Searching for the best cordless carpet stain removers in 2026? The top pick is the BISSELL Little Green Max Pet Portable Cleaner for its powerful cleaning and portability. The Shark StainForce Cordless Spot Cleaner stands out for quick stain removal, while the Vacmaster 600 Series offers impressive runtime. These tools help tackle spills without cords, but tradeoffs include battery life, cleaning power, and size. Keep reading for a detailed comparison that helps you find the ideal match for your needs.
Key Takeaways
- Top cordless stain removers balance cleaning power with battery life, often requiring tradeoffs between the two.
- Models with self-cleaning features reduce maintenance but tend to be more expensive and bulkier.
- Lightweight, compact designs excel for quick spot cleaning but may lack deep cleaning capacity.
- Reconditioned or renewed options can offer savings but may come with limited warranties or slightly reduced durability.
- Different user needs—like pet stain removal or auto detailing—are best served by specific features and accessories.
| BISSELL Little Green Max Pet Portable Carpet and Upholstery Deep Cleaner |  | Best Overall for Pet Stains and Odors | Power: 30% more powerful than competitors | Includes: Self-cleaning Tough Stain Tool, Pet Hair Removal Tool, 8 oz. trial formula | Technology: Triple Action cleaning with stain and odor removal | VIEW LATEST PRICE | See Our Full Breakdown |
| Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System for Carpets, Area Rugs, Upholstery, Stairs, HX101 (Renewed) |  | Best for Versatile Spot Cleaning on Multiple Surfaces | Weight: Under 3 lbs | Includes: StainForce Dual-Activated Solution, Reusable Spray Bottle, Charging Cable, Caddy, Cleaning Tools | VIEW LATEST PRICE | See Our Full Breakdown | |
| Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System for Carpets, Area Rugs, Upholstery, Stairs, HX105 (Renewed) |  | Best for Versatility and Compact Storage | Weight: Under 3 lbs | Includes: Stain Eliminator Tool, Crevice Tool, Caddy, Full-Size Solution, Reusable Spray Bottle, Charging Cable | VIEW LATEST PRICE | See Our Full Breakdown | |
| Shark StainForce Cordless Spot Cleaner |  | Best Compact for Car and Small Stains | Weight: Under 3 lbs | Solution Type: Dual-chamber refill with separate solutions | Included Attachments: Stain Eliminator Tool with reversible bristles, Crevice Tool, Grab & Go Caddy | VIEW LATEST PRICE | See Our Full Breakdown |
| BISSELL Little Green Mini Cordless Portable Carpet and Upholstery Deep Cleaner, Car/Auto Detailer, with HydroRinse Self-Cleaning Tool and 4″ Tough Stain Tool |  | Best for Car and Auto Detailing | Brand: Bissell | Model Number: 4015 | Item Type: Portable Carpet Cleaner | VIEW LATEST PRICE | See Our Full Breakdown |
| Shark StainForce Cordless Spot Cleaner with Dual-Activated Formula |  | Best Overall for Versatility and Effectiveness | Weight: Under 3 lbs | Solution Type: Dual-chamber refill with reusable spray head | Tools Included: Stain Eliminator Tool, Wide Stain Tool, Grab & Go Caddy | VIEW LATEST PRICE | See Our Full Breakdown |
| Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System |  | Best for Odor and Versatile Spot Cleaning | Color: Beige | Weight: Under 3 lbs | Solution Type: Dual-chamber refill with reusable spray head | VIEW LATEST PRICE | See Our Full Breakdown |
| Shark StainStriker Portable Carpet, Upholstery & Area Rug Cleaner |  | Best for Deep Cleaning and Odor Removal | Weight: Under 9 lbs | Tools Included: Crevice Tool, 3.5″ Stain Eliminator, 7″ XL Stain Eliminator, Pet Mess Extractor | Solution Capacity: 16oz Deep Clean Pro, 32oz OXY Multiplier | VIEW LATEST PRICE | See Our Full Breakdown |
| Portable Carpet & Upholstery Spot Cleaner Machine, 15Kpa Deep Cleaning for Rug, Pet, Couch, Stairs & Car |  | Best for Heavy-Duty Spot Cleaning with Self-Cleaning | Suction Power: 15Kpa | Motor Power: 500W | Tank Capacity: 1.5L clean / 0.8L dirty | VIEW LATEST PRICE | See Our Full Breakdown |
| Vacmaster 600 Series 24V Cordless Portable Carpet & Upholstery Spot Cleaner Machine, DSCC2401 |  | Best for Pet Stains and Deep Spot Cleaning | Model Number: DSCC2401 0101 | Battery: 24V 2.0Ah | Suction Power: 16Kpa | VIEW LATEST PRICE | See Our Full Breakdown |
More Details on Our Top Picks
BISSELL Little Green Max Pet Portable Carpet and Upholstery Deep Cleaner
This model stands out for its superior suction power—30% more effective than many competitors like the Shark StainForce HX105—making it a top choice for pet owners battling tough stains and odors. Its lightweight, portable design and self-cleaning tool make quick work of small, soft surfaces, especially when compared to bulkier options like the BISSELL Little Green Mini. However, it’s limited to small-scale cleaning and needs specific formulas to work best, which can be inconvenient for larger messes. The dual tanks simplify operation, and its support for pet rescue charities adds a feel-good factor. The main tradeoff is its focus on soft surfaces, so it’s less suitable for heavy-duty cleaning or large areas.
