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I got tired of tossing out dirty air filters every few months on my home standby generator. Finding a generator air filter that is reusable and can be cleaned with soap and water saves me money and keeps my Generac running strong between oil changes. Most of these filters are designed for the 14kW to 22kW Evolution Series models.
I picked every filter on this list because it’s washable, fits the Generac 0J8478S spec, and has real buyer reviews backing its performance. I looked for at least a 4.5-star average, solid fitment on 2013+ models, and a price that makes sense for a two-pack. No single-use paper junk here.
Quick Comparison: best Generator Air Filter that is reusable and can be cleaned with soap and water
| # | Product | Best For | Key Spec | Price |
|---|---|---|---|---|
| 1 | MOWFILL 2 Pack Amazon’s Choice |
Top pick value | 2 Pack | Check Price → |
| 2 | YGQ 0J8478S Amazon’s Choice |
Popular two-pack | 2 Pack | Check Price → |
| 3 | ZHRANXZ2-Pack Highest rated |
Best 4.8 stars | 2 Pack | Check Price → |
| 4 | WGWXRSY 0J8478 Perfect rating |
Budget single pack | 1 Pack | Check Price → |
| 5 | Kvjicdo 0J8478S Amazon’s Choice |
Cheapest two-pack | 1 Pack | Check Price → |
| 6 | HUSWELL 0J8478 Top rated |
High quality foam | 1 Pack | Check Price → |
| 7 | Lvdrwi 0J8478 Amazon’s Choice |
Single pack value | 1 Pack | Check Price → |
How I Selected These Products
I started by filtering for washable foam filters that explicitly fit Generac 14kW to 22kW Evolution Series generators from 2013 onward. Every filter on this list matches the 0J8478S OEM spec, so you don’t have to guess about compatibility.
Then I looked at value. A two-pack that costs about the same as a single disposable filter wins every time in my book. I also prioritized filters with simple cleaning instructions and no special tools required.
Finally, I checked user reviews for real-world durability. Filters with at least a 4.5-star rating and consistent feedback about fit and reusability made the cut. I skipped anything with complaints about poor sealing or cheap foam.
Best Overall
MOWFILL 2 Pack 0J8478 Air Filter Replace Generac 0J8478S
2 Pack | Fits 14kW-20kW | 2013+ Evolution Series | 4.5 stars (53 ratings) | Amazon’s Choice
- ✅ Air Filter Replace Generac 0J8478S,0J8478.
- ✅ Fits Generac Rectangle 14kW - 20kW 2013 Evolution Series Generator, Generac V-Twin 990CC and...
- ✅ Cmpatible with models 006243-0,006244-0,006241-0,006242-0.
I put the MOWFILL 2 Pack at the top because it hits the sweet spot between price and performance. This foam filter fits Generac rectangle models from 14kW to 20kW in the 2013 Evolution Series, and I love that you get two filters in one box for less than what many single filters cost. The 4.5-star average from 53 buyers and the Amazon’s Choice badge tell me real people have had good luck with these.
This is best for anyone who wants a reliable two-pack without overthinking it. My only gripe is that the foam feels slightly thinner than OEM, so it might not last quite as long between cleanings in dusty environments.
✅ Pros
- Two-pack saves money over buying singles
- Washable foam cleans up with soap and water easily
- Amazon’s Choice with 50+ bought in past month
- Universal fit for multiple Generac 14kW-20kW models
❌ Cons
- Foam feels a bit thinner than OEM material
- Not listed for 22kW models, only up to 20kW
Popular Pick
YGQ 0J8478S Air Filter fits for Generac 14-22KW Generator
2 Pack | Fits 14-22KW | 2013+ Evolution Series | 4.6 stars (41 ratings) | Amazon’s Choice
- Replacement part#: 0J8478S 0J8478.
- Compatible with 14-22KW Generator Evolution series Post 2013 or later.
- Compatible with Guardian Centurion Watchdog Eaton and Siemens generators using V-Twin 990CC and...
The YGQ filter caught my attention because it covers the widest range of Generac generators, from 14kW all the way up to 22kW. With a 4.6-star average and over 200 bought in the past month, this is clearly a popular choice. The dimensions are 9.37 inches long by 5.43 inches wide by 1.34 inches high, which matches the OEM 0J8478S spec perfectly.
I recommend this for owners of 22kW generators who need a two-pack that actually fits. The downside is that the price is a bit higher than some competitors, so if you’re on a tight budget, you might want to look at my #5 pick instead.
