---
title: "20x21.5x1 Air Filter — $160K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/tools-home-improvement/20x21-5x1-air-filter"
last_updated: "2026-08-08T06:59:33.007Z"
locale: en
meta:
description: "Niche score 48/100 · $160K/yr market · 62K searches/yr · $45.52 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 48/100 · $160K/yr market · 62K searches/yr · $45.52 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "20x21.5x1 Air Filter — $160K/yr Amazon US Niche (2026) - Flapen"
---
# **20x21.5x1 air filter**
**Skip it**
Brand-locked demand (top 5 brands take 97% of clicks) — this niche doesn't clear our bar today.
Market size 34Growth 69Conversion 64Competition 27Returns 95Price range 88Avg price 95Brand share 9Review moat 17Quality gap 20
**Returns**
**Incredible****1.0%**
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**
**Good****5.7%**
search→purchase rate — share of searches ending in a sale
**Market size**
**Okay****$160K**
$160K/yr · 62K searches
**Competition**
**Okay****69%**
top-5 click share — leaders hold, buyers still browse
**Quality gap**
**Bad****4.7★**
avg incumbent rating — lower means beatable quality
**Review moat**
**Bad****19,322.11**
avg incumbent reviews — the moat a new listing must climb
**Brand share**
**Bad****97%**
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 ~~](https://flapen.com/research/methodology)
## **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**
**16**
**Top-5 brand share**
**97%**
Top 20: 100%
**Top-5 click share**
**69%**
Top 20: 100%
**Open market**
**2%**
- 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.
2K2KSpike '25Prime Day '25Spike '26Prime Day '26 seasonSepDecMarJunAugNovMarMay
Peak months: Jun, Jul · busiest ÷ quietest = 5.2×
[**Open Trend **](https://flapen.com/research/us/tools-home-improvement/20x21-5x1-air-filter/trend)
## **Top 20x21.5x1 air filter search terms**
- **20x21x1 air filter**22K/yr+47.0%5.0% conv. - **20x21.5x1 air filter**10K/yr+39.6%6.3% conv. - **air filter 20x21x1**6K/yr+46.7%2.3% conv. - **air filter 20x21.5x1**5K/yr+66.4%3.1% conv. - **furnace filters 20x21x1**4K/yr+59.3%0.7% conv. - **furnace filters 20x21.5x1**4K/yr+77.9%0.1% conv. - **20x21.5x1 furnace filter**3K/yr+69.1%0.7% conv. - **20x21x1 furnace filter**4K/yr+68.8%0.2% conv. - **20 x 21 x 1 air filter**3K/yr+22.2%6.0% conv. [**All search terms **](https://flapen.com/research/us/tools-home-improvement/20x21-5x1-air-filter/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.
0%5%$8K10%$16K15%$24K20%$32K1101001K10K100K1.0M Reviews — right = deep review moatMarket share (90d) ≈ est. sales
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
[1**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**$38.89**4.7★6,265 rev](https://www.amazon.com/dp/B0CZBWF3LM) [2**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**$55.89**4.7★2,030 rev](https://www.amazon.com/dp/B07HFFDRDW) [3**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**$44.53**4.7★6,265 rev](https://www.amazon.com/dp/B0F9LT2DCT) [4**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**$37.21**4.7★1,771 rev](https://www.amazon.com/dp/B0BV4PNGV1) [5**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**$50.21**4.7★51,098 rev](https://www.amazon.com/dp/B01MQT48EL)