Pros:- Effective pet stain and odor removal
- Lightweight and easy to maneuver
- Self-cleaning tool simplifies maintenance
Cons:- Limited to small or soft surfaces
- Requires specific formulas for optimal results
Best for: Pet owners needing efficient, portable solutions for small soft surface stains and odors
Not ideal for: Homeowners with large carpeted areas or heavy-duty cleaning needs, due to its limited size and power
- Power:30% more powerful than competitors
- Includes:Self-cleaning Tough Stain Tool, Pet Hair Removal Tool, 8 oz. trial formula
- Technology:Triple Action cleaning with stain and odor removal
- Design:Lightweight, portable, with longer hose and cord
Bottom line: This cleaner is perfect for pet owners wanting a portable, effective solution for small stains and odors on soft surfaces.
Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System for Carpets, Area Rugs, Upholstery, Stairs, HX101 (Renewed)
Compared with the BISSELL Little Green Max Pet, the Shark StainForce HX101 excels in versatility—its cordless design and included accessories make it ideal for quick spot treatments on carpets, upholstery, stairs, and even car interiors. Its lightweight build under 3 lbs allows for easy maneuvering around tight spaces, but it’s primarily a spot cleaner rather than a deep cleaning device, which limits its use for larger areas. The powerful stain-fighting formula and odor elimination make it effective on stubborn messes, yet battery life could be better for extended use. It’s best suited for those who need a portable, quick solution for occasional stains rather than regular deep cleaning.
Pros:- Cordless and lightweight for easy handling
- Effective on a variety of surfaces including upholstery and stairs
- Powerful stain and odor removal capabilities
Cons:- Limited battery life for extensive cleaning
- Designed mainly for spot cleaning, not large areas
Best for: Homeowners who need a quick, portable stain and odor remover for small areas and occasional use
Not ideal for: Users seeking a device for deep cleaning large carpeted spaces or heavy-duty tasks, due to its size and battery limitations
- Weight:Under 3 lbs
- Includes:StainForce Dual-Activated Solution, Reusable Spray Bottle, Charging Cable, Caddy, Cleaning Tools
Bottom line: This pick is ideal for those needing a portable, quick-response tool for small stains and odors across multiple surfaces.
Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System for Carpets, Area Rugs, Upholstery, Stairs, HX105 (Renewed)
This version of the Shark StainForce HX105 shares many features with the HX101 but adds a compact design and included caddy for easier storage and transport. It remains effective at removing stubborn stains and odors on various surfaces, making it a versatile choice for everyday messes. Compared to the larger, more involved carpet cleaners like the BISSELL Little Green Max Pet, it’s more suited for quick spot treatments rather than deep cleaning. Its battery life is similar, requiring recharges after several uses. This device is a solid option for users who want a lightweight, multi-surface stain remover that can be stored conveniently between uses.
