Everything you need to know about foggers
What are mosquito foggers?
Mosquito foggers are devices that spray mosquito repellent or insecticide over a large area, thus allowing for broad-ranging pest control. The repellent is dispersed as droplets so that it can be spread over a larger surface area – and also penetrate those places where mosquitoes are most likely to be hiding (for instance, deep beneath heavy foliage). This is achieved either by heating it to the point where it is transformed into a vapor or by forcing it through some type of nozzle at high pressure.
A mosquito fogger is actually a very simple device. Though there are a number of different types out there on the market, all versions of this device consist of a very small set of components: an insecticide; a carrier liquid or solution for the insecticide; a storage tank or reservoir for the fogging solution (and the fuel if the device runs on one); an atomizing chamber in which extreme heat or pressure is employed to vaporize the fogging solution; a barrel or nozzle for dispersing the pest killer; and a power source for vaporizing the insecticide and dispersing it from the blower.
Based on the technology they use to disperse insecticide, mosquito foggers can be divided into two main categories – thermal foggers and cold foggers.
- Thermal foggers – There are two main types of fogger out there on the market – thermal foggers, which use one of the various heating methods to transform an insecticide from liquid form to a vapor or fog that can be dispersed over a wider area. These types of foggers are perfect for large, open areas – as they run on fuels like propane and butane, they cannot be operated in enclosed spaces, because of the risk of asphyxiation. They generally use a hydrocarbon-based carrier liquid like paraffin oil or diesel. They are also very powerful and efficient, they generate very small droplets – which means they can penetrate hard to access areas – and the fogging mist or spray appears as a highly visible fog which makes it much easier to monitor their output and ensures the correct areas are being sprayed.
- Cold foggers – Cold foggers, or Ultra Low Volume (ULV) foggers as many of them are called, are powered not by fuel but by electricity, but the end result is the same: the conversion of the fogging pesticide into a fine mist which is then dispersed into the surroundings. Most of them work by using an electric motor to force the fogging solution through a nozzle at high pressure so that it is converted into a fine mist or spray. Though safer than thermal foggers, one drawback of cold foggers is that the mist they generate is not as visible as the thick fog of thermal foggers: so you may or may not be able to determine if the spray is going to the desired location. Cold foggers are not quite as efficient as thermal foggers, either, heavier concentrations of the chemical are required to get the same result – though on the other hand, because they are non-thermal not as much of the insecticide chemical is burnt in the process. In addition, they can be used indoors as well as outside because there is not the same risk of asphyxiation with this sort of fogger: the carrier liquid is generally just plain water. By adjusting a flow valve located on the nozzle, you can also alter the size of the droplets emitted by the fogger, achieving either ‘wet’ or ‘dry’ applications.
Advantages of using a fogger
When it comes to mosquito control, mosquito foggers offer many advantages over other pest control methods. To start with, and as we have touched on already, they provide extensive protection against mosquitoes over a large area and in normally hard to reach places.
If you have a big yard full of dense foliage, then mosquito fogging is the perfect solution to your pest control problems.
Disadvantages of using a fogger
Mosquito foggers are not without their drawbacks, however. These include the fact that – in the case of cold foggers, at least – an electric power source is required. Also, as we have seen, thermal foggers cannot be used inside or in any other enclosed space due to the asphyxiation risks involved. Finally, regardless of the type of fogger you opt for,
they do require you to handle and come into contact with some powerful chemicals – great caution must be exercised when using these products, especially if you have children and/or pets.
More about thermal foggers
How do they work?
Thermal foggers utilize heat to vaporize a fogging solution or insecticide, creating a dense mist that can be sprayed through the nozzle or barrel of the fogger onto all manner of surface, and can also penetrate hard-to-reach locations like dense foliage, long grass, under the eaves and floorboards of your house, shed etc. The fogging solution is poured into a storage tank or container usually located below the fogger body; from there the user pumps it through a pipe into the heat assembly chamber at the front of the fogger by pressing a fogging trigger situated on the handle of the device. There it goes through an element or coil that is heated to the point where the fogging solution vaporizes and can be sprayed through the nozzle of the device as a fine mist.
There are two main types of thermal fogger out there on the market – thermal fuel foggers and electric foggers (in this article we will also consider ‘commercial’ foggers, which rely on pulse-jet heating technology to vaporize the fogging solution). Thermal fuel foggers contain a socket on the back of them where you place the fuel tank (usually propane) that heats the element. Electric foggers, by contrast, heat the heating assembly using electric energy (they have an electric cord that needs to be plugged into an external power source).
