Indoor Air Quality Services for Commercial and Institutional Buildings
Occupant complaints, musty odors, a mold finding in the mechanical room — IAQ problems in commercial buildings almost always run through the HVAC system. Service-Tech brings the HVAC-side expertise most mold contractors don't have.
- NADCAMember since 1990
- 100,000+Facilities serviced since 1960
- 4.9Rated across 111 Google reviews
- Veteran-ownedUS Army veteran ownership since 2019
What Our IAQ Services Cover
Service-Tech's indoor air quality services support commercial and institutional buildings through the full arc of an IAQ problem: assessment coordination and source investigation, HVAC-side mold remediation, hygiene restoration of contaminated system components, and filtration upgrades that harden the system against recurrence. The work is a specialized branch of our Commercial Air Duct & HVAC Cleaning practice — because in commercial buildings, the HVAC system is both the most common amplification site for mold and the delivery network that spreads it.
The Source Is Usually the AHU — the Ducts Are the Symptom
When mold appears at supply diffusers or occupants report musty air, the instinct is to blame the ductwork. EPA guidance on mold in HVAC systems points the other way: mold needs sustained moisture, and in a commercial system the reliably wet locations are inside the air handler — the cooling coil, the drain pan, and the insulation liner around them. Ducts downstream are usually dry; what they carry is spores and fragments shed from the wet source upstream.
This distinction decides whether remediation works. Clean the ducts while leaving a biofilm-loaded drain pan and saturated liner in the AHU, and the "remediated" system re-contaminates itself within weeks — an expensive way to fail. Our assessments therefore start at the moisture: pans, coils, liner condition, humidity control, and any history of water events, then work downstream. It is the assessment-first sequence EPA guidance describes, executed by people who work inside air handlers for a living.
Why IAQ Complaints Deserve an HVAC-Literate Response
An IAQ complaint is data. Clusters of symptoms in one zone point at that zone's air path; building-wide complaints point at a central system; complaints that spike when cooling season starts point at wet-section growth being distributed on schedule. Facility managers in schools, offices, and healthcare settings sit between anxious occupants and vendors with something to sell — testing firms that only test, mold contractors who avoid the mechanical systems, and janitorial vendors out of their depth.
The HVAC-literate response connects the complaint pattern to the system serving it, inspects the moisture locations first, and scopes remediation around the source. That is the role Service-Tech plays — and where third-party testing or clearance is warranted, we work alongside independent assessors rather than grading our own work.
How an HVAC Mold Project Runs in an Occupied Building
Remediation in an occupied school or office rises or falls on containment. Here is what you should expect — from us or any qualified vendor:
- 01
Source investigation
Moisture mapping through the HVAC path: drain pans, coil sections, liner, humidification equipment, and water-event history. The finding drives the scope.
- 02
Containment and negative air
The work area is isolated under negative pressure with HEPA-filtered air machines, so remediation does not become redistribution into occupied zones.
- 03
Source remediation
Contaminated components are cleaned to bare surface; deteriorated or saturated fiberglass liner is remediated or encapsulated; pans are reconditioned so water drains rather than stands.
- 04
System hygiene restoration
Downstream duct cleaning removes the settled spore load the source was feeding — sequenced after the source is corrected, not before.
- 05
Verification and documentation
Post-remediation inspection with photo documentation; where the project warrants it, independent third-party clearance testing before re-occupancy.
- 06
Recurrence prevention
Filtration upgrades, condensate corrections, and humidity-control recommendations so the conditions that grew the problem don't return.
Florida Humidity, Ohio Condensation: Regional Mold Drivers
Mold pressure differs across our service states, and remediation scoped for one climate under-serves the other. In Florida, year-round humidity means HVAC systems fight moisture continuously — oversized units that short-cycle without dehumidifying, wet interior liner, and growth that resumes quickly if moisture control isn't corrected alongside cleaning. In Ohio, the drivers are seasonal: summer condensation on cold surfaces, spring water intrusion, and winter humidification equipment — problems that hide half the year and bloom on schedule. Because Service-Tech crews work both climates from our Ohio and Florida offices, the recurrence-prevention half of our scope is grounded in the actual moisture behavior of your region, not a generic checklist.
Verification: What to Demand Before Re-Occupancy
The remediation industry's weakest habit is declaring victory without evidence. Before accepting any HVAC mold project as complete, a facility manager should hold four documents: a defined scope tied to the source investigation (what was contaminated, and why); photo documentation of remediated surfaces; a written description of the moisture correction — because remediation without moisture correction is a subscription, not a solution; and, where the project's risk warrants it, independent clearance results from a third party with no stake in the answer. We build our deliverable around exactly that file, because it is also what your insurer, your board, or a concerned parent group will ask to see.
When to Call: Triggers for an IAQ Investigation
- Complaint clusters — musty odor, irritation, or symptom reports concentrated in a zone or tracking cooling season.
- Visible growth — on diffusers, in the mechanical room, or found during filter changes.
- After water events — roof leaks, pipe failures, flooding; the clock on wet materials runs in days, not weeks.
- Post-construction — renovation dust and disturbed systems are classic complaint triggers.
- Seasonal humidity problems — spaces that can't hold humidity setpoints are growing something somewhere.