Pros:- Compact with included storage caddy
- Effective at removing tough stains and odors
- Lightweight and easy to maneuver
Cons:- Limited battery capacity for extended cleaning
- Not designed for large-area cleaning tasks
Best for: Families or individuals who want an all-around portable stain remover for small to medium messes
Not ideal for: Those needing a deep-cleaning machine for large or heavily soiled carpets, due to its limited capacity and battery life
- Weight:Under 3 lbs
- Includes:Stain Eliminator Tool, Crevice Tool, Caddy, Full-Size Solution, Reusable Spray Bottle, Charging Cable
Bottom line: This cleaner suits users seeking a versatile, easy-to-store device for quick stain removal on multiple surfaces.
Shark StainForce Cordless Spot Cleaner
Compared to the larger Shark models, this compact StainForce excels at removing small stains and spills from cars, upholstery, and outdoor furniture. Its dual-activated formulas and reversible bristle tool provide effective stain removal without the bulk, making it ideal for quick cleanups. However, its small size limits its ability to handle larger or embedded stains, and battery life may be insufficient for multiple or prolonged cleaning sessions. It’s best suited for users who need a portable, no-fuss device for occasional, localized messes, especially in vehicles or outdoor settings.
Pros:- Compact and lightweight for portability
- Dual-activated formulas activate on contact
- Versatile for multiple surfaces including cars
Cons:- Limited to small stains and spills
- Requires frequent refills and recharging
Best for: Car owners and outdoor furniture users who need a portable stain remover for small spills and pet messes
Not ideal for: People looking to clean large or heavily soiled areas regularly, due to its size and limited battery life
- Weight:Under 3 lbs
- Solution Type:Dual-chamber refill with separate solutions
- Included Attachments:Stain Eliminator Tool with reversible bristles, Crevice Tool, Grab & Go Caddy
- Power Source:Rechargeable battery
Bottom line: This device is a smart choice for quick, targeted stain removal in vehicles and small outdoor spaces.
BISSELL Little Green Mini Cordless Portable Carpet and Upholstery Deep Cleaner, Car/Auto Detailer, with HydroRinse Self-Cleaning Tool and 4″ Tough Stain Tool
Compared with the larger BISSELL Little Green Max Pet, this mini version emphasizes portability and precision, making it ideal for detailed cleaning in vehicles, upholstery, and small carpets. Its 20-minute battery life limits extended sessions, but the included HydroRinse self-cleaning tool and narrow 4-inch stain tool make it highly effective for targeted tasks. Customer reviews cite some durability concerns, which is a consideration for those seeking a long-term investment. This device excels for users who need a lightweight, specialized tool for auto or furniture detailing, but it’s less suited for extensive household cleaning.
Pros:- Lightweight and portable for vehicle use
- Includes specialized tools for tough stains
- Self-cleaning feature simplifies maintenance
Cons:- Limited to 20 minutes of cordless operation
- Durability concerns reported by some users
Best for: Auto detailers and pet owners needing a portable, focused cleaner for small spaces and upholstery
Not ideal for: Users looking for a machine capable of deep cleaning large areas or heavy stains regularly, due to its short battery life and limited capacity
- Brand:Bissell
- Model Number:4015
- Item Type:Portable Carpet Cleaner
- Included Components:Upholstery tool
- Weight:7 lbs
Bottom line: This cleaner is best for detailed, targeted cleaning in cars and furniture, especially for users prioritizing portability.
Shark StainForce Cordless Spot Cleaner with Dual-Activated Formula
This model stands out for combining lightweight portability with dual-activated solutions that fight stains on multiple surfaces, including outdoor furniture, unlike the Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System, which emphasizes odor removal and versatility. Its dual solutions activate on contact, providing a quick and powerful response for small stains, but the handheld design limits its capacity for larger messes and extended cleaning. The inclusion of multiple tools makes it highly adaptable, yet it requires frequent refills due to its small solution reservoir, and battery life may fall short during bigger jobs. Compared to larger, more robust cleaners, this pick excels in quick, targeted stain removal but isn’t suited for heavy-duty or continuous use.
Pros:- Lightweight and cordless for easy handling
- Dual solutions activate instantly for powerful stain removal
- Includes multiple targeted tools for soft and hard surfaces
Cons:- Limited to small stains and quick cleanups
- Battery life may be insufficient for larger tasks
- Refilling solutions can interrupt ongoing cleaning
Best for: Homeowners needing a portable, effective spot cleaner for occasional use on furniture, outdoor, and indoor surfaces.
