) address VOCs and odor. For heavy VOC or odor loads, Vivid combines HEPA scrubbing (for particulate) with hydroxyl generation or ozone treatment (for odor). See the odor removal services page.
- Is HEPA air scrubbing part of the standard project cost, or a separate line item?
- Standard equipment on containment projects — sewage cleanup, mold remediation, biohazard cleanup, and heavy fire damage projects — where it is a required component of the IICRC-compliant protocol. Equipment costs are typically integrated into the overall project scope rather than billed separately. On standalone air scrubbing services (wildfire smoke cleanup, indoor air quality remediation without other restoration work), equipment rental typically runs $75–$150 per unit per day plus filter replacement costs.
Contact Vivid Water Damage & Restoration — Salt Lake County Emergency Response
Vivid Water Damage & Restoration deploys HEPA air scrubbing on every containment project and offers standalone air scrubbing services for wildfire smoke intrusion and indoor air quality remediation.
- Emergency Line (24/7): (385) 289-3885
- Address: 7084 S 2300 E #170, Salt Lake City, UT 84121
- License: Utah DOPL general contractor license #10894576-5501
- Certifications: IICRC WRT, ASD, AMRT, FSRT, OCT, HST; EPA Lead-Safe RRP
Office Hours
- Emergency Service: 24 hours a day, 7 days a week
- Office Staff: Monday – Saturday, 9:00 AM – 5:00 PM
- Closed: Sundays and major holidays (emergency line always active)