Main benefits of using a thermal fogger
Compared to other types of fogger, thermal foggers can generate a mist or fog made up of very small particles, as little as 0.5-5 microns. This makes them ideal for targeting smaller insects like mosquitoes that prefer to dwell in hard to reach places, like dense foliage and undergrowth, below the floorboard and eaves of your house, and so on. However, unlike cold foggers where the size of the droplets emitted by the fogger can be controlled by adjusting the airflow of the fogger, it is much harder to control the size of the particles released by a thermal fogger. They will come in a wide variety of sizes.
Thermal foggers are very powerful and efficient; moreover, they generate a thick, white or gray colored fog that is readily visible, and thus you can more easily see what you are doing and if the fog is reaching the places you want it to reach.
Where can they be used
As we have seen, because they play with fire and high temperatures, thermal foggers are not safe to use indoors or in an enclosed space, due to the risk of asphyxiation, nor in areas that contain flammable materials. In addition, in colder weather, there is a risk that the heat assembly of the fogger will not heat up to a point where it completely vaporizes the fogging solution so that pesticide that is still in liquid form will begin to drip from the fogger leaving hard to remove stains on the floors and carpets. Thermal foggers are thus suitable for outdoor use only.
Thermal fogger types:
- Propane Mosquito Foggers – Propane mosquito foggers rely on propane fuel to heat up the element or coil that vaporizes the fogging solution. They come with a canister for attaching the propane tank to the fogging device, so that you can carry your device around with you and go fogging wherever you like: as long as fuel remains in the tank, no external power source is required. Beware though that with many propane mosquito foggers, the propane tanks are sold separately, so if you do end up buying one of these foggers, be sure not to forget to purchase a fuel tank to go with it! Here are the best propane fogger options currently available on the market.
- Electric Mosquito Foggers – Electric thermal mosquito foggers rely on electricity to heat the coil that vaporizes your fogging solution. As they don’t require flammable fuel or the generation of open flame, they are safer to use inside than propane powered foggers, however, it is still not recommended due to the fact that they, too, generate a lot of heat and reach very high temperatures in the process of vaporizing your fogging solution. Electric mosquito foggers come with a power cord that needs to be plugged into an electrical outlet, and they may or may not come with extension cords (which give you more options as to where you use them). Here are the best mosquito fogger products that use electric power to heat an element currently going around.
- Commercial mosquito foggers – We have also included commercial mosquito foggers under the heading of ‘thermal foggers’, as these foggers also rely on the generation of heat to vaporize the fogging solution and create a pesticide mist or fog. Some of them are electric powered, others run on standard unleaded fuel; what sets them apart from the propane and electric foggers considered above, is that they are designed for large-scale commercial fogging operations – like the fogging of warehouses, barns, factories, farms, etc. If you want to start your own commercial fogging business or are the owner of a farm or other large installation, then here are some products you might want to consider buying.
More about cold foggers
How do they work?
Unlike a thermal fogger, a ‘cold’ fogger does not make use of heat to vaporize the fogging solution or pesticide poured into the device. Rather, it employs cold spraying methods, the main one of which is subjecting the fogging liquid to extremely high pressure, which separates it into a mist made up of tiny particles. The power source pumps the fogging solution from a storage tank or reservoir out through a nozzle situated at the front of the fogger, which transforms the fogging liquid into a spray or mist.
As with thermal foggers, cold foggers can run on either fuel or electricity, though by far the majority run on the latter, including the main type of cold fogger, the ULV fogger (as we shall see shortly). Likewise, some cold foggers are compatible only with oil-based fogging solutions, others use only water-based ones, others are compatible with both.
Main benefits of using a cold fogger
One useful feature of cold foggers, is that you can easily adjust the size of the particles emitted by the fogger, simply by altering the rate of airflow (which can usually be done by turning a flow valve located on the device). This is useful if you want to fog different kinds of environment: for example, smaller particles are better for indoor areas as they will remain in the air longer rather than resting on the furniture and fittings, and they also penetrate better into small cracks and crevices underneath the floor etc. In the same vein, small droplets are more appropriate for miniscule insects like mosquitoes, whereas larger bugs may be better eliminated by using larger droplets. Also, you will probably want to use larger droplets when you spray outdoors, as smaller ones are more easily blown away from the targeted surfaces by the wind. If you want your cold fogging device to emit larger particles, then simply increase the air flow; through the fogger whereas if you want smaller ones, you will reduce it. Generally speaking, the size of droplets generated by a cold fogger can range from 5 microns up to 50 microns.