Not ideal for: People with large or deep stains expecting to clean extensive areas, as its handheld design limits capacity and runtime.
- Weight:Under 3 lbs
- Solution Type:Dual-chamber refill with reusable spray head
- Tools Included:Stain Eliminator Tool, Wide Stain Tool, Grab & Go Caddy
- Power Source:Cordless
- Activation:Dual-activated formula with OXY power
Bottom line: This cleaner is best for users who want quick, targeted stain removal with minimal fuss and portability.
Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System
Compared with the Shark StainForce Cordless Spot Cleaner, this model prioritizes odor control alongside stain removal, making it ideal for households with pets. Its cordless, lightweight design allows for easy maneuvering around furniture and vehicles, but its compact size limits it to small stains and quick touch-ups. The dual solutions activate on contact, providing effective stain lifting, yet it requires recharging and may struggle with stubborn, deep-set stains. The included accessories, like the reversible bristle tool, add versatility, but the small size means frequent recharges for larger or multiple messes. Overall, this option is perfect for quick, versatile cleaning in small areas but less suited for intensive, deep cleaning tasks.
Pros:- Lightweight and cordless for easy handling
- Dual solutions activate instantly for stain and odor control
- Includes versatile accessories for multiple surfaces
Cons:- Limited to small stains and quick cleanups
- Requires recharging between uses
- Effectiveness varies with very deep stains
Best for: Pet owners or those needing a portable stain and odor solution for frequent quick cleanups around the home or car.
Not ideal for: Users dealing with large or very stubborn stains requiring prolonged, heavy-duty cleaning, as the battery life and size can be limiting.
- Color:Beige
- Weight:Under 3 lbs
- Solution Type:Dual-chamber refill with reusable spray head
- Power:Cordless, rechargeable
- Included Accessories:Stain Eliminator Tool, reversible bristles, spray bottle, charging cable
Bottom line: This cleaner is ideal for quick, versatile spot cleaning and odor control in small areas or on-the-go situations.
Shark StainStriker Portable Carpet, Upholstery & Area Rug Cleaner
This model offers more thorough cleaning with four specialized tools and powerful OXY solutions, making it a step up from smaller handhelds like the Shark StainForce Cordless Spot Cleaner. Its larger weight under 9 pounds is justified by its deep cleaning capabilities, but it’s less portable for quick jobs compared to smaller options. The 16oz and 32oz solution capacities mean less frequent refills during intensive cleaning, though it requires specific Shark solutions for optimal results, which adds to ongoing costs. It’s best suited for homeowners with frequent deep stains or odors, especially on carpets and upholstery, but less so for casual, quick touch-ups.
Pros:- Effective at removing tough stains and odors
- Includes multiple specialized tools for different surfaces
- Larger solution capacity reduces refills
Cons:- Heavier and less portable than smaller handhelds
- Requires specific Shark solutions for best results
- Limited to smaller areas due to solution capacity
Best for: Homeowners seeking a portable, deep-cleaning device for carpets, rugs, and upholstery with odor elimination needs.
Not ideal for: Those who prefer very lightweight, ultra-portable cleaners for quick, light cleaning tasks, as it’s heavier and more suited to thorough jobs.
- Weight:Under 9 lbs
- Tools Included:Crevice Tool, 3.5″ Stain Eliminator, 7″ XL Stain Eliminator, Pet Mess Extractor
- Solution Capacity:16oz Deep Clean Pro, 32oz OXY Multiplier
- Power Source:Cordless, battery operated
- Features:Portable, multiple tools, deep cleaning
Bottom line: This cleaner is well-suited for users who prioritize deep cleaning and odor removal over portability for occasional larger jobs.
Portable Carpet & Upholstery Spot Cleaner Machine, 15Kpa Deep Cleaning for Rug, Pet, Couch, Stairs & Car
Compared to smaller handhelds like the Shark StainForce, this model offers a more powerful 15Kpa suction and self-cleaning system, making it suitable for stubborn stains on larger surfaces. Its dual-tank design helps separate clean and dirty water, enabling more effective cleaning sessions, especially on carpets, upholstery, and stairs. The inclusion of multiple brush heads and a flexible hose increases its versatility, but its size and weight make it less convenient for quick, one-off spot cleanups. The need for careful tilting for maximum suction and the limited capacity mean it’s better suited for targeted, deep cleaning rather than frequent, light use. It’s ideal for users who need a more substantial portable cleaner with self-maintenance features.