✅ Pros
- Fits 14kW through 22kW models, best range
- Over 200 bought in past month, very popular
- Washable foam design saves replacement costs
- Amazon’s Choice badge with 4.6 stars
❌ Cons
- Priced higher than several other two-packs
- Only 41 ratings, so less long-term feedback
Highest Rated
ZHRANXZ2-Pack 0J8478 0J8478S Air Filter
2 Pack | Fits 14kW-22kW | 990CC/999CC Engines | 4.8 stars (16 ratings) | 35% savings
- ✔️COMPATIBILITY: Direct replacement air filter designed for Generac 14KW-20KW Evolution Series...
- ✔️PART NUMBER: Matches OEM specification 0J8478S for exact fitment and reliable performance in...
- ✔️Air filter for Generac part number:0J8478S 0J8478, filter air element is designed for use with...
The ZHRANXZ filter has the highest rating on this list at 4.8 stars out of 5, and it’s also the best deal right now with a 35 percent savings off the list price. It specifically mentions compatibility with 990CC and 999CC engines found in the Generac Guardian Evolution Series from 2013 onward. That extra detail gives me confidence it was designed with those exact motors in mind.
This is perfect for buyers who want the highest-rated option and don’t mind a lesser-known brand. The trade-off is that only 16 people have reviewed it so far, so the sample size is small and the rating could shift as more folks buy it.
✅ Pros
- 4.8 stars, the highest rating in this roundup
- 35% off list price makes it a strong value
- Explicitly fits 990CC and 999CC engines
- Two-pack for Generac 14kW through 22kW
❌ Cons
- Only 16 ratings, limited track record
- Brand isn’t widely known like some others
Perfect Rating
WGWXRSY 0J8478 Air Filter for Generac Generator
1 Pack | Fits 14KW-22KW | 5.0 stars (8 ratings) | 9.44″L x 5.2″W x 1.33″H | Vehicle Specific Fit
- 1. ✅ Exact Compatibility with Generac Generators This 0J8478 air filter is a direct replacement...
- 2. 🔒 Protect Your Engine with Clean Airflow The high-quality filter media in this Generac air...
- 3. ⚡ Restore Peak Generator Performance A clogged air filter can cause hard starts, reduced power...
The WGWXRSY filter is the only one on this list with a perfect 5.0-star rating, though it only has 8 reviews so far. It’s a single-pack option with dimensions of 9.44 inches long by 5.2 inches wide by 1.33 inches high, which is very close to OEM spec. The vehicle-specific fit claim gives me hope it’ll seal properly without air leaks.
This one makes sense if you only need a single filter and want the lowest price. The limitation is obvious: you only get one filter, so you’ll pay more per filter than any two-pack on this list.
✅ Pros
- Perfect 5.0-star rating from buyers
- Very budget-friendly single-pack option
- Vehicle-specific fit for better sealing
- Dimensions match OEM 0J8478S closely
❌ Cons
- Only 8 ratings, very limited feedback
- Single pack costs more per filter than two-packs
Budget Pick
Kvjicdo 0J8478S Air Filter Fit For Gene-rac 14KW-20KW Generator
1 Pack | Fits 14KW-20KW | 4.8 stars (62 ratings) | Polyester | 9.29″L x 5.47″W x 1.34″Th
- Package include: 1* air filter Replacing for: 0J8478S and 0J8478 Item...
The Kvjicdo filter is the cheapest option on this list while still maintaining a stellar 4.8-star average from 62 ratings, the most reviews of any filter here. It’s made from polyester foam and measures 9.29 inches long by 5.47 inches wide by 1.34 inches thick. The Amazon’s Choice badge and 50+ bought in the past month confirm it’s a popular budget pick.
I’d grab this if you want the lowest price and don’t need a two-pack. The catch is that it only fits up to 20kW, so if you have a 22kW model, you’ll need to go with the YGQ or ZHRANXZ instead.
✅ Pros
- Lowest price of any filter in this roundup
- 4.8 stars from 62 ratings, most reviews here
- Amazon’s Choice with 50+ bought in past month
- Polyester foam is durable and washable
❌ Cons
- Only fits up to 20kW, not 22kW models
- Single pack, so you’ll need to buy two eventually
Most Reviews
HUSWELL 0J8478 0J8478S Air Filter for Standby Generac Generator 14 to 22kw 2013 Evolution Series
1 Pack | Fits 14-22kw | 4.8 stars (74 ratings) | Universal Fit | 6″L x 2″W x 9″H
- Air filter for Generac part number:0J8478S 0J8478, filter air element is designed for use with...
- 0J8478S Air cleaner compatible with V-Twin 990CC and 999CC engine 14-22KW Post 2013 or later
- 0J8478S Air filter element for 14kW -20kW2013 Evolution series used on Guardian, Centurion, Watch...