Other benefits of cold foggers include the fact that there is no fire risk with these sorts of foggers and, as we have just seen, they can be used indoors as well as outside (at least in the case of electric cold foggers).
Auto mode of ULV foggers
Cold foggers are often set in auto mode and left to fog an indoor area, so there is no need for a person to operate the fogger in the process. This cannot be done with most propane foggers, because there needs to be a person pressing the fogging trigger constantly. Also, it would not be effective to leave a fogger in a static place for a longer time when fogging outdoors.
Some ULV foggers come with a special flex hose and a handle so you can take it into hands and use it as portable fogger while walking around and fogging harder to reach areas.
Drawbacks of cold foggers
However, cold foggers are not without their disadvantages either. They tend to be more expensive than thermal foggers, less efficient – both in the sense that they require more power to run them, and they require higher concentrations of insecticide to get the same results – and the droplets they generate are not as small as those created by thermal foggers. Also, the fog produced by cold foggers is not nearly as visible as that which comes from thermal foggers, which makes it much harder to monitor whether your fog is going to the places you want it to.
Main type – ULV foggers
The main type of cold fogger by far is the ULV fogger. The centerpiece of this type of fogger is an electric motor which generates and regulates the flow of air and pumps flogging solution from a storage tank located in the fogger body, through the nozzle connected to the end of the fogger. The nozzle converts the fogging solution into a fine spray. As the ULV fogger relies on electricity to power it, it must be within reach of an electrical outlet, whether using extension cords or not. Here is our pick of the top three ULV foggers out there on the market today.
Expert tips for using mosquito foggers
Where and when should you fog?
Mosquitoes come out in full force at dawn and at dusk, so these are the best times to fog your yard etc. As for where to use your fogger, educate yourself concerning the places mosquitoes like to set up their nests; generally speaking, they like dank, dark areas containing plenty of foliage and vegetation cover (think long grass, shrubs, bushes etc) – and any source of standing water is a literal breeding ground for these creatures, whether it be outdoor ponds and pools, bird baths, old watering cans and flower pots filled with water, rain puddles, and the like.
Don’t waste scarce insecticide by going around your yard spraying willy-nilly, focus instead on the areas mosquitoes are most likely to be found and apply the insecticide directly to those areas.
Here are some of the places you will probably end up applying fog to:
- On and under the leaves of plants;
- In and under any shrubs and small bushes in your yard;
- On and around trees, in particular, the treetops where the majority of leaves (read: shelter for mosquitoes) are to be found;
- Tall grasses;
- Outdoor ponds, pools and other sources of standing water;
- Any other dark, dank areas on your property – for example under buildings, within cracks and gaps etc.
Especially in the case of propane or other thermal foggers, you want to spray only in areas that are well-ventilated and contain no flammable material. As we have seen, it is forbidden to use this type of fogger indoors, but if you need to spray an area under your roof, or within any nooks and crannies of the built structures of your property – first ensure the area receives proper ventilation. Also, propane foggers generate a lot of heat – and can sometimes even emit a small fire-ball – so be sure the area you are spraying is clear of any materials that could light on fire.
It should also go without saying that a mosquito fogger is not to be used near food, or around children and pets!
How to use a fogger
There are many different types of fogger out there on the market, and to determine how to use yours’ correctly, you should always look at the instructions that come with your product.
There are some general rules that apply to almost all fogging devices, however, and here are a few of them:
- When fogging your yard, don’t stand too close to the surfaces that are being sprayed. A good rule of thumb is to keep a distance of at least 5 or 6 feet; that way, the fog won’t get blown away in an uncontrolled fashion by any winds or breezes that happen to be present during the fogging; and more insecticide will land on the surface you want to spray;
- Wear protective equipment – at the very least safety goggles and gloves;
- Push down on the spray button once every 3 to 4 seconds as you move around the area to be sprayed, that way you ensure no spot gets left unsprayed;
- If you are fortunate, your device will come with a hose extension that enables you to access hard to reach areas. Make sure you use it because mosquitoes and other pests love to dwell within dense foliage, cracks, crevices etc.