Where the source investigation implicates equipment beyond cleaning — a coil past recovery, saturated liner throughout — the fix escalates naturally into deeper component work: our HVAC coil cleaning and duct-system scopes, including industrial air duct cleaning for plant environments. Buildings tightening their systems after remediation often add Aeroseal duct sealing so unfiltered cavity air stops bypassing the filtration that protects the system.
What IAQ Services Cost
IAQ projects range from a single-zone investigation to multi-AHU remediation, so pricing is scoped per project: Free estimate — quote after site assessment. Travel is factored into the quote across our 150-mile service radius from each office. Schools, offices, and healthcare facilities are our most frequent IAQ clients; see the full range on our industries page.
What Happens If Mold Findings Are Ignored
Unaddressed HVAC mold compounds on three fronts. Biologically, growth spreads through lined systems and wet sections feed the building continuously. Organizationally, occupant complaints escalate — in schools and workplaces, from maintenance tickets to formal claims, sometimes to media attention. Financially, the eventual remediation grows with the colonized area, and deferred moisture correction adds equipment damage to the bill. An early source investigation is the least expensive point on that entire curve.
Get an HVAC-literate assessment of your IAQ problem — source first, scope second.
What an IAQ Programme Measures
- Ventilation rate against standard. ASHRAE 62.1 sets minimum outdoor air rates by occupancy — a building can be spotlessly clean and still under-ventilated.
- Filtration. MERV 8 or better as a floor, with the change interval driven by measured loading rather than a calendar.
- Humidity. Relative humidity held between 30–60%. Above that range you are growing something; below it, occupants complain regardless of particulate.
- Particulate at source. Where the source is the duct system, source removal to the NADCA acceptance figure of 0.75 mg per 100 cm², with capture at HEPA 99.97% of particles at 0.3 micron.
- The air handler, not just the duct. Coil, drain pan and plenum foul first and are the components most often missed; a liner that has begun to shed is encapsulated or replaced rather than cleaned again.
- Programme basis. ASHRAE 180 for maintenance, and NFPA 90A and NFPA 90B for the installation the programme has to leave intact.
Measurement first, then remediation. An IAQ complaint answered with a duct clean and no readings is a guess that happens to cost money.
The Six Readings an IAQ Investigation Starts From
| Reading | Against what | Why it matters |
|---|---|---|
| Outdoor air rate | ASHRAE 62.1 minimum for the occupancy | A clean building can still be under-ventilated |
| Relative humidity | Held between 30–60% | Above it you grow something; below it, complaints regardless |
| Filter grade and loading | MERV 8 or better, loading rate measured | Sets the real change interval |
| Coil pressure drop | The design figure | Quantifies restriction a visual check cannot see |
| Duct surface sample | 0.75 mg per 100 cm², swabbed and weighed | Turns "dusty" into a number |
| Interior condition | Borescope beyond arm's reach | Decides whether the duct is the source at all |
Where the duct system is the source, the remediation is source removal: contamination dislodged and extracted under continuous negative pressure with HEPA capture at 99.97% of particles at 0.3 micron, a shedding liner encapsulated or replaced, fins straightened, and everything reinstated and pressurized. Measurement first — an IAQ complaint answered with a duct clean and no readings is an expensive guess.
In Short
ASHRAE 62.1 sets the minimum outdoor air rate by occupancy; ASHRAE 180 sets the maintenance programme; NFPA 90A and NFPA 90B govern the installation. Hold relative humidity between 30–60% and filter at MERV 8 or better. Where the duct system is the source, source-remove to 0.75 mg per 100 cm² with capture at HEPA 99.97% of particles at 0.3 micron, encapsulate or replace a shedding liner, and read coil pressure drop against design. The DOE attributes 25–40% of commercial heating and cooling energy to contamination and airflow restriction.
Frequently Asked Questions
Does mold in air ducts mean the whole system is contaminated?
Not necessarily — and ducts are often the symptom rather than the source. Mold needs sustained moisture, which in commercial systems means the AHU wet section: coil, drain pan, and surrounding liner. A proper investigation starts there; if the source is corrected, downstream duct cleaning completes the remediation. Cleaning ducts while leaving a wet source all but ensures recurrence.
Can the building stay occupied during HVAC mold remediation?
In most cases, yes. Work zones are isolated under negative pressure with HEPA-filtered equipment, and projects are staged by zone and scheduled around occupancy — nights, weekends, and breaks in schools. Containment discipline is the difference between remediation and redistribution, and it is the first thing to evaluate in any vendor.
Do you test for mold, or should testing be independent?
Source investigation and inspection are part of our scope, but where a project warrants clearance testing, we support using an independent third party — a firm with no stake in passing its own work. That separation protects you, and the independent clearance report is the document your stakeholders will trust.
When does mold in an HVAC system require professional remediation?
EPA guidance draws the line at the system itself: growth inside HVAC components — coils, liner, pans, ductwork — calls for professional remediation because disturbance without containment spreads spores building-wide, and porous materials like fiberglass liner cannot simply be wiped clean. Visible growth, musty odor tied to system operation, or complaint clusters are all triggers to investigate.
How much do commercial IAQ services cost?
Scope varies enormously — from a single-zone source investigation to remediation across multiple air handlers — so every project is quoted after a site assessment. The estimate is free, and travel across our 150-mile service radius is factored into the quote. Early investigation is consistently the least expensive point to engage.