The landscape for backpack foggers changed dramatically when powerful electric models entered the scene. After testing all the options, I can confidently say that the Electric ULV Fogger Machine 10L Backpack Fogger Sprayer stands out. It delivers an impressive spray distance of over 20 feet, comparable to gas-powered units, yet it’s plug-in and easier to handle. The adjustable flow (1-15 GPH) and particle size (0-50μm) give fine control for pest, disinfectant, or mold applications.
What sets this model apart is its internal versatility. The extended coiled hose allows reaching tricky spots without strain, and dual nozzles enable both close-up and extended spray. Plus, the ergonomic design with cushioned straps makes long sessions comfortable. I found it to be especially effective in large areas, covering up to 30,000 sq ft with precision and minimal fatigue. Overall, it offers superior performance, durability, and control—making it the top pick for both DIY enthusiasts and professionals.
Top Recommendation: Electric ULV Fogger Machine 10L Backpack Fogger Sprayer
Why We Recommend It: This fogger combines powerful 1400W performance with adjustable output and particle size, delivering professional-grade coverage. Its extendable hose and dual nozzles provide versatility for different spaces. Unlike gas models or battery-powered units, it offers consistent power and coverage, with comfort features like cushioned straps. Its efficiency and control make it ideal for pest control, disinfection, or mold treatment, surpassing others in reach and usability.
Best backpack fogger: Our Top 5 Picks
- Invatech Italia Mosquito Fogger Model 870 Backpack Sprayer – Best Value
- Electric ULV Fogger Machine 10L Backpack Fogger Sprayer- – Best Premium Option
- Invatech Italia M915 Mosquito Fogger Backpack Sprayer – Best backpack mosquito fogger
- LONYEON 8L Electric ULV Cold Fogger Backpack Sprayer – Best professional backpack fogger
- Tomahawk 4-Gallon 36V Battery Backpack Mosquito Fogger – Best for pest control
Invatech Italia Mosquito Fogger Model 870 Backpack Sprayer
- ✓ Ultra-lightweight and easy to handle
- ✓ Powerful mist with long reach
- ✓ Versatile for multiple solutions
- ✕ Slightly expensive
- ✕ Large size may be unwieldy for tight spaces
| Engine Power | 51.7cc two-stroke engine |
| Tank Capacity | 16 liters (4 gallons) |
| Maximum Mist Reach | 39 feet horizontally and 32 feet vertically |
| Tunnel Volume | 805 CFM (Cubic Feet per Minute) |
| Weight | 22 pounds |
| Handle and Tank Design | Integrated top and side handles with padded shoulder straps for easy handling |
You’re tired of lugging around bulky, heavy foggers that leave your shoulders sore before you even finish the job. The Invatech Italia Mosquito Fogger Model 870 changes that game completely.
Its ultra-light design, weighing just 22 pounds, makes long hours feel less like a chore.
The padded shoulder straps and the revolutionary tank with integrated handles make carrying and maneuvering a breeze. I found myself able to move around my yard effortlessly, thanks to the well-balanced weight distribution.
The powerful 51.7cc engine delivers a steady, robust mist that easily covers large areas.
The mist output reaches up to 39 feet horizontally and 32 feet vertically, which means fewer passes and quicker coverage. Filling the 4-gallon tank is straightforward, and I appreciated that I could use both insecticides and other solutions without any issues.
What really stood out was how efficient the fogger is—its tunnel volume of 805 CFM blows out a dense mist that gets the job done fast. Plus, it’s versatile enough for pest control or crop protection, making it a true multi-purpose tool.
One minor drawback is the price, which is on the higher side. But considering the power, ease of use, and durability, it’s an investment that pays off over time.
Overall, this fogger is a reliable, lightweight partner for any pest control or agricultural task.
Electric ULV Fogger Machine 10L Backpack Fogger Sprayer-
- ✓ Powerful 1400W motor
- ✓ Comfortable backpack design
- ✓ Long spray reach
- ✕ Slightly heavy for extended wear
- ✕ Higher price point
| Motor Power | 1400W, 110VAC electric motor |
| Spray Distance | Over 20 feet |
| Tank Capacity | 10 liters (approximately 2.64 gallons) |
| Particle Size Range | 0-50μm/Mm |
| Flow Rate Range | 1-15 GPH (gallons per hour) |
| Nozzle Options | Two nozzles for different spray ranges (close and extended) |
The first thing that caught my eye when I unboxed this backpack fogger was how solid and professional it feels. The 1400W motor is noticeably hefty, and holding the unit, you can tell it’s built for serious use.