Pros:- Powerful 15Kpa suction for tough stains
- Self-cleaning system simplifies maintenance
- Includes multiple brush heads and a flexible hose
Cons:- Heavier and less portable than handheld options
- Requires careful tilting for optimal suction
- May need multiple passes for stubborn stains
Best for: Homeowners or pet owners needing a more robust, deep cleaning solution for stubborn stains and odors in larger areas or on stairs and upholstery.
Not ideal for: Users who need a lightweight, quick-use device for occasional, light cleaning, as this model is heavier and more involved to operate.
- Suction Power:15Kpa
- Motor Power:500W
- Tank Capacity:1.5L clean / 0.8L dirty
- Hose Length:4.26ft
- Included Components:2 Brush Heads
Bottom line: This cleaner is perfect for those seeking a deep, heavy-duty spot cleaning tool with self-maintenance features for larger or stubborn stains.
Vacmaster 600 Series 24V Cordless Portable Carpet & Upholstery Spot Cleaner Machine, DSCC2401
Compared with the Shark StainForce Cordless Portable Spot, Stain, & Odor Remover System, the Vacmaster DSCC2401 emphasizes more power with a 16Kpa suction and a larger battery, making it suitable for more demanding pet messes and deep stains. Its cordless design allows for flexible use in hard-to-reach areas, but the battery life may limit extended cleaning sessions, especially when tackling multiple or large stains. The included versatile tools and oxy solution support effective stain and odor removal, but the trial-sized solution means ongoing supplies will be needed for sustained use. This model excels when users need a portable, more powerful tool for stubborn pet stains, though it might fall short for continuous, large-area cleaning.
Pros:- Cordless and highly portable for flexible use
- Effective stain and odor removal with included oxy solution
- Versatile tools for different surfaces and tight spaces
Cons:- Limited battery life during extended cleaning
- Trial size solutions require additional purchases
- Suction power may be insufficient for very deep or heavy stains
Best for: Pet owners or users needing a portable, high-power stain remover for persistent pet messes and deep stains in various locations.
Not ideal for: People seeking a lightweight, long-lasting cleaning device for frequent, small touch-ups, as its battery life and solution size are limiting factors.
- Model Number:DSCC2401 0101
- Battery:24V 2.0Ah
- Suction Power:16Kpa
- Included Components:2-in-1 stain tool, wide path tool, hose cleaning tool, 8 oz. cleaning formula, oxy solution, battery & charger
- Item Type:Cordless Carpet & Upholstery Spot Cleaner
Bottom line: This cleaner is best suited for pet owners or those needing a portable, powerful stain remover for stubborn, localized messes in various settings.
How We Picked
These products were selected based on their ability to effectively remove stains from carpets and upholstery without the need for a cord. Evaluation criteria included cleaning performance, battery life, usability, size and weight, maintenance features, and overall value. We prioritized models that cater to different user needs, from quick touch-ups to deep cleaning, ensuring a comprehensive overview. Rankings reflect a balance of these factors, aiming to help buyers find the best cordless stain remover for their specific situations.Factors to Consider When Choosing Cordless Carpet Stain Removers
Choosing the right cordless carpet stain remover involves considering several key factors beyond just cleaning ability. Battery life determines how many stains you can treat before recharging, so assess your typical cleaning sessions. Portability and weight are critical if you’ll be moving around frequently or cleaning stairs. Compatibility with different surfaces and stain types ensures versatility, especially for pet stains or auto detailing. Additionally, features like self-cleaning systems or specialized brushes can streamline maintenance and improve results. Understanding these broader considerations helps avoid common pitfalls like underestimating battery needs or overpaying for unnecessary features.Battery Life and Runtime
Battery life is a defining factor for cordless stain removers, dictating how many stains you can address in one session. Short runtimes can be frustrating if you have larger or multiple stains, so opt for models with at least 15-20 minutes of continuous use. Consider recharge times as well—fast-charging batteries reduce downtime. If you plan to clean multiple rooms or large areas frequently, investing in a model with extended battery life ensures smoother operation without frequent recharges. Keep in mind that higher capacity batteries often add weight and cost, so weigh your priorities accordingly.
