Respiratory Illness, Indoor Air Quality & What Cleaning Can Do

There is a lot of marketing in this space and very little clarity, so here is the plain version. Cleaning controls what has settled: dust reservoirs, carpet soil, biological growth on wet surfaces, and debris on vent faces. HVAC controls what is airborne: fresh air exchange, filtration efficiency, and humidity.

For respiratory illness transmission, the airborne side dominates. For allergy and asthma symptoms, the settled side matters a great deal, because settled dust gets re-suspended constantly. A building needs both, and any vendor who tells you cleaning alone solves indoor air quality is selling.

Settled dust on ledges, diffuser faces, light fixtures, and overhead structure is the largest reservoir in most buildings, and it re-suspends every time air moves. High dusting with HEPA capture removes it rather than relocating it.

Carpet holds fine particulate deep in the pile — a significant reservoir of allergens including dust mite allergen, pollen tracked in, and skin cells. Vacuuming with genuine HEPA filtration removes it; vacuuming with a poor filter blows the fine fraction straight back into the room, which is why cheap equipment makes air quality worse during cleaning.

Wet areas — restroom and shower grout, floor drains, break room sinks, and any surface with persistent moisture — grow biological material that contributes odour and, in some cases, spores. Those are cleanable and belong on a stated cycle in a Florida building.

At the humidity levels normal here, indoor relative humidity above roughly 60 percent supports mould growth and dust mite populations. Buildings that run their HVAC intermittently — offices closed on weekends, seasonal properties, spaces with oversized cooling that short-cycles — can sit above that threshold for long stretches.

That is a mechanical problem with a cleaning symptom. We will clean visible growth on surfaces where it is within scope, and we will tell you clearly when the pattern points to humidity control rather than cleaning frequency. Cleaning the same mould off the same wall every month is not a maintenance programme; it is a diagnosis being ignored.

Three questions decide most of it. What is the filter rating and how often is it actually changed — MERV 13 is the commonly recommended target for improved particle capture where the system can handle it. How much outside air is the system introducing, and can run time be increased during occupied hours. And is the system controlling humidity, not just temperature, which is a distinct capability.

If a system cannot support better filtration, portable HEPA air cleaners sized to the room are an effective supplement, particularly in waiting rooms, classrooms, and conference rooms.