Is 20x21.5x1 air filter profitable to sell on Amazon United States?

The niche generates $160K/yr across 19 tracked products. 90-day search growth is +50.9%. Flapen's verdict: Skip it (48/100).

How competitive is the 20x21.5x1 air filter niche?

8 brands and 16 sellers compete. The top 5 products take 69% of clicks and top 5 brands hold 97% of demand.

What do buyers complain about in 20x21.5x1 air filter?

Top complaints mined from reviews: Quality-Overall, Filtration, Strength. The return rate is 1.0%.

When does demand for 20x21.5x1 air filter peak?

Demand peaks in Jun–Jul; the busiest month runs 5.2× the quietest.

What does it cost to enter the 20x21.5x1 air filter niche?

Listings span $18.15–$108.16; the average listing price is $45.52 (sweet spot $15–$100). The average incumbent carries 19,322 reviews — the moat a new listing must climb.

20x21.5x1 air filter

Skip it

Brand-locked demand (top 5 brands take 97% of clicks) — this niche doesn't clear our bar today.

Returns

Incredible1.0%

return rate — above 5% kills the launch gate

Avg price

Incredible$45.52

avg listing price — sweet spot $15–$100

Price range

Great$18.15–$108.16

cheapest to priciest tracked listing — scored on the share inside $15–$100

Growth

Good+50.9%

90-day search growth — must beat 0% to launch

Conversion

Good5.7%

search→purchase rate — share of searches ending in a sale

Market size

Okay$160K

$160K/yr · 62K searches

Competition

Okay69%

top-5 click share — leaders hold, buyers still browse

Quality gap

Bad4.7★

avg incumbent rating — lower means beatable quality

Review moat

Bad19,322.11

avg incumbent reviews — the moat a new listing must climb

Brand share

Bad97%

top-5 brand share — brand-locked demand

According to Flapen's Amazon United States niche tracking, 20x21.5x1 air filter is a $160K/yr Amazon United States market (62K searches/yr). The top 5 brands hold 97% of demand. Demand peaks in Jun–Jul. Verdict: Skip it — 48/100.

Data updated Jul 27, 2026 · scored weekly · How we score niches

20x21.5x1 air filter market data

Units sold / yr: 4K–5K; avg 100–250/product
Revenue / yr: $182K–$228K; units × avg price
Conversion rate: 5.7%
Avg BSR: #368
Page quality: 0%
Prime: 47%
Sponsored: 79%
Out of stock: 5.5%
Avg brand age: 85 months
Avg seller age: 190 days

Competition & brand share

The top 5 products take 69% of clicks — established leaders, but buyers still shop beyond them.

Brands

8 falling

Sellers

Top-5 brand share

97%

Top 20: 100%

Top-5 click share

69%

Top 20: 100%

Open market

Filter King46%
Filtrete34%
Filterbuy12%
Aerostar2%
Simply2%
Enviroflow1%
Open — no brand owns it (2 brands, 2%)

Demand & seasonality

Weekly Amazon search volume, last 104 weeks — +50.9% search growth over the last 90 days.

Peak months: Jun, Jul · busiest ÷ quietest = 5.2×

Open Trend

Top 20x21.5x1 air filter search terms

20x21x1 air filter22K/yr +47.0%5.0% conv.
20x21.5x1 air filter10K/yr +39.6%6.3% conv.
air filter 20x21x16K/yr +46.7%2.3% conv.
air filter 20x21.5x15K/yr +66.4%3.1% conv.
furnace filters 20x21x14K/yr +59.3%0.7% conv.
furnace filters 20x21.5x14K/yr +77.9%0.1% conv.
20x21.5x1 furnace filter3K/yr +69.1%0.7% conv.
20x21x1 furnace filter4K/yr +68.8%0.2% conv.
20 x 21 x 1 air filter3K/yr +22.2%6.0% conv.