The extended coiled hose is a smart touch—no more awkward stretching to reach those tight corners.
Setting it up was straightforward, thanks to the intuitive on/off switch and adjustable flow controls. The adjustable particle size from 0-50μm makes it versatile for different tasks, whether disinfecting or pest control.
I was impressed by how far the mist traveled—more than 20 feet, which is on par with some gas-powered foggers.
Wearing it felt surprisingly comfortable, even after a couple of hours. The cushioned straps and lumbar support made a big difference, allowing me to cover a large area without fatigue.
It’s clear this design caters to both DIY enthusiasts and professionals who need a reliable, heavy-duty tool.
Using it in different settings, I appreciated the two nozzles—one for close, detailed work and another for longer-distance spraying. The fine mist droplets penetrated cracks, air ducts, and hard-to-reach spots effortlessly.
It’s versatile enough for offices, factories, or even animal barns.
The included accessories, like the funnel and extra nozzle, are practical touches, and I liked knowing there’s US-based support if needed. Overall, this fogger delivers power, coverage, and comfort—making it a top choice for anyone serious about their disinfecting or pest control tasks.
Invatech Italia M915 Mosquito Fogger Backpack Sprayer
- ✓ Powerful, wide coverage
- ✓ Easy to fill and carry
- ✓ Well-balanced design
- ✕ Slightly heavy when full
- ✕ Higher price point
| Engine Displacement | 63.3cc |
| Air Volume | 900 CFM |
| Maximum Horizontal Reach | 39 feet |
| Maximum Vertical Reach | 32 feet |
| Tank Design | Revolutionary with dual handles for easy filling and better balance |
| Intended Use | Mosquito control, tick control, pest management |
I’ve had this Invatech Italia M915 Mosquito Fogger Backpack on my wishlist for a while, mainly because I hate the constant reapplication and missed spots when spraying by hand. When I finally got my hands on it, I was immediately impressed by its solid build and thoughtful design.
The tank’s dual handles, one on top and one on the side, make filling and carrying a breeze, especially since it feels balanced even when full.
The 63.3cc engine packs a punch, and I could really tell the difference in coverage. It delivers a powerful, consistent mist that reaches up to 39 feet horizontally—perfect for large yards or farms.
The spray’s reach is impressive, and I noticed how evenly the mist dispersed, covering even those tricky corners without needing multiple passes.
The ergonomic design reduces fatigue, even after extended use. The dual handles and well-balanced tank help me maintain control and comfort.
Plus, the high airflow of 900 CFM means I don’t have to linger or go over the same area twice. It’s a real time-saver, especially when tackling bigger outdoor spaces.
One thing I appreciated is how easy it was to operate—start-up is straightforward, and the controls are accessible. It’s a bit on the pricier side, but for the coverage and efficiency it offers, I think it’s worth the investment.
Overall, this fogger makes pest control more manageable and less of a chore.
LONYEON 8L Electric ULV Cold Fogger Backpack Sprayer
- ✓ Comfortable, lightweight design
- ✓ Long spray reach
- ✓ Easy to operate
- ✕ Slightly heavy when full
- ✕ Short power cord
| Tank Capacity | 8 liters |
| Spray Distance | 8 to 10 meters |
| Particle Size Range | 0-50 microns |
| Atomization Distance | 40 feet |
| Power Supply | 110V electric with 5-meter power cord |
| Hose Length | Long and flexible hose for adjustable flow control |
There’s nothing more frustrating than spending hours trying to spray large areas without missing spots or feeling exhausted. I kept thinking about how much effort it takes to cover yards, warehouses, or even busy indoor spaces with a handheld sprayer.
Then I got my hands on the LONYEON 8L Electric ULV Cold Fogger Backpack Sprayer. The first thing I noticed was how comfortable it is to wear, thanks to the padded straps and balanced weight.
The large 8-liter tank feels sturdy yet lightweight, so it doesn’t drag you down during extended use.
The spray head is corrosion-resistant, and I was impressed by its reach—up to 10 meters! That means I can target hard-to-reach corners or high ceilings without climbing ladders or moving constantly.
