Manual cleaning vs fogging vs electrostatic spray: what each one actually reaches

1. Manual cleaning: excellent at soil removal, blind everywhere else

Wiping is mechanical. It lifts soil, biofilm and organic load off a surface, and nothing else replaces it — a fog will not remove a spill, and no disinfectant works reliably through visible dirt. That is why we never present fogging as a replacement for cleaning. It is the step that comes after it.

But the coverage of a cloth is exactly the area of the cloth, multiplied by the time available and the diligence of the person holding it. On a real ward round or a real night shift, that means the front of the door, the top of the desk, the arm of the chair. Not the underside of the bed frame, not the back of the monitor arm, not the top of the curtain rail, not the vertical face of the wall behind the bin.

The other limitation is repeatability. Two staff cleaning the same room produce two different results, and neither is measurable afterwards. There is no evidence trail beyond a signature on a sheet.

• Removes soil and organic load — essential, and irreplaceable
• Coverage limited to reachable, remembered, visible surfaces
• Result varies by operator, shift pressure and time available
• Treats no air at all

2. Electrostatic spraying: charged droplets that bend around what you aim at

An electrostatic sprayer puts an electrical charge on each droplet as it leaves the nozzle. Two things follow from that. First, the droplets repel each other, so they spread out into an even film instead of landing in fat wet patches with dry gaps between them. Second, they are attracted to the earthed surface in front of them — which means the droplet does not travel in a straight line. It curves. It bends around the edge of a chair leg and lands on the back of it. This wrap-around effect is the whole point, and it is the thing a trigger bottle physically cannot do.

Droplet size matters just as much. A hand spray bottle throws coarse droplets that hit, run and drip, so most of the chemical ends up on the floor rather than working. Electrostatic droplets are 5–50 microns — roughly 1/20th to 1/10th the width of a human hair — which is why the spray behaves as a dry fog. It lands evenly, does not run off surfaces, and is fine enough to settle into the microscopic texture where trigger-spray droplets cannot reach.

Small droplets also get into places a wet cloth simply bridges over. Surfaces that look flat are not: plaster, painted block, grout, laminate scuffs, upholstery weave and carpet pile are microscopically rough, and bacteria, viruses, mould and their spores sit down inside those grains and fibres. A cloth wipes across the peaks. A fine charged droplet settles into the valleys — and that is where the surviving contamination lives after a normal clean.

• Charged droplets are attracted to the surface and curve around edges
• 5–50 micron droplets behave as a dry fog — even coverage without run-off or soaking
• Reaches into the microscopic texture of walls, grout, upholstery and carpet
• Very well suited to targeted work: a soft-furnished room, a vehicle interior, a specific set of equipment
• Still directional — someone has to aim it, and it treats no air

3. Fogging: the only one of the three that treats the air

A Sanondaf fogger does not aim at anything. It converts the disinfectant into a dry mist of droplets fine enough to behave like the air they are suspended in. The mist therefore does what the air does: it circulates, it follows the currents in the room, it drifts under the door of the ensuite, over the top of the cupboard, behind the pipework boxing and into the ceiling void within reach of airflow. Then it settles on every surface in the volume at the same time.

That distinction is the one most people miss. Airborne contamination is not a theoretical problem — it is how a norovirus incident spreads through a home, how a mould spore load moves between rooms in a damp property, how an infectious aerosol lingers in a treatment room after the patient has left. Fogging decontaminates the air in the room as well as the surfaces in it. Manual cleaning cannot do that, and directional spraying only does it incidentally.

Sanondaf's published testing of air-powered fogging devices shows the mist distributes rapidly and evenly through a room volume, which is why cycles are measured in minutes rather than the hours a traditional fumigation needed. The process is documented to achieve up to 99.9999% (6-log) reduction of bacteria, viruses, fungi and spores under validated conditions, and because the chemistry is hydrogen peroxide based it breaks down to water and oxygen, leaving no residue and no waste stream.

• Whole-volume: every surface in the room treated in the same cycle
• Follows air currents into gaps, voids and behind fixed furniture
• Decontaminates the air, not only the surfaces
• Repeatable — the machine does the same thing on every run, whoever presses start
• One 8kg hand-carried machine treats up to five rooms per hour, depending on size

Coverage compared, honestly

The chart below is how we explain the three methods at survey. The percentages are indicative planning figures used to show the shape of the difference — not laboratory measurements — and the exact numbers for your rooms are confirmed when we survey them.

So which one do you actually use?

All three, in order. Clean first to remove soil. Use electrostatic spraying where the job is targeted and soft-furnished or awkwardly shaped. Fog when you need the whole volume and the air treated, evidenced, and handed back quickly.

That is exactly what a leased machine is for. Rather than paying an operator to come out for one room, your own trained staff run the cycle at the end of the shift they were already working — a preventative treatment, not an emergency response. The machine sits on your site and gets used on the rota you already have.

• Clean to remove soil — always first
• Electrostatic spray for targeted rooms, vehicles, upholstery and equipment
• Fog for whole rooms, wards, kitchens, halls and anywhere air movement carries risk
• Every treatment logged and certificated for the compliance file

What it costs per room

Leases start from £450 per month + VAT with the first three months payable up front, on terms up to 36 months, plus a chemical commitment from 100 litres. Spread across the rooms a site actually treats each month, sites typically plan on roughly £10–£12 + VAT per treated room — against a single attended call-out for one room, which is never that.

The saving is not really the chemical or the machine. It is the downtime you stop buying: rooms back in service the same shift, no waiting for a contractor slot, no cancelled bookings, no closed wing.