What Is Dry Fog and How Does a Dry-Fog Generator Work?

Dry fog is a glycol-based disinfectant liquid atomized into particles measuring just 5–20 microns. The particles are so fine that they behave like a gas rather than moisture — they fill the entire cabin, penetrate the vents, and bind odor molecules right at their source. The result is a fresh, dry, streak-free car with no leftover moisture or residue. Unlike a spray bottle or an ozone generator, dry fog acts on every surface at once and needs no drying time afterwards.

What is dry fog?

The name dry fog (Russian сухой туман, Estonian kuivudu) reflects the key point: unlike steam or a spray bottle, it leaves surfaces dry. Inside the generator the liquid is broken into an ultra-fine aerosol with a particle size of 5–20 microns. For comparison, a human hair is roughly 70 microns thick.

Particles this small:

• float in the air for minutes, like a gas;
• penetrate everywhere — air ducts, the A/C evaporator, fabric fibers, and under the carpet;
• do not settle as heavy droplets, so they leave no moisture, stains, or streaks.

How does a dry-fog generator work?

A dry-fog generator, or fogger, turns the liquid into a fog-like aerosol and releases it into the cabin. A typical treatment looks like this:

1. Fogging — the device runs for about 45–60 seconds, filling the cabin with dense dry fog.
2. Dwell time — the car is left sealed for 15–20 minutes so the fog reaches every corner and binds the odor sources.
3. Airing — the doors are opened for a couple of minutes and the car is ready to use.

During the dwell time the fog reaches places no cloth or spray can: the A/C evaporator, the ventilation ducts, and the gaps between the seats — exactly where most bacteria and bad smells accumulate.

Thermal fogger vs cold fogger: what is the difference?

There are two main types of dry-fog generator. A thermal fogger heats the liquid into a dense, visible fog, while a cold (ULV) fogger atomizes it with air pressure and no heat at all.

Feature	Thermal fogger	Cold / ULV fogger
How it works	Heats liquid into fog	Air pressure atomizes liquid
Particle size	~10 microns	5–30 microns
Uses heat	Yes	No
Fog density	Very dense, visible	Finer and lighter
Best suited for	Fast jobs, workshops	Indoors, the safest option

Does dry fog mask odors or destroy them?

This is the main difference from an air freshener: dry fog does not cover one smell with another. The glycol-based particles bind and neutralize odor molecules right at the source — whether that is tobacco, pets, mold, sweat, or food. Because the fog also reaches the evaporator and the ducts, the smell is removed where it actually forms instead of returning a few days later.

Dry fog also destroys bacteria, fungi, and mold. A proper treatment removes up to 99% of bacteria, so the cabin is not only fresher but also more hygienic. That matters most for shared and rented cars, taxis, and family vehicles, where many different people use the same interior.

Is dry fog safe for your health?

Used correctly, dry fog is safe for your health and for the car. The treatment is done in an empty vehicle, and the short airing after the dwell time means the cabin is ready immediately. Because the process leaves no moisture behind, there is no added risk of mold or corrosion to the electronics.

One important point: in the EU, disinfectant liquids fall under the Biocidal Products Regulation (BPR, EU 528/2012, Product-Type 2). Always choose certified products and follow the manufacturer's instructions — this is what ensures both safety and genuine disinfecting performance.

What odors and problems does dry fog remove?

Dry fog is used when ordinary cleaning is no longer enough. Because the aerosol reaches every surface and cavity, it works against a wide range of sources:

• tobacco and smoke smell trapped deep in the fabrics and the headliner;
• pet odors and the smell of a wet dog;
• mold and mildew caused by a damp cabin or a clogged A/C drain;
• food, spilled drinks, and sweat absorbed into the seats and carpets;
• the musty air-conditioning smell produced by bacteria on the evaporator.

A single treatment takes only about 20 minutes from start to finish, which makes it practical for detailing studios, car washes, and self-service terminals. For heavy or long-standing odors, the process can simply be repeated without harming the car.

Where can you get dry-fog equipment and liquids?

CarFog OÜ supplies dry-fog equipment — portable and thermal foggers, dry-fog generators, and self-service vending terminals — together with certified liquids across all of Estonia. Beyond selling devices, CarFog OÜ also helps set up a complete self-service business, including servicing and training.

In short, dry fog is a fast, dry, residue-free way to disinfect a car interior and eliminate odors — working exactly where ordinary cleaning cannot reach.