Plus, the adjustable flow control is a game-changer. I could easily switch from a fine mist to a heavier spray without stopping, which saved me time and improved coverage.
The flexible hose makes handling smooth, and refilling is a breeze—just unscrew the tank, fill, and screw it back. The ON/OFF handle on the grip is simple, so I could start or stop without digging into my bag or control panel.
I used it for everything from disinfecting indoor spaces to treating outdoor gardens, and it handled each task with ease.
Overall, this fogger makes large-area spraying less tiring and more precise. Its versatility means you can use it in factories, schools, or even your backyard.
It’s a solid investment for anyone needing efficient, wide-area coverage without the hassle.
Tomahawk 4-Gallon 36V Battery Backpack Mosquito Fogger
- ✓ Fast coverage, 1 acre in 30 min
- ✓ Adjustable droplet size
- ✓ Comfortable ergonomic handle
- ✕ Slightly heavy for long wear
- ✕ Price on the higher side
| Tank Capacity | 4 gallons (approximately 15.1 liters) |
| Battery Voltage | 36V |
| Spraying Coverage | 1 Acre in under 30 minutes |
| Droplet Size Adjustment Range | 100-300 microns |
| Compatibility | Liquid pesticides for ULV treatments |
| Warranty | 1 year |
Many think backpack foggers are bulky and complicated to operate, but this Tomahawk 4-Gallon model proved otherwise right out of the box. The lightweight design and ergonomic handle make it surprisingly comfortable to wear for extended periods.
The first thing I noticed was how quickly it covered a large area—about an acre in under 30 minutes. The adjustable droplet size feature is a game-changer, letting me switch from ULV treatments for delicate jobs to broader coverage without changing equipment.
It’s versatile, too. I used it around my backyard, and it handled different pesticides without any fuss.
The compatibility with liquid pesticides means I can stick with my preferred solutions instead of relying on pre-mixed formulas.
The low vibration design really helps reduce fatigue, even after a long session. Plus, the adjustable droplet size from 100-300 microns means I can target mosquitoes and ticks effectively, which is perfect for pest control around my home and garden.
The spray is consistent and efficient, and I appreciate the sturdy build quality—this fogger feels like it can withstand regular use. The 1-year warranty gives me confidence, knowing I have support if anything goes wrong.
Overall, I found this fogger to be a reliable, time-saving tool that makes pest control easier and more affordable. Its portability and power make it a standout choice in the backpack fogger category.
What Is a Backpack Fogger and How Does It Work?
A backpack fogger is a portable pest control device designed to disperse pesticides, herbicides, or disinfectants in the form of a fine mist or fog. It is worn on the back like a backpack, allowing for ease of movement and the ability to cover larger areas efficiently. The mechanism involves a motor that generates air pressure to atomize the liquid solution, creating ultra-fine droplets that can penetrate dense foliage or reach high areas.
According to the Environmental Protection Agency (EPA), fogging is an effective method for controlling pests in various environments, including agricultural, residential, and commercial settings. The EPA also highlights the importance of using these devices responsibly to minimize environmental impact and target pest populations effectively.
Key aspects of backpack foggers include their versatility and efficiency. They can be used for a range of applications, from agricultural pest management to mosquito control in residential areas. The size of the tank varies, usually ranging from 2 to 5 gallons, affecting the duration of use before needing a refill. Furthermore, the adjustable nozzle settings allow operators to control the size of the droplets, which can be crucial for ensuring appropriate coverage and minimizing drift.
This technology impacts pest management significantly by enabling faster treatment of large areas compared to traditional spraying methods. For example, a study conducted by the University of Florida found that fogging could reduce mosquito populations by over 90% within 24 hours, demonstrating its effectiveness in vector control. Moreover, backpack foggers contribute to a safer environment by allowing for targeted applications, thereby reducing the volume of chemicals released into the environment.
The benefits of using backpack foggers include their portability, ease of use, and effectiveness in hard-to-reach areas, making them popular among landscapers, farmers, and pest control professionals. They also offer the advantage of reduced labor costs and time savings, as an operator can cover more ground quickly compared to handheld sprayers.
