Industrial & Commercial Fan, Blower and Air Purification Equipment Manufacturing (NAICS 333413)

A Histometrics industry primer for public-market and private investors

1. Overview

This industry makes the machines that move and clean air at industrial and commercial scale: everything from the big exhaust fans on a factory roof, to the "blowers" that push air through a wastewater tank or a grain elevator, to the dust collectors and air-pollution scrubbers that keep a plant compliant, to the high-efficiency filtration systems that keep a data center or a semiconductor cleanroom running. If air needs to be pushed, pulled, or purified inside a building or an industrial process, a product from this industry is usually doing it.

Why an investor cares: air movement is unglamorous but structural. Almost every building and every industrial process needs it, replacement demand is steady, and the industry sits directly in the path of three of today's biggest capital-spending waves — data centers, semiconductor reshoring, and indoor-air-quality upgrades. It is also a classic "sell the machine, then sell the filters and parts for 20 years" business, which produces durable aftermarket revenue. Third-party performance verification through AMCA (Air Movement and Control Association) certification creates a modest but real barrier around laboratory capability, product data, selection software, and specification history — more consequential than the apparent simplicity of a fan housing might suggest [2].

The catch for public-market investors: there is essentially no U.S.-listed pure play. The largest and most focused American makers — Greenheck, Twin City Fan, New York Blower — are privately held [12][13][14]. Public exposure comes through diversified companies (filtration, flow control, HVAC) where fans and blowers are one segment among many. Private investors, by contrast, can own the operators directly, and much of the industry's ownership actually sits in family businesses, employee-owned firms, and private-equity roll-ups.

2. What it is and how it's structured

Scope. NAICS 333413 covers establishments primarily making industrial and commercial (a) fans and blowers and (b) air purification equipment — dust collectors, electrostatic precipitators, furnace filters, air washers, industrial air cleaners, and the like [1][3]. Practically, the output splits into a few families:

• Commercial air-movement: roof and wall exhaust fans, supply fans, ventilators, kitchen and garage exhaust, energy-recovery ventilators for offices, schools, hospitals, and warehouses.
• Heavy-duty industrial process fans: large custom or semi-custom centrifugal and axial fans for power generation, cement, mining, chemicals, and steel — engineered to order, high value, long lead times.
• Blowers: positive-displacement and centrifugal blowers (higher pressure than a fan, lower than a compressor) used in wastewater aeration, pneumatic conveying, and process air.
• Air purification equipment: dust collectors, fume and mist collectors, and industrial/commercial air cleaners and filtration housings.

What it excludes (named adjacent codes matter here, because much "air" money sits just outside this one):

• Air-conditioning and warm-air HVAC systems → NAICS 333415 (this is where AAON, and most of Trane/Carrier/Lennox, sit) [1].
• Air and gas compressors → NAICS 333912 (higher-pressure air machines are compressors, not blowers) [1].
• Household and portable consumer fans (ceiling, box, and floor fans; household vacuum cleaners; portable household air purifiers) → household appliance manufacturing (NAICS 335210) [1][3].
• Pumps for liquids → NAICS 333914. Replacement filter media is often made in paper/textile codes rather than here.

The boundary matters because many commercial "air purifier" market reports include consumer devices that Census expressly excludes, while overlooking furnace filters and large industrial pollution-control systems that Census includes [3].

Commercial models. The industry operates three broad models: (1) standard commercial fans and replacement filters are shorter-cycle products sold through representatives and distributors; (2) configured fans are assembled to order from established designs; (3) heavy process fans and pollution-control systems are engineered-to-order projects with longer lead times, milestone billing, working-capital exposure, and installation risk.

Ownership mix. The industry is fragmented and privately dominated. Federal statistics count 395 firms operating 479 establishments [8][4]. The biggest domestic operators are private and family- or employee-owned; the public-market presence is almost entirely divisions of large diversified manufacturers. That structure is central to how an investor gets in (Sections 4 and 10).