Cleaning Power and Effectiveness
Effective stain removal depends on both the suction power and the cleaning formulas used. While cordless models typically don’t match corded heavy-duty cleaners, look for units with strong suction and adjustable settings for different stain types. Some models include dual-activated formulas or specialized brushes that boost cleaning outcomes, especially on pet messes or deep-set stains. Remember, a more powerful cleaner may consume more battery or be bulkier, so find a balance that aligns with your most common cleaning tasks. Test results, user reviews, and brand reputation can also guide your expectations for real-world effectiveness.
Size, Weight, and Portability
Since cordless cleaners are meant for quick, on-the-spot cleaning, their size and weight matter significantly. Lightweight models under 4 pounds are ideal for frequent use on stairs, furniture, or auto interiors. However, smaller units may have limited capacity or battery life, which could necessitate more frequent recharges. Conversely, larger, heavier models might offer longer runtime and better cleaning performance but can be cumbersome to maneuver. Consider your typical cleaning environment and choose a size that offers a comfortable balance between power and portability.
Ease of Maintenance and Accessories
Maintenance features like self-cleaning systems or easy-to-remove tanks can save time and prolong the lifespan of your device. Accessories like different brushes, nozzles, or formulas expand versatility, especially if you tackle various stains or surfaces. Some models include auto-shutoff or indicator lights for battery and tank status, helping avoid interruptions. Be cautious about models with complex parts that might be difficult to clean or replace; simplicity often leads to better durability. Investing in a unit with thoughtful maintenance features can make regular cleaning less of a chore.
Price and Value
Pricing varies widely, from budget-friendly options to premium models with advanced features. While cheaper models may do a decent job for light stains, they often lack durability or sufficient power for tougher messes. Premium models tend to include extras like longer battery life, self-cleaning, or specialized tools, which justify higher costs if those features match your needs. Consider your typical cleaning frequency, stain severity, and budget to determine the best value. Sometimes, paying more upfront results in a more reliable, long-lasting device, especially if you regularly deal with pet stains or auto interiors.
Frequently Asked Questions
Can cordless carpet stain removers handle deep-set stains?
Cordless stain removers are generally designed for quick touch-ups and surface stains, but some higher-end models with stronger suction and specialized brushes can tackle deeper stains to a degree. They may not replace full-sized, corded deep-cleaning machines, especially for heavily embedded dirt. For frequent deep cleaning, these units work best as supplements rather than primary tools. Selecting a model with adjustable settings and powerful suction increases the likelihood of addressing stubborn stains more effectively.
How long does the battery typically last on these devices?
Battery life varies among models, with most offering between 15 to 30 minutes of continuous use on a full charge. Shorter runtimes can be limiting if you have multiple stains or larger areas, so consider a device with a quick recharge feature or extra batteries. Remember, higher-capacity batteries tend to add weight and cost, so choose a balance based on your cleaning frequency. Reading user reviews can also provide insights into real-world battery performance, helping you pick a model that meets your needs.
Are cordless stain removers suitable for auto detailing?
Yes, many cordless carpet stain removers are versatile enough to be used on auto interiors, especially for upholstery and carpets. Their portability makes them convenient for vehicle cleaning, where cords can be restrictive. Look for models with appropriate attachments like small brushes or nozzles designed for tight spaces. Keep in mind that auto detailing often requires frequent, quick cleanups, so lightweight, easy-to-maneuver models tend to work best. Also, consider whether the device’s cleaning power and battery life match the scope of your auto cleaning needs.
What’s the best way to maintain a cordless stain remover?
Regular maintenance involves emptying the collection tank after each use and cleaning the brushes and nozzles to prevent residue buildup. Many models include self-cleaning or rinse systems, which simplify this process. Check the manufacturer’s instructions for proper cleaning solutions and avoid using harsh chemicals that could damage components. Proper storage, such as keeping the device charged and in a dry place, extends its lifespan. Routine maintenance not only keeps the device performing well but also helps avoid odors or mold from developing inside the unit.