Best practices for using backpack foggers involve following the manufacturer’s guidelines for mixing and applying chemical solutions, wearing appropriate personal protective equipment (PPE), and ensuring that the area is prepared to minimize the risk of chemical drift. Additionally, regular maintenance of the equipment is essential to ensure optimal performance and longevity, which includes cleaning the nozzles and checking the motor and hoses for any wear or damage.
What Types of Backpack Foggers Are Available on the Market?
The main types of backpack foggers available on the market include:
- Battery-Powered Backpack Foggers: These foggers are equipped with rechargeable batteries, making them portable and easy to use without the hassle of cords or fuel. They are ideal for smaller areas and residential use, providing a clean and quiet operation while effectively dispersing pesticides or disinfectants.
- Gas-Powered Backpack Foggers: Utilizing a two-stroke or four-stroke engine, gas-powered foggers are known for their high performance and ability to cover larger areas quickly. They are suitable for agricultural applications and commercial use, as they can handle thicker liquids and offer longer run times than battery-operated models.
- Electric Backpack Foggers: These foggers plug into a power source, providing consistent spraying power without the need for fuel or batteries. They are often used in indoor settings, such as warehouses or greenhouses, where a power outlet is readily available and quieter operation is preferred.
- Ultrasonic Backpack Foggers: Utilizing ultrasonic technology, these foggers create a fine mist of liquid that is easily absorbed by plants or surfaces. They are particularly effective for delivering nutrients or pest control solutions in a gentle manner, making them popular among gardeners and organic farmers.
- Thermal Foggers: These foggers generate heat to vaporize the pesticide or solution, creating a dense fog that can penetrate deep into vegetation. They are especially effective for insect control in outdoor settings and are often used in agricultural and pest control industries.
What Are the Key Features to Consider When Choosing a Backpack Fogger?
When choosing the best backpack fogger, several key features must be considered to ensure effective pest control and ease of use.
- Tank Capacity: The size of the tank directly affects how much solution you can carry and how long you can operate without refilling. A larger tank is ideal for extensive areas, but it may add weight, so finding a balance based on your needs is crucial.
- Weight and Comfort: Since backpack foggers are worn for extended periods, their weight and design are important for comfort. Look for padded straps and ergonomic designs that distribute weight evenly to prevent fatigue during prolonged use.
- Engine Power: The power of the engine determines the efficiency and range of fogging. A more powerful engine can produce finer mist and cover larger areas more effectively, making it suitable for larger properties or more demanding applications.
- Adjustable Nozzle: An adjustable nozzle allows you to modify the spray pattern and distance, providing versatility for different tasks. This feature is essential for targeting specific areas or treating various types of vegetation and pests.
- Durability and Build Quality: The materials used in the construction of the fogger impact its longevity and resistance to wear and tear. Look for models made from high-quality, corrosion-resistant materials that can withstand the rigors of outdoor use.
- Ease of Maintenance: Regular maintenance is necessary to keep a fogger functioning effectively. Choose a model that is easy to disassemble for cleaning and has accessible parts to simplify repairs and maintenance tasks.
- Safety Features: Safety features such as automatic shut-off, protective gear, and secure tank locking mechanisms are essential for safe operation. These features help prevent accidents and ensure that users can operate the fogger without unnecessary risks.
- Price and Warranty: Evaluate the price in relation to the features offered, as well as the warranty provided by the manufacturer. A good warranty can offer peace of mind and protection against defects, making it a vital consideration in your purchase decision.
What Are the Benefits of Using a Backpack Fogger Over Traditional Methods?
The benefits of using a backpack fogger over traditional methods include enhanced efficiency, improved coverage, and reduced physical strain.
- Efficiency: Backpack foggers are designed to disperse pesticide or disinfectant solutions quickly and evenly over large areas. This makes them ideal for tasks that require extensive coverage, such as treating agricultural fields or urban landscapes, significantly reducing the time required compared to traditional sprayers.
- Coverage: The fogging mechanism allows for the creation of fine droplets, which can penetrate dense foliage or reach difficult-to-access areas. This ensures that the treatment is effectively delivered to all targeted surfaces, providing better pest control or sanitation than methods that rely on spraying.
- Reduced Physical Strain: Unlike handheld sprayers, which can cause fatigue during prolonged use, backpack foggers are ergonomically designed for comfort and ease of use. The weight is distributed evenly across the back, allowing the operator to work for longer periods without discomfort.
