Breathe Naturally - October 31, 2023
The Effectiveness of Washable vs. Disposable Air Purifier Filters
Key Takeaways:
- Disposable filters like HEPA and activated carbon have superior particle capture but higher replacement costs.
- Washable filters can be cleaned and reused, saving money long-term, but have reduced filtration performance.
- Washable filters may need cleaning weekly or more for optimal performance. Disposables only need replacement every 6-12 months typically.
- Hybrid filters combine a disposable HEPA filter with a washable prefilter to get the best of both options.
- Consider airflow resistance, filter media, and construction for washable filters to maintain filtration and durability with cleaning.
- Take care not to damage disposable media when washing filters or drying after cleaning.
When purchasing an air purifier, the ongoing cost of filters and how often they need replacement is an important consideration. Air purifiers use different filter types depending on the technology and contaminants they target. Broadly, filters fall into two categories: disposable and washable. Disposable types like HEPA and activated carbon excel at particle removal but need periodic replacement.
Washable filters save on replacement costs but can't match the filtration performance of disposables. Understanding the pros and cons helps determine the best choice for your needs and budget.
Why Disposable Filters Have Superior Particle Removal
Disposable filters used in air purifiers include HEPA, activated carbon, and specialized blends. As air passes through the dense arrangement of microscopic fibers and pores, particulate matter gets trapped within. This removes airborne particles like pollen, mold, pet dander, dust mites, bacteria, pollution particles, and more. The precise micron-grade pores of HEPA filters exclude particles as small as 0.3 microns with 99.97% efficiency. Activated carbon adsorbs gases, fumes and odors.
The tradeoff for this superior trapping capability is that, over time, particles will accumulate in the filter and begin to clog the pathways through. This increases airflow resistance and decreases performance. Once particulate filters appear dirty or pressure gauges indicate restricted airflow, replacement is required to maintain purification levels. For most models, this is around 6-12 months for typical use.
Though replacing disposable filters creates waste and ongoing costs, even high-quality washable filters can’t match the particle capture of new HEPA and activated carbon media. Oily particulates and fine bioaerosols are especially difficult to fully eliminate from washable filters. So disposables provide the best filtration, albeit temporarily before needing a change.
When Washable Air Filters Offer Cost Savings
Washable reusable air filters provide a more eco-friendly and budget-friendly option. Rather than being thrown out, washable filters can be cleaned periodically by soaking, rinsing and drying. This restores airflow and extends usability for months or years before a replacement is required. With some maintenance effort, washable filters lead to significant long-term savings from not having to buy replacements.
However, washable air filters made of polyester, foam or fiberglass mesh can’t achieve the same level of filtration compared to HEPA and activated carbon media. The pores and gaps are simply larger, allowing more particles like dust mites and pollen through. Performance degrades further as contaminants accumulate between washes.Washable air filters work adequately for prefiltering large particulates like dust and pet hair. But users with allergies may still react to the smaller particles not captured. Washing also inevitably damages the filter material over time. So washable filters require more frequent cleaning and have shorter lifespans than quality disposables.
Getting the Best of Both: Hybrid Disposable and Washable Filters
To balance cost savings and effective particle removal, some air purifiers use a hybrid filter configuration. This approach combines a disposable True HEPA filter for particle capture along with a washable prefilter. The washable outer layer traps larger debris like hair and lint to extend the HEPA filter’s lifespan. Meanwhile, the inner HEPA filter removes fine particulates the prefilter misses.
Other hybrid designs utilize a disposable HEPA/activated carbon cartridge combined with a washable prefilter sleeve or cassette surrounding it. This kind of construction allows periodically rinsing just the outer prefilter to maintain airflow while the inner cartridge only needs infrequent replacement. These hybrid options give cleaner air for allergy sufferers than washable media alone, while lasting longer than an exclusively disposable setup.
Considerations for Effective Washable Filter Performance
Washable air filters still require care and maintenance to work optimally. Here are factors to consider:
- Check the material composition. Polyester and PTFE stand up to washing better than paper or fiberglass.
- Densely woven mesh traps more particles but requires vigorous rinsing to avoid clogging.
- Avoid cheap filters prone to mold, mildew, and tearing. Spending more initially saves long-term.
- Wash filters in the bathtub using mild detergent and warm water to thoroughly dislodge particulates.
- Rinse well with clean water to prevent soap residue impeding airflow.
- Shake off excess water and air dry completely before reinstalling to prevent mold growth. Drying may take 24 hours or more.
- Clean washable filters at least monthly based on usage. More frequently during allergy season or for pet owners.
- Inspect for tears, gaps, and integrity issues with each washing. Replace if filters become damaged or porous.
For optimal performance, washable filters should be cleaned weekly or biweekly depending on environmental factors. Infrequent cleaning allows more particulate buildup in between, reducing effectiveness. Proper care also prevents odors from dirty filters being recirculated into indoor air. With routine maintenance, high quality washable air filters can offer reliable filtration at a fraction of the cost of endless disposable filter replacements.