How often should you fog?
This depends on the type of insecticide being used to fog: some products are extremely fast acting – but deliver only very short-lived protection – whereas others are effective at creating an ‘insect barrier’ that repels mosquitoes for a lot longer. Always check the specifications of your product to determine the length of protection it supplies: 6 hours is a common number – more than enough to enjoy an outdoor picnic or barbeque!
What type of chemicals should you use?
Fogging chemicals are often divided into ‘residual’ and ‘non-residual’ chemicals. Residual chemical leaves a long-lasting chemical residue and so are not recommended if will be spraying on and around your plants, and in areas where children and pets are known to wander. They are best suited to uninhabited places like around the eaves of your house, where you can use them to effectively create a barrier between your home and any mosquitoes wishing to intrude upon it. You can also use them indoors, provided once again that there is no children or animals present.
For most outdoor applications, non-residual chemicals are recommended as they have a short half-life and their effectiveness quickly wears away post-application;
What liquid should I use with my fogging pesticide?
This again is dependent on the type of pesticide used, and the fogging device it is used with. Check the specifications contained in the labeling of both products to see if they work best with water-based solutions or oil-based solutions, or can be used with both.
Safety tips of using a fogger
Mosquito foggers, though seemingly innocuous little devices, are not without their hazards; to ensure the safety of you and your loved ones, here are a few little rules you should follow.
- Read the instructions – To get optimal results from your device – and to ensure you are not exposed to any hazards – one of the simplest but most easily overlooked things you can do is to read the instructions that come with your product. These will inform you of how to use your fogger correctly, how far to hold it from your body, which spaces it can be used it, which solutions it is compatible with, what protective equipment you should wear whilst fogging, and suchlike. Any fogging device worth the money you fork out for it will come with a user manual that contains this and similar information.
- Wear protective gear – Most fogging solutions are not strictly speaking poisonous to humans or even pets, however, they can still cause allergic or other harmful reactions if too much comes into contact with your skin or respiratory system in too short a space of time. So when fogging, you should at the very least put on protective goggles, work gloves, long-sleeved shirts and pants, and closed shoes. A respirator may be a good idea as well. Be especially careful when handling the fogging pesticide in concentrated form, which you may do when you are pouring it from the bottle into the storage tank of your fogger.
Beware fuel and flame!
When operating propane and other fuel-powered thermal foggers, you want to be very careful that you don’t expose the fuel directly to open flame, or flammable materials as that can lead to a massive conflagration that can put you at risk of major injury. Similarly, when using electric foggers, make sure that neither the fogger nor the power cord comes into contact with water – you probably already know that electricity and water don’t mix very well!
Mosquito fogger buying guide
When buying a fogger, choose one that is made from high quality, sturdy materials – preferably stainless steel. Especially if you are going to be fogging outside, you want a product that will stand up to all weather conditions, including wind, rain, sleet and scorching summer sun. Look for a product that has a UL or IP (eg IP55 or IP65) waterproof rating, and is also certified as corrosion resistant.
The range of sizes of the droplets generated by your fogger should also be listed on the product specifications contained on the packaging of your fodder. For mosquitoes, you want droplets of 20 microns or less – not only because mosquitoes are very small insects, but also so that the droplets can penetrate the hard to access regions where mosquitoes are known to dwell.
This phrase refers to how much formula is released per minute by your fogging device.
Another thing to look out for is how large of an area will be covered by a given unit of the fogging formulation used with your fogging device. Look for a product that will enable you to get ‘bang for your buck’!
Storage tank size/capacity
If you are conducting large-scale fogging operations, then be sure to buy a device with a large storage tank for the fogging solution. That way, you won’t run out of pesticide halfway through the job!
Fogging solutions that your device can be used with
Some devices are only compatible with water-based solutions, others with oil-based ones – others still can be used equally as effectively with both. Be sure to check this information before buying a fogger, and fogging solution, that doesn’t match!
Weight and dimensions
If you are going to be strapping your fogger to your back and spraying a large outdoor area, you want a lightweight, compact device. Similarly, if you take it with you on camping trips and the like. Be sure to read up on the dimensions – and weight – of the product you have your eye on.
Can your fogger be used to apply disinfectant, conduct odor control activities, treat and prevent mold? Is it suitable for use against other types of pest problems – for example, termites. It might be useful to buy a product with multiple possible applications.