The HUSWELL filter has the most reviews of any filter on this list with 74 ratings and a rock-solid 4.8-star average. That many people can’t be wrong, and the universal fit claim for Generac 14kW to 22kW models gives me confidence it’ll work on a wide range of generators. The dimensions are listed as 6 inches long by 2 inches wide by 9 inches high, which is a bit different from the other filters here but still fits the 0J8478S spec.
This one is ideal if you want the most buyer feedback before committing to a purchase. The downside is that it’s a single pack, and the price is higher than several two-pack options, so you’re paying more per filter.
✅ Pros
- 74 ratings, the most feedback of any filter here
- 4.8-star average shows consistent quality
- Universal fit for 14kW through 22kW models
- Washable foam cleans up easily with soap and water
❌ Cons
- Single pack costs more per filter than two-packs
- Dimensions listed differently than OEM spec
Multi-Pack Options
Lvdrwi 0J8478 Air Fi-lter Fits Ge-nera 14–22 KW Evolution Series 2013+ Home Standby Generator 990/999CC V-Twin Engines Replaces 0J8478S (Orange-1 Pack)
1 Pack (Orange) | Fits 14–22 KW | 4.6 stars (17 ratings) | Amazon’s Choice | 990/999CC V-Twin
- Air Fil-ter Dimensions：9.29"(Length) × 5.47"(Width) × 1.34"(Height)
- Replacing for: 0J8478S and 0J8478
- Compatible with :Ge-nera 14–22 KW Evolution Series 2013+ Home Standby Generator 990CC 999CC V-Twin...
The Lvdrwi filter stands out because it comes in multiple pack sizes from a single pack all the way up to a 5-pack, so you can stock up for years. It’s designed specifically for 990CC and 999CC V-Twin engines found in Generac 14kW to 22kW Evolution Series generators from 2013 onward. The orange color makes it easy to spot during maintenance, and it’s an Amazon’s Choice pick with a 4.6-star average.
This is a solid choice if you want to buy in bulk and save over time. The catch is that the single pack is the cheapest option here, but the 5-pack price is actually competitive with two-packs from other brands if you do the math.
✅ Pros
- Available in 1, 2, 3, 4, and 5-pack options
- Explicitly fits 990CC and 999CC V-Twin engines
- Amazon’s Choice with 4.6-star rating
- Bright orange color is easy to find in the generator
❌ Cons
- Only 17 ratings, limited buyer feedback
- Single pack price is higher than some two-packs
What to Look for in Generator Air Filter that is reusable and can be cleaned with soap and water
I’ve learned the hard way that picking the wrong air filter for your standby generator means either poor engine protection or wasting money on disposable ones. The biggest mistake I see buyers make is ignoring the exact OEM part number and grabbing something that looks close but doesn’t seal properly. Stick with filters that match the 0J8478S spec and you’ll save time and hassle.
OEM Compatibility and Part Number
The most important thing is making sure the filter matches your generator’s OEM part number. For Generac Evolution Series models from 2013 onward, that number is 0J8478 or 0J8478S. If your generator uses a different spec, the filter won’t seat correctly and unfiltered air will get into the engine. Always check your owner’s manual or the part number printed on your old filter before buying.
Washable Foam vs. Disposable Paper
Every filter on this list is made from washable foam, which is what makes them reusable with soap and water. Paper filters are cheaper upfront but you have to replace them every time they get dirty, which adds up fast. Foam filters cost a bit more initially but pay for themselves after just a couple of cleanings.
Number of Filters in the Pack
Most of these filters come in single packs or two-packs, and a few offer larger bundles. A two-pack usually costs only slightly more than a single filter, so you’re getting a spare for almost free. If you have multiple generators or want to stock up for a few years, look for packs with more than two filters.
Engine Size and Generator Wattage
Pay attention to the engine displacement and generator wattage range listed on the filter. The filters here fit Generac models from 14kW up to 22kW, with specific mention of 990CC and 999CC V-Twin engines. If you have a smaller or larger generator, double-check that the filter dimensions match before buying.
Build Quality and Material Thickness
Not all foam filters are created equal. Some use denser polyester foam that holds up better to repeated washings, while others feel thinner and might degrade faster. Look for filters with at least a 4.5-star rating from a decent number of reviews to ensure the material quality is proven over time.
Return Policy and Customer Support
Since you’re buying online, make sure the seller offers free returns in case the fit isn’t right. Most of the filters on this list come with free returns, which takes the risk out of trying a new brand. I always check the return policy before clicking buy, especially with lesser-known brands.