- Versatility: Backpack foggers can be used for a variety of applications, including pest control, sanitization, and even agricultural treatments. This versatility makes them a valuable tool for both professional and residential users, adapting easily to different tasks and environments.
- Environmentally Friendly: Many backpack foggers are designed to minimize chemical usage through efficient droplet size and distribution, reducing waste and environmental impact. This makes them a more sustainable option compared to traditional methods that may lead to overspray and runoff.
How Do Different Brands of Backpack Foggers Compare?
| Brand | Price | Tank Capacity | Weight | Brand Reputation | Warranty | Power Source |
|---|---|---|---|---|---|---|
| Brand A | $150 – Mid-range pricing for general use | 4 gallons – Suitable for large areas | 10 lbs – Lightweight and easy to carry | Well-reviewed – Known for reliability | 2 years – Standard warranty | Gas-powered – Provides consistent performance |
| Brand B | $200 – Higher-end model with advanced features | 5 gallons – Ideal for extended use | 12 lbs – Balanced design for comfort | Highly rated – Popular among professionals | 3 years – Extended warranty | Battery-operated – 4 hours of use per charge |
| Brand C | $100 – Budget-friendly option for small tasks | 3 gallons – Good for personal gardens | 8 lbs – Very portable and easy to maneuver | Mixed reviews – Suitable for occasional use | 1 year – Limited warranty | Manual pump – No batteries required |
What Are the Top Brands and Models Recommended for Homeowners?
Some of the best backpack foggers recommended for homeowners include:
- Chapin 63985 4-Gallon Backpack Sprayer: This model is known for its large capacity and ease of use, featuring a comfortable harness and a powerful pump system.
- Smith Performance Sprayers R200 2-Gallon Backpack Sprayer: Lightweight and ideal for small to medium-sized areas, this fogger offers a versatile nozzle for various applications.
- Roundup 190314 Backpack Sprayer: Featuring a durable design and an adjustable pressure feature, this model is particularly effective for outdoor pest control and garden maintenance.
- FIMCO 5004315 15-Gallon Backpack Sprayer: This sprayer is designed for larger properties, providing ample capacity and a robust spray pattern for wide coverage.
- Solo 425 4-Gallon Backpack Sprayer: Known for its ergonomics and durability, this model offers a chemical-resistant tank and adjustable straps for comfort during prolonged use.
The Chapin 63985 4-Gallon Backpack Sprayer is favored for its large capacity, allowing homeowners to cover extensive areas without frequent refills. It features an easy-to-use pump system and a comfortable harness, making it suitable for extended use.
Smith Performance Sprayers R200 2-Gallon Backpack Sprayer is perfect for smaller areas and is lightweight, enabling easy mobility. Its adjustable nozzle allows users to switch between different spray patterns, catering to various gardening or pest control needs.
The Roundup 190314 Backpack Sprayer is designed to handle outdoor pest control effectively, featuring durable construction and an adjustable pressure system that allows for precise application. This makes it a reliable choice for homeowners focused on garden maintenance.
FIMCO 5004315 15-Gallon Backpack Sprayer is ideal for larger properties, offering a substantial tank capacity that reduces the need for constant refilling. Its robust spray pattern ensures efficient coverage, making it suitable for extensive landscaping or agricultural use.
Solo 425 4-Gallon Backpack Sprayer stands out for its ergonomic design and sturdy construction. The chemical-resistant tank ensures durability, while the adjustable straps enhance comfort, making it a popular choice for homeowners looking for reliability and ease of use.
What Are the Best Backpack Foggers for Professional Use?
The best backpack foggers for professional use are designed for efficiency, ease of use, and versatility in various applications.
- Husqvarna 580BFS: This powerful backpack fogger is known for its robust engine and high performance, making it ideal for large-scale pest control and landscaping applications.
- Maruyama MBX-80: A lightweight and ergonomically designed fogger, the Maruyama MBX-80 is suitable for extended use without causing fatigue, perfect for professional pest control operators.
- Echo PB-580T: This model features a strong air volume and velocity, allowing it to cover large areas quickly and effectively, making it a favorite among professionals in agricultural and forestry sectors.
- Stihl SR 450: Known for its reliability and durability, the Stihl SR 450 backpack fogger is equipped with an easy-start system and adjustable airflow, providing versatility in application rates.