3. How big it is

The federal statistics for this specific industry code (our ground-truth figures):

Read the concentration numbers together: an HHI of 185.8 (a measure where anything under 1,500 is considered unconcentrated) and a CR4 of just 19.2% describe a highly fragmented industry — the four largest firms make less than a fifth of U.S. output, and it takes 50 firms to reach roughly three-quarters [8]. The SBA (U.S. Small Business Administration) treats a maker with up to 500 employees as "small" here, so most of the 395 firms qualify [16].

The undercount caveats (important). This is establishment-based manufacturing, so it is not undercounted the way government-dominated or gig-worker industries are. But the $8.0 billion federal figure understates the economic footprint an investor should picture, for three reasons:

1. It is domestic production, not U.S. consumption. A large share of fans, blowers, and filters used in the U.S. is imported, and imports are not in this shipments figure.
2. Air-moving revenue is scattered across adjacent codes. Fans built into HVAC units (333415), high-pressure air machines (333912), and consumer fans (335210) all live elsewhere, so "the fan business" in a commercial sense is much bigger than $8 billion.
3. The best-known names are private and diversified. Greenheck alone reports roughly $1.3 billion in revenue [12], and public filtration/flow companies book fan-and-blower sales inside broader segments — none of which maps cleanly to this code.

Third-party market researchers cite far larger numbers — e.g., a North American "industrial fans and blowers" market of roughly $3.4 billion (2025) and a global market in the $23–25 billion range (2024) [17]. These do not reconcile with the federal $8.0 billion because they use different scopes and geographies; treat them as directional, not comparable.

4. The investable universe

There is no U.S.-listed company whose business is industrial fans and air purification. The table below shows the public companies with the most meaningful exposure (a segment or business unit), followed by the private operators that actually dominate U.S. manufacturing. Tickers and scale are for orientation only.

Public companies with exposure (fans/blowers/air-cleaning is one part of a larger business):

Also carry minor exposure: Honeywell (NASDAQ: HON), 3M (NYSE: MMM) and Parker Hannifin (NYSE: PH) in filtration/air-cleaning; Regal Rexnord (NYSE: RRX) in air-moving motors and blowers; Nederman (Stockholm-listed) in industrial extraction and filtration; and non-U.S. ventilation specialists such as Volution Group (LSE: FAN) and Lindab (Nasdaq Stockholm).

Major private / other owners (this is where the industry actually lives) [6]:

The takeaway for a public-market investor: you are buying a theme through a portfolio, not a single stock. CECO and Donaldson are the most direct listed proxies for the industrial-air side; the pure operators require the private routes in Section 10.

5. How the money works

Owners in this industry make money the way most engineered-equipment manufacturers do — and the metrics that matter are the manufacturing ones, not restaurant or utility metrics.

Product mix drives margin. Two very different businesses live under one roof:

• Catalog / standard fans are close to a commodity — sold on price and lead time, exposed to import competition, thinner margins.
• Engineered, custom heavy-duty fans and blowers and air-pollution systems are project work — specified by engineers, built to order, higher margin, and much harder for a low-cost importer to displace. The more of a company's book is engineered and application-specific, the better and more defensible its margins.

The aftermarket is the profit engine. A fan, blower, or dust collector installed today runs for decades, and it needs replacement parts, bearings, wheels, and — for air purification — filter media that must be changed on a schedule. This is a razor-and-blades model: the recurring, higher-margin filter-and-parts stream on a large installed base is what smooths out the cyclical equipment sales. Donaldson explicitly leans on replacement-part strength [7], and Ingersoll Rand highlights the aftermarket on its Roots blower installed base [10].

Profitability benchmarks from public proxies. No authoritative industry-wide operating margin exists, but public-company segments provide analogues:

• Donaldson's Industrial Filtration Solutions segment (~$914M in FY2025 sales) sits within a broader Industrial Solutions segment that produced earnings before tax equal to 17.9% of segment sales. Steel, filter media, and petrochemical-based materials represent approximately 67% of company cost of sales [7].
• CECO Environmental reported 2025 sales of $774.4M and a 34.8% consolidated gross margin. Its Engineered Systems segment generated $544.3M of sales and $111.8M of segment profit, with year-end backlog of $793.1M — though CECO's portfolio extends into water treatment and energy [9].
• SPX Technologies' broader HVAC segment reported 2025 revenue of $1.518B and segment income of $372.6M, or 24.5% of revenue [22].