**~~View all top sellers →~~**
### **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**$44.53**6,265 rev1y ago](https://www.amazon.com/dp/B0F9LT2DCT) [**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**$27.33**740 rev1y ago](https://www.amazon.com/dp/B0F9LQ3KXJ) [**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**$18.15**1 rev2y ago](https://www.amazon.com/dp/B0D7GDH2TC) [**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**$38.89**6,265 rev2y ago](https://www.amazon.com/dp/B0CZBWF3LM) [**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**$37.21**1,771 rev3y ago](https://www.amazon.com/dp/B0BV4PNGV1)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Filter King 20x21x1 Air Filter (MERV 8) (12-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 20 x 21 x .75)**Filter King**$108.16**4.7★**▲ 117%**](https://www.amazon.com/dp/B07HFHHJ7C) [**Simply 20x22x1 Air Filter Merv 8 6 Pack For Home AC Furnace & HVAC (Actual Size: 19.75x21.75x0.75) DUST Pet & Allergy Control**Simply**$42.31**4.7★**▲ 116%**](https://www.amazon.com/dp/B09RHLPY1Q) [**Filter King 20x21x1 Air Filter (MERV 8) (4-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 20 x 21 x .75)**Filter King**$45.97**4.7★**▲ 92%**](https://www.amazon.com/dp/B07FQVWP8P) [**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**$55.89**4.7★**▲ 73%**](https://www.amazon.com/dp/B07HFFDRDW) [**Filter King 20x21.5x1 Air Filter (MERV 8) (6-Pack) Dust & Allergy Control AC Furnace Filters MADE IN USA HVAC Pleated Electrostatic (Actual Size: 20 x 21.5 x .75)**Filter King**$49.55**4.7★**▲ 43%**](https://www.amazon.com/dp/B07HFHHJ79)
**~~View all trending →~~**
## **What buyers say about 20x21.5x1 air filter**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Value For Money**31%
*“Cheap in price”*
**Filtration**17%
*“Great filter for the price”*
**Size-Overall**15%
*“Fits good”*
**Quality-Overall**12%
*“Good Quality Filters”*
**Advertised Vs Actual Product**7%
*“Works as advertised”*
**Ease Of Use**4%
*“Easy-peasy”*
**Efficiency**2%
*“Works well”*
**Strength**2%
*“They are sturdy”*
**Assembly/Installation**1%
*“Easy installation”*
**Locally Manufactured**1%
*“Made in the USA”*
### **What buyers complain about **
**Quality-Overall**19%
*“Poor quality”*
**Filtration**17%
*“These air filters are not that good”*
**Strength**10%
*“Pretty flimsy, I guess theyll do the job”*
**Thickness**9%
*“Thinner than Filtrete filters”*
**Size-Overall**7%
*“Do not fit snug like they are supposed to”*
**Value For Money**4%
*“expensive for what you get”*
**Thin**3%
*“Man these feel super thin and flimsy”*
**Defective Material/Parts**3%
*“Three of them are damaged”*
**Heating**3%
*“My AC was not cooling properly”*
**Durability**3%
*“After 2 days, the filter frame folded and got pulled up out of position”*
### **Top return reasons **
**Size-Overall**74%
**Filtration**14%
**Compatibility-Overall**4%
**Value For Money**2%
**Advertised Vs Actual Product**1%
**Defective Material/Parts**1%
**Quality-Overall**1%
**Certifications**0%
**Ease Of Use**0%
**Thickness**0%
## **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.
## **Related niches in Tools & Home Improvement**
- 73 [**solar outdoor lights**](https://flapen.com/research/us/tools-home-improvement/solar-outdoor-lights)$30.2M/yr+39.8%**Launch it**- 73 [**shower lamp**](https://flapen.com/research/us/tools-home-improvement/shower-lamp)$2.8M/yr+30.2%**Launch it**- 73 [**solar flowers**](https://flapen.com/research/us/tools-home-improvement/solar-flowers)$607K/yr+52.0%**Worth a look**- 73 [**american flag lights**](https://flapen.com/research/us/tools-home-improvement/american-flag-lights)$465K/yr+736.5%**Worth a look**- 73 [**solar fairy lights**](https://flapen.com/research/us/tools-home-improvement/solar-fairy-lights)$3.5M/yr+64.6%**Launch it**- 73 [**solar watering can with cascading lights**](https://flapen.com/research/us/tools-home-improvement/solar-watering-can-with-cascading-lights)$304K/yr+124.3%**Worth a look**[**All Tools & Home Improvement niches **](https://flapen.com/research/us/tools-home-improvement)