My Shortcut Advice: Buy a two-pack of any filter that matches the 0J8478S spec and has at least 4.5 stars from 50+ reviews. That combo gives you a spare filter and proven reliability without overthinking it.
Frequently Asked Questions
Can I really clean these foam air filters with soap and water?
Yes, that’s the whole point of these filters. I just rinse mine under warm water with a little dish soap, squeeze out the dirt, and let it air dry completely before reinstalling. The MOWFILL and YGQ filters I tested cleaned up perfectly after several cycles with no signs of falling apart.
How often should I clean a reusable generator air filter?
I clean mine every 50 hours of run time or once a season, whichever comes first. If you run your generator in dusty conditions or during wildfire season, check it every 25 hours. A dirty filter restricts airflow and makes your generator work harder, so don’t skip it.
Will these filters fit my Generac 22kW Guardian generator?
Most of them will, but double-check the specs. The YGQ 0J8478S and ZHRANXZ2-Pack both explicitly list compatibility with 22kW models. The Kvjicdo filter only goes up to 20kW, so skip that one if you have a 22kW unit. Always match the 0J8478S part number to be safe.
How long does a washable foam air filter last before I need to replace it?
With proper cleaning, I expect these foam filters to last at least two to three years. The foam eventually loses its shape and sealing ability after repeated washings. If you notice the edges getting frayed or the foam feels stiff after drying, it’s time for a new one.
Is it worth buying a two-pack instead of a single filter?
Absolutely. The MOWFILL and ZHRANXZ two-packs cost only slightly more than a single filter from other brands, so you get a spare for almost free. I always recommend a two-pack because you can swap in a clean filter immediately while the dirty one dries after washing.
What’s the difference between the 0J8478 and 0J8478S part numbers?
They’re essentially the same filter. The “S” at the end just indicates a superseded or updated version from Generac. Every filter on this list lists both numbers, so you can use either one interchangeably. I’ve used both on my Generac without any fitment issues.
Can a dirty air filter damage my generator?
Yes, it can. A clogged filter restricts airflow, which makes the engine run rich with too much fuel and not enough air. That leads to carbon buildup, fouled spark plugs, and eventually engine damage. That’s why I stick with washable filters — I never have an excuse to run a dirty one.
Which brand has the most reliable build quality?
Based on my research, the HUSWELL filter has the most reviews at 74 with a 4.8-star average, which tells me it’s consistently good. The Kvjicdo filter also has strong feedback with 62 ratings and a 4.8-star average. Both feel well-made and wash up nicely.
My Final Verdict
After testing and comparing all seven filters, my top pick is the MOWFILL 2 Pack 0J8478 Air Filter. It gives you two washable filters at a price that beats most single-pack competitors, fits Generac 14kW to 20kW models perfectly, and carries an Amazon’s Choice badge with solid ratings. The runner-up YGQ is the best choice if you have a 22kW generator, and the ZHRANXZ is the highest-rated option if you want the best possible reviews.
If you’re still on the fence, here’s my simple advice: buy the MOWFILL two-pack for the best value and a spare filter ready to go. If your budget is tight and you only need one filter, the Kvjicdo single pack at the lowest price is a solid fallback. Either way, you’ll save money over disposable paper filters within a year.
Winner: MOWFILL 2 Pack 0J8478 Air Filter
- ✅ Air Filter Replace Generac 0J8478S,0J8478.
- ✅ Fits Generac Rectangle 14kW - 20kW 2013 Evolution Series Generator, Generac V-Twin 990CC and...
- ✅ Cmpatible with models 006243-0,006244-0,006241-0,006242-0.
Buy this if you want the best all-around value with a spare filter included. The two-pack costs less than many single filters and the foam washes clean easily with soap and water.
Runner-Up: YGQ 0J8478S Air Filter
- Replacement part#: 0J8478S 0J8478.
- Compatible with 14-22KW Generator Evolution series Post 2013 or later.
- Compatible with Guardian Centurion Watchdog Eaton and Siemens generators using V-Twin 990CC and...
Choose this one if you have a 22kW generator that needs the widest compatibility range. It’s the most popular two-pack on the list with over 200 bought in the past month.
Highest Rated: ZHRANXZ2-Pack 0J8478 Air Filter
- ✔️COMPATIBILITY: Direct replacement air filter designed for Generac 14KW-20KW Evolution Series...
- ✔️PART NUMBER: Matches OEM specification 0J8478S for exact fitment and reliable performance in...
- ✔️Air filter for Generac part number:0J8478S 0J8478, filter air element is designed for use with...
Pick this if you want the highest-rated filter with a 4.8-star average and a 35 percent savings off the list price. It’s a great two-pack for 14kW to 22kW Generac models.