This company has 120 staff across two floors of an office building, working in open plan with desks close together, six glass meeting rooms, a shared pantry, and central air conditioning circulating air across each floor.

In early September 2026 the company held its quarterly all-hands, bringing staff from both floors into one meeting room from nine in the morning until three in the afternoon, with presentations, a question session, and lunch eaten in the same room.

The following week HR received 23 sick notes for respiratory illness within five working days, close to a fifth of the entire company, and nearly half of the team seated in the zone next to that meeting room.

What the company was already doing, and thought was enough

This company was not careless about hygiene. If anything they did more than a typical office, with cleaners wiping desks, door handles and stair rails with alcohol every morning and every afternoon.

There was hand sanitiser at every entrance, a policy asking anyone with symptoms to work from home, and air filters changed on the building manager's schedule.

But everything on that list addresses pathogens on surfaces that hands touch, which is one transmission route, and not the main route for respiratory pathogens in a closed room where people sit together for six hours.

Respiratory pathogens spread through aerosols that hang in the air and settle across every square metre of a room, not only on the desks people touch. A cloth reaches only a fraction of the actual surface area.

Why wiping falls short in simple area terms

Consider the numbers. A meeting room eight by twelve metres has 96 square metres of floor, but the total surface area in that room, counting walls, ceiling, chairs, curtains, carpet and air vents, is several times greater.

Wiping with a cloth covers horizontal surfaces within arm's reach, which may be under ten per cent of the real surface area. The rest is never addressed at all.

Surfaces nobody wipes include the wall behind the chairs, the underside of tables, upholstered seat fabric, air vents, blinds and the gaps between furniture, all places where aerosols settle and accumulate.

Wiping also takes time. Cleaning one meeting room thoroughly takes about forty minutes, which in practice means cleaners never have time to do it for every room every day.

What it cost the business in those two weeks

The first cost was capacity. The product team seated near that meeting room had seven of fifteen people off at once, so the sprint due to ship slipped by two weeks.

The second was internal confidence. Staff began asking whether the company was doing enough, and requested that group activities planned for the following quarter be cancelled.

The third was clients. Two client meetings were postponed because the responsible team was off, and one client asked directly what measures the company had in place before sending a team to their office.

Management concluded that the cost of those two weeks exceeded a full year of disinfection equipment several times over, and decided to find a method that treats the air and the whole room, not just what hands touch.

What changed once they started ULV fogging

The company began using an AIROFOG U260 ULV cold fogger, treating every meeting room after hours and the open plan area twice a week in the evening once staff had left.

The first thing the facilities team noticed was the time. A medium meeting room takes about three to five minutes to fog, against forty minutes to wipe thoroughly and still not reach everything.

The second was coverage. Droplets of 15 to 30 microns drift and settle on every surface in the room, including walls, under tables, fabric seating and the gaps a cloth never reaches.

The third was the numbers. In the following quarter, days lost to respiratory illness across the company fell noticeably compared with the quarter in which this incident happened.

10 reasons to choose the AIROFOG U260 from World Health Disinfection

1. A 15 to 30 micron droplet size built for disinfection

Droplets in this range stay airborne long enough to distribute across a room and settle evenly on surfaces, which is exactly what wiping and can-spraying cannot achieve.

2. An 800 watt motor delivering consistent air velocity

Consistent air velocity is what keeps droplet size consistent throughout a session, not just in the first minute, which matters when treating several rooms in one round.

3. An adjustable nozzle for different spaces

Glass meeting rooms, open plan areas and store rooms each need different droplet distribution. An adjustable nozzle lets one machine suit them all appropriately.

4. Works with any water-miscible disinfectant

Your organisation chooses the product that meets its own requirements, without being locked to one formulation, and can select something appropriate for occupied workspaces.

5. Designed for indoor use

Unlike thermal foggers, which use heat and suit outdoor work, a ULV cold fogger works without heat and produces no smoke, so it can be used in sealed offices.

6. Fast enough to actually do every day

A medium meeting room takes three to five minutes, which a facilities team can genuinely fit in after hours, unlike thorough wiping that never happens daily in practice.

7. Uses far less product than can-spraying

Because droplets are fine and distribute well, the volume of disinfectant used per square metre is significantly lower than spraying from cans.

8. A brand used by hospitals and laboratories

AIROFOG is a German brand used in hospitals, laboratories and facilities that demand high safety standards, which is a quality reference in itself.

9. Before and after microbial test results available

World Health Disinfection has comparative surface sampling results taken before and after fogging, which organisations can use when communicating with staff and clients.

10. Thai after-sales support

Buying from World Health Disinfection means local guidance on operation and disinfectant selection, parts and servicing in country, rather than a sale and nothing more.

The difference between a ULV cold fogger and a thermal fogger

A thermal fogger uses heat to break disinfectant into a dense, visible fog. It suits outdoor work, drainage channels and dense vegetation, but is unsuitable indoors where smoke detectors are present.

A ULV cold fogger works without heat, using air velocity from a motor to break up the liquid. There is no heat and no smoke, so it can be used in offices, hospitals, classrooms and laboratories.

In droplet terms, ULV produces finer and more precisely controlled droplets, which suits disinfection in enclosed spaces where coverage matters but residue does not.

For organisations that must treat both indoor and outdoor areas, having both types is the answer. If only one is possible for indoor work, a ULV cold fogger is the type that matches the task.

Building a fogging schedule an office can actually keep

Start by ranking spaces by risk. Closed meeting rooms where people sit together for long periods are the highest risk, followed by pantries, toilets and open plan areas.

Set frequency by risk. Meeting rooms should be treated after any heavily attended session, open plan areas once or twice a week, with frequency increased during periods of community transmission.

Choose times when nobody is in the space, generally after hours or before opening, and observe the dwell time stated in the disinfectant documentation before anyone re-enters.

Record every session on a simple form: area, date and time, product and dilution, and who carried it out. That record is valuable when communicating with staff or explaining measures to clients.

Frequently asked questions

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