All search terms

Top 20x21.5x1 air filter products on Amazon

Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 19 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

Filtrete 20x21.5x1 AC Furnace Air Filter MERV 8 MPR 700 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 19.69 x 21.19 x 0.81 in)

Filtrete$38.894.7★6,265 rev

Filter King 20x21x1 Air Filter (MERV 8) (6-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 20 x 21 x .75)

Filter King$55.894.7★2,030 rev

Filtrete 20x21x1 AC Furnace Air Filter MPR 700 MERV 8 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 19.69 x 20.69 x 0.81 in)

Filtrete$44.534.7★6,265 rev

Filter King 20x21x1 Air Filter (MERV 8) (3-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 20 x 21 x .75)

Filter King$37.214.7★1,771 rev

Filterbuy 20x21.5x1 Air Filter MERV 8 Essential Dust & Allergy Defense (6-Pack) Electrostatic Pleated HVAC AC Furnace Filters Replacement Made in USA (Actual Size: 19.88 x 21.50 x 0.75)

Filterbuy$50.214.7★51,098 rev

Newest

by launch date

Filtrete 20x21x1 AC Furnace Air Filter MPR 700 MERV 8 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 19.69 x 20.69 x 0.81 in)

Filtrete$44.536,265 rev

1y ago

Filtrete 20x21.5x1 AC Furnace Air Filter MPR 700 MERV 8 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 2-Pack (Actual Size 19.69 x 21.19 x 0.81 in)

Filtrete$27.33740 rev

1y ago

Generic Proairtek AF20211M08SWH Model 20x21x1 Air Filter MERV 8; Ideal for Anyone Wanting Clean Crisp Air in Their Home; Offers Enhanced Airflow and Efficiency; High-performance Filtration

Generic$18.151 rev

2y ago

Filtrete 20x21.5x1 AC Furnace Air Filter MERV 8 MPR 700 Tough on Pollen Easy on Airflow 3-Month Pleated 1-Inch Electrostatic Air Cleaning Filter 4-Pack (Actual Size 19.69 x 21.19 x 0.81 in)

Filtrete$38.896,265 rev

2y ago

Filter King 20x21x1 Air Filter (MERV 8) (3-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 20 x 21 x .75)

Filter King$37.211,771 rev

3y ago

What buyers say about 20x21.5x1 air filter

What buyers praise and complain about, mined from review topics.

What buyers love

Value For Money31%

“Cheap in price”

Filtration17%

“Great filter for the price”

Size-Overall15%

“Fits good”

Quality-Overall12%

“Good Quality Filters”

Advertised Vs Actual Product7%

“Works as advertised”

Ease Of Use4%

“Easy-peasy”

Efficiency2%

“Works well”

Strength2%

“They are sturdy”

Assembly/Installation1%

“Easy installation”

Locally Manufactured1%

“Made in the USA”

What buyers complain about

Quality-Overall19%

“Poor quality”

Filtration17%

“These air filters are not that good”

Strength10%

“Pretty flimsy, I guess theyll do the job”

Thickness9%

“Thinner than Filtrete filters”

Size-Overall7%

“Do not fit snug like they are supposed to”

Value For Money4%

“expensive for what you get”

Thin3%

“Man these feel super thin and flimsy”

Defective Material/Parts3%

“Three of them are damaged”

Heating3%

“My AC was not cooling properly”

Durability3%

“After 2 days, the filter frame folded and got pulled up out of position”

Top return reasons

Size-Overall74%

Filtration14%

Compatibility-Overall4%

Value For Money2%

Advertised Vs Actual Product1%

Defective Material/Parts1%

Quality-Overall1%

Certifications0%

Ease Of Use0%

Thickness0%

Common questions

Is 20x21.5x1 air filter profitable to sell on Amazon United States?: The niche generates $160K/yr across 19 tracked products. 90-day search growth is +50.9%. Flapen's verdict: Skip it (48/100).
How competitive is the 20x21.5x1 air filter niche?: 8 brands and 16 sellers compete. The top 5 products take 69% of clicks and top 5 brands hold 97% of demand.
What do buyers complain about in 20x21.5x1 air filter?: Top complaints mined from reviews: Quality-Overall, Filtration, Strength. The return rate is 1.0%.
When does demand for 20x21.5x1 air filter peak?: Demand peaks in Jun–Jul; the busiest month runs 5.2× the quietest.
What does it cost to enter the 20x21.5x1 air filter niche?: Listings span $18.15–$108.16; the average listing price is $45.52 (sweet spot $15–$100). The average incumbent carries 19,322 reviews — the moat a new listing must climb.