These are imperfect proxies — none maps cleanly to NAICS 333413 — but they illustrate the margin potential in engineered air equipment with aftermarket content.

What to watch on the P&L and beyond:

• Capacity utilization and backlog — for the project/engineered side, order backlog and book-to-bill signal future revenue; capacity utilization signals pricing power. Reported backlog should be assessed for cancellation rights, escalation clauses, customer deposits, and expected conversion dates.
• Input costs — steel, aluminum, copper, motors, bearings, drives, controls, filter media, resins, and freight are the main bill of materials; steel/aluminum tariffs and copper prices move gross margin directly.
• Gross and operating margin — the read-through on mix and pricing discipline.
• Cyclicality — new-equipment sales track nonresidential construction and industrial capital spending; the aftermarket is the counter-cyclical ballast.
• Energy efficiency as a sales lever — fans and blowers are large electricity consumers, so a more efficient unit can pay for itself; efficiency is a genuine driver of replacement demand even without a mandate.

6. What drives demand

• Data centers. The single hottest driver today. AI and cloud build-outs need enormous volumes of air handling, cooling airflow, and high-efficiency filtration; makers with data-center exposure (Munters, AAON, filtration suppliers) are seeing record orders [5][15][17]. DOE reports that U.S. data centers consumed 176 TWh (approximately 4.4% of national electricity) in 2023 and projects 325–580 TWh by 2028 [19]. However, rising rack densities are also driving adoption of direct-to-chip and other liquid-cooling technologies, which may reduce fan content per unit of computing while increasing demand for other air handlers, heat rejection, and facility ventilation.
• Semiconductor fabs and cleanrooms. Reshoring of chip manufacturing (aided by the CHIPS Act) drives demand for HEPA (high-efficiency particulate air) and ULPA (ultra-low penetration air) filtration and precise air handling; forecasters point to dozens of new fabs through 2030 [17].
• Nonresidential construction. Offices, hospitals, schools, and especially warehouses/logistics need commercial ventilation and exhaust — the bread-and-butter volume business.
• Industrial process and infrastructure. Power generation, cement, mining, chemicals, and municipal wastewater aeration (a core blower market) drive heavy-duty demand.
• Air-pollution control and emissions rules. Clean-air compliance sustains demand for dust collectors, fume collectors, and scrubbers — CECO's core [9]. EPA tightened the annual PM2.5 national ambient standard from 12.0 to 9.0 micrograms per cubic meter in 2024, potentially tightening permitting and emissions-control requirements for some facilities [20].
• Indoor air quality (IAQ). The post-COVID focus on ventilation and filtration (e.g., ASHRAE Standard 241 on infection risk) pushed filtration and air-cleaning upgrades in occupied buildings, particularly in schools, healthcare, and high-occupancy spaces [17][21]. Adoption and enforcement depend on building authorities and owners rather than automatic federal mandates.
• Reshoring and manufacturing capex. Broad U.S. factory build-out (CHIPS Act, Inflation Reduction Act incentives) lifts process-air and ventilation demand.

7. Regulation

Regulation touches this industry from two directions — product efficiency rules on what they make, and environmental/safety rules that create demand.

Energy-efficiency standards (in flux). The U.S. Department of Energy (DOE) spent years moving toward federal minimum-efficiency rules for commercial and industrial fans and blowers. It finalized a test procedure in 2023 built around the Fan Energy Index (FEI/CFEI) [18], then proposed an actual efficiency standard in January 2024 [25]. That proposed standard was withdrawn in January 2025, and DOE went further, proposing in May 2025 to withdraw its determination that fans and blowers are "covered equipment" under the Energy Policy and Conservation Act at all [25]. Net effect as of mid-2026: no federal minimum-efficiency standard is in force — DOE explicitly states there are currently no federal energy-conservation standards for these products [25]. That said, state and model building codes (California's Title 24, ASHRAE 90.1) and the industry's own AMCA certification still reference fan efficiency, so efficiency remains a real market requirement even without a federal mandate [18].

Fan Energy Index (FEI) evaluates the fan, motor, and controller at an actual operating point, favoring better aerodynamic design, efficient motors, variable-speed drives, and selection software that avoids oversized equipment. It can also accelerate replacement of inefficient installed equipment [26].

Environmental rules that drive demand. The EPA's Clean Air Act and state emissions rules underpin the air-pollution-control market (dust collectors, scrubbers) — tightening rules is a tailwind, not a cost. OSHA workplace ventilation and air-quality requirements do the same for industrial ventilation and dust/fume collection. OSHA guidance specifically calls for properly designed dust collection, containment, explosion relief, or suppression where combustible dust is present [27].

Trade and safety. Steel and aluminum tariffs and duties on imported Chinese fans affect both input costs and competitive pricing. UL and AMCA certifications gate what can be sold into regulated commercial construction.

8. Competitive dynamics and consolidation

The industry is fragmented (HHI 185.8; CR4 19.2%) [8] and competes on a mix of engineering, application expertise, installed base, brand, capital for custom fabrication, and manufacturer's-rep distribution networks. Commodity catalog fans face real price pressure from imports; engineered heavy-duty and air-pollution systems are far more defensible.

The structure is best described as fragmented by firm count but segmented by application. Catalog commercial ventilation rewards brand, representative coverage, selection software, and delivery. Heavy industrial fans reward engineering history, reference installations, and field service. Dust collection and emissions systems add process knowledge, safety engineering, and regulatory competence. A manufacturer strong in one segment need not be a meaningful competitor in another.

Consolidation is a live theme:

• Strategic roll-ups of flow/air brands. Ingersoll Rand has assembled a portfolio of compressor, vacuum, and blower brands (Gardner Denver, CompAir, and, since 2023, the Roots blower/centrifugal-compressor line bought from Chart Industries) [10].
• Major M&A reshaping ownership. Baker Hughes completed its acquisition of Chart Industries in July 2026, bringing Howden's industrial fans and blowers under the Baker Hughes umbrella [11].
• Acquisitive listed platforms. CECO Environmental has grown its industrial-air and air-quality business substantially through acquisitions [9].
• HVAC and filtration majors (Daikin owning AAF; Munters buying data-center-cooling assets) keep pulling adjacent air-movement capability under bigger roofs [14][5].
• Private-equity and family/ESOP structures dominate the operator base, which itself is a steady source of deal flow as founders and families seek liquidity.

9. Risks

• Cyclicality. New-equipment demand tracks nonresidential construction and industrial capex; a downturn hits order books. The aftermarket cushions but does not eliminate this.
• Input-cost and tariff exposure. Steel, aluminum, copper, motors, bearings, drives, controls, filter media, resins, and freight are the cost base; tariff and commodity swings squeeze margins if they cannot be passed through. Selective supplier concentration can create delivery problems.
• Import competition. Low-cost imports pressure the commodity end of the catalog business.
• Demand concentration in a few hot end-markets. The data-center/AI capex wave is a powerful driver — and a risk if that spending decelerates. Additionally, liquid-cooling adoption in high-density compute environments may reduce fan content per unit of computing. Project businesses also face lumpy, customer-concentrated backlogs.
• Regulatory whiplash. The on-again/off-again federal efficiency standard makes product-planning and the payback case for efficient units harder to underwrite.
• Skilled-labor and fabrication capacity constraints on the engineered/custom side. Custom equipment depends on application knowledge that is difficult to replace quickly.
• Combustible-dust liability. A poorly designed dust collector can concentrate rather than eliminate an explosion hazard; combustible-dust systems are especially sensitive to proper design, and manufacturers face testing, certification, and liability exposure [27].
• Project execution risk. Large engineered systems carry customer-credit, cancellation, site-access, and fixed-price risk. Fixed-price overruns, redesigns, site delays, and liquidated damages can erase margins.
• For public proxies, dilution of the theme: in a Donaldson, Ingersoll Rand, or AMETEK, fan/blower/air results are diluted by unrelated segments, so the "pure" exposure is limited.

10. How to invest and the outlook

Public-market routes. Because there is no listed pure play, investors build exposure through diversified names, accepting that fans and air purification are one part of the story:

• Most direct industrial-air proxies: CECO Environmental (Nasdaq: CECO) and Donaldson (NYSE: DCI).
• Blowers and flow: Ingersoll Rand (NYSE: IR), AMETEK (NYSE: AME), Baker Hughes (Nasdaq: BKR) via Howden (following Chart acquisition) [11].
• Air treatment and the data-center-air theme: Munters (Nasdaq Stockholm: MTRS) and, adjacent, AAON (Nasdaq: AAON).
• Engineered air movement: SPX Technologies (NYSE: SPXC) within its broader HVAC segment.
• Global filtration angle: Daikin (Tokyo: 6367) (owns AAF), plus Honeywell, 3M, and Parker Hannifin as minor filtration exposures.
• Foreign-listed ventilation specialists: Systemair (Nasdaq Stockholm: SYSR), Nederman, Volution Group (LSE: FAN), and Lindab. Valuation multiples, dividend yields, and segment disclosures vary widely across these — size the "fan" exposure inside each before treating any as a play on this industry.

Private-market routes. This is where the purest operators are — Greenheck, Twin City Fan, New York Blower, Chicago Blower, Loren Cook, and Camfil are all private [12][13][14][24]. Private investors reach them through direct/family ownership transitions, employee-ownership (ESOP) structures, private-equity buyouts and roll-ups of regional fan/blower/filtration makers, and the distributor and manufacturer's-rep businesses that sit alongside them. Given the fragmentation and steady aftermarket cash flows, this industry is a natural hunting ground for buy-and-build private equity.

Private-market underwriting should separate standard products, configured products, custom projects, and recurring aftermarket revenue; verify AMCA certifications and specification history; examine representative and distributor concentration; normalize backlog; test price-cost escalation rights; assess installed-base service penetration; and review combustible-dust, emissions, and warranty liabilities.

Outlook (forward-looking judgment). The demand backdrop looks favorable into the second half of the decade: data centers, semiconductor reshoring, indoor-air-quality upgrades, wastewater and infrastructure spending, and broad manufacturing capex all pull in the same direction, and the large installed base keeps aftermarket revenue steady. The main offsets are construction cyclicality, input-cost and tariff volatility, import competition at the commodity end, liquid-cooling substitution in high-density data centers, and the risk that a few concentrated end-markets (especially AI-driven data-center spending) cool. The recent federal retreat from mandatory fan-efficiency standards removes a near-term regulatory push, but persistent state codes, energy costs, and customer economics keep efficiency and replacement demand intact. For most public investors this remains a theme played through a basket; for private investors it is a fragmented, cash-generative, consolidating field of operators.

---

Sources

1. U.S. Census Bureau, "North American Industry Classification System (NAICS) 2022 — 333413 Industrial and Commercial Fan and Blower and Air Purification Equipment Manufacturing (definition and cross-references)," 2022. https://www.census.gov/naics/
2. Air Movement and Control Association International (AMCA), "AMCA Certified Ratings Program," 2026. https://www.amca.org/certify/
3. U.S. Census Bureau, "2022 NAICS Manual (authoritative definitions and exclusions)," 2022. https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf
4. U.S. Census Bureau, "County Business Patterns 2023 — NAICS 333413 (establishments, employment, annual payroll)," 2023 (Histometrics ingested federal statistics). https://data.census.gov/
5. Munters Group AB, "Interim report / Full-year report 2024" and "Annual & Sustainability Report 2025," 2024–2025. https://www.munters.com/en-us/news-media/press-releases/
6. IndustrySelect, "Top U.S. Manufacturers of Blowers and Fans," and ensun, "Top 100 Industrial Fan Manufacturers in the United States" (landscape of leading private and public makers), 2026. https://www.industryselect.com/blog/top-us-manufacturers-of-blowers-and-fans
7. Donaldson Company, Inc., "Form 10-K, Fiscal Year 2025 (Annual Report — segments, revenue, cost structure)," 2025. https://www.sec.gov/Archives/edgar/data/29644/000002964425000098/dci-20250731.htm
8. U.S. Census Bureau, "2022 Economic Census — Concentration statistics for NAICS 333413 (receipts, firm count, CR4/CR8/CