Fogging Machine Differences

The Difference Between Wet and Dry Fog

When it comes to dry or wet fog produced by foggers, the main difference is the droplet size.

Dry fog usually has droplets that are 10 to 15 microns in diameter. This is because the droplets are so small that they create a seemingly dry fog.

On the other hand, a fog that has droplets that are 20 to 30 microns in diameter is considered wet fog. This fog appears to be wetter and more like a mist than a fog. All fogs whose droplets are above 30 microns are usually mists or sprays, not fogs.

Dry Foggers

So, based on this explanation, wet and dry foggers differ based on the fog they emit.

Most thermal foggers are dry foggers because their mist usually consists of droplets of around 10 microns in diameter. These foggers are perfect when you need to distribute the fog over quite a large area. This is because the smaller particles will be able to diffuse widely and travel quite far thanks to air currents and wind.

The downside to this is that the fog might not thoroughly cover the entire area you wanted to treat. This means that it might be better to fog the area at least two times for more complete coverage.

Wet Foggers

Most cold or ULV foggers can disperse dry and wet fog. Their nozzles allow you to regulate both the spray volume and droplet size within a range of 5 to 50 microns. As long as you keep the droplets small, you’ll get a dry fog (to which the previously mentioned factors will apply).

If you adjust the machine to produce a fog with droplets that are 20 microns or larger, you’ll have a wet fog. These larger droplets are better for applications such as disinfection, mold control, or targeting specific areas with an insecticide. These larger droplets mean that the fog will wet specific surfaces and coat them thoroughly with the chosen solution.


No matter which kind of foggers you use – dry, wet, cold, or thermal – you should experiment to see which droplet size best suits your application purposes. This can also differ based on

  • the weather conditions (very windy places vs. places where the wind is a rarity),
  • the treatment area (indoors or outdoors), and
  • the liquid used (water- or oil-based solutions).

When you take into consideration all these factors and merge them with the knowledge of dry and wet fogs and the different types of foggers, you should find it quite easy to make the right decision as to what type of fogger is best for you.

It will largely depend on what type of disinfectant you’re planning on using. The disinfectant solution should have information on which kind of fogger it should to be used with. But in general, you can use both thermal and ULV foggers for disinfecting purposes.

Our fogging sanitising product can be found here – Surface Shield 

20 thoughts on “Fogging Machine Differences

  1. Abe says:

    Hi, I was hoping to use a fogger to spray disinfectant in a school but they have computers and other electronic items, is there a fogger type that would negate the need to cover computers etc. Like maybe using a dry fogger? Thanks

    • Nick says:

      Hi Abe

      There is no such thing as dry fogging all fog is wet so all Electrical items would need to be either covered or removed

    • Nick says:

      Hi Paul

      A ULV fogger or an electrostatic unit, however it would be a better route to bring in a contractor who has the training in fogging and the correct insurance certifications,
      room need to be fully vacated and time to re occupy would be dependent on individual sites

  2. Reg Brown says:

    We sell and modify e-bikes in an industrial unit. We have a machine and repair workshop, small office and showroom.
    What is the best machine to use when we have members of the public bringing in bikes for repair and trying out our bikes prior to purchasing We sanitise each morning but I do not feel this is enough protection for staff and customers.
    Thank you

  3. Helen says:

    Hi I need some advice …… What would be the best fogging system for filming. I’m part of a film crew for a high end drama and we’d like to fog sets at the end of each day. In your opinion what would be the best for us?

    • Nick says:

      Hi Helen

      Apologies for the delay in replying, the best fogging machine in my opinion would be an electrostatic sprayer, as this will produce a “charged fog that will adhere to all surfaces, so with the likes of our 14 day protective treatment Surface Shield would be perfect.
      Best regards


  4. KEITH VAUGHAN says:

    Hi above you say if you use a wet fogger you have to cover all electrical items and paperwork would you need to do this if you used a dry fogger?

  5. Clare Tovey says:

    Hello, What fogger and disinfectant would be suitable for a coach? The seats are fabric and leather, will the fogger leave a residue? And is there any harm to passengers?

    Thank you for your time


  6. Adrian Cahill says:

    a quick question can you use ULV wet fogger in offices with paper work and computers laying around
    kind regards

    • Nick says:

      Hi Adrian

      simple answer is No, all paperwork needs removing/ covering, all electrical items need removing/covering

      Regards The Solution Team

  7. hayley gray says:

    Hi, I am looking for a fogging machine to disinfect a large area. The area is a children’s indoor soft play area which consists of vinyl and plastic over 3 floors. The area is approx 13 metres by 13 metres. What would you recommend for cleaning and creating a quick turn around for in between different play sessions?

    • Nick says:

      Hi Hayely

      An electrostatic sprayer would probably be your best bet, they charge the solution to make it bond to the surface. although you would still need to clean the surfaces before fogging, we have a new product called Surface shield which offer a 14 day protective coating.

      Hope this helps


      The Solution Team

  8. Tom wright says:

    Thanks, Nick, for the brief intro and info on ‘foggers’. Q. how a does a ‘thermal’ fogger work- is it the same as a ‘wet fogger’ or is there a heating aspect to it? T

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