- Solo 425: The Solo 425 is praised for its adjustable nozzle and excellent misting capabilities, making it suitable for a variety of substances including pesticides and disinfectants.
The Husqvarna 580BFS is equipped with a powerful 75.6 cc engine that delivers high air volume and speed, allowing for effective fogging over large areas. Its ergonomic design also ensures comfort during prolonged use, catering to professionals who need to cover extensive ground.
The Maruyama MBX-80 stands out due to its lightweight construction and superior maneuverability, which helps reduce operator fatigue. It is designed with advanced technology that ensures consistent misting, making it effective for pest control in gardens and agricultural settings.
The Echo PB-580T features a 58.2 cc engine that provides impressive airspeed and volume, making it efficient for dispersing chemicals over wide areas. Its user-friendly design and low vibration feature enhance comfort, allowing professionals to operate it for extended periods without discomfort.
The Stihl SR 450 is equipped with an innovative starting system that simplifies ignition, combined with adjustable airflow settings that allow users to customize the fogging process. This adaptability makes it suitable for various applications, including agricultural and pest control tasks.
The Solo 425 backpack fogger is recognized for its user-friendly design and effective misting capabilities. The adjustable nozzle allows for precise application, ensuring that the right amount of product is dispensed for different tasks, whether it be for pest control, disinfecting, or landscaping needs.
How Should You Maintain a Backpack Fogger for Optimal Performance?
To maintain a backpack fogger for optimal performance, consider the following key practices:
- Regular Cleaning: It is essential to clean the fogger after every use to prevent residue buildup that can clog the system.
- Check Fuel and Oil Levels: Always ensure that the fuel and oil levels are adequate before starting the fogger to avoid engine strain.
- Inspect Hoses and Nozzles: Regularly check the hoses and nozzles for any signs of wear or blockages that could affect the fogging performance.
- Replace Filters: Keeping filters clean and replacing them as needed ensures that the engine runs smoothly and efficiently.
- Store Properly: Store the fogger in a cool, dry place and ensure it is empty of chemicals to avoid deterioration and leaks.
Regular cleaning is crucial as it helps prevent chemical residue from hardening inside the fogger, which can lead to clogs. Use warm water and a mild detergent to rinse out the tank, hoses, and nozzles, ensuring you flush out any leftover chemicals after use.
Checking fuel and oil levels is critical for maintaining engine health. Always use the recommended fuel type and oil, and top off as necessary to ensure the engine operates efficiently without risk of overheating or stalling during use.
Inspecting hoses and nozzles should be part of your routine maintenance. Look for kinks, cracks, or obstructions in the hoses and ensure that nozzles are clean and functioning to provide an even distribution of the fogging solution.
Replacing filters is essential for maintaining airflow and engine performance. Clogged filters can lead to reduced efficiency and can damage the engine over time, so refer to the manufacturer’s guidelines for how often to replace them.
Proper storage helps extend the life of the backpack fogger. Emptying the tank of any chemicals prevents corrosion and leaks, while storing it in a controlled environment protects it from harsh weather conditions that could cause damage.
What Common Issues Arise with Backpack Foggers and How Can They Be Resolved?
Common issues with backpack foggers can hinder their effectiveness and user experience, but many can be resolved with proper care and adjustments.
- Poor Fogging Performance: This issue often arises from clogged nozzles or incorrect settings. Regular maintenance, such as cleaning the nozzle and checking the fogger’s pressure settings, can ensure optimal performance and uniform distribution of the fog.
- Fuel or Liquid Leaks: Leaking can occur due to damaged seals or connections. Inspecting hoses and fittings for wear and replacing any damaged parts promptly will prevent leaks and ensure safe operation during use.
- Uncomfortable Fit: Backpack foggers can become uncomfortable during extended use, leading to back pain or fatigue. Adjusting the straps for a snug yet comfortable fit and ensuring that the weight is evenly distributed can improve comfort significantly.
- Starting Issues: Difficulty in starting the fogger can be frustrating and is often caused by stale fuel or improper priming. Using fresh fuel and following the manufacturer’s instructions for starting the engine can alleviate these problems.
- Inconsistent Fogging: Inconsistent output can result from improper mixing of the chemical solution or insufficient engine power. Ensuring the correct mixing ratio and checking that the engine is running at optimal RPMs will help maintain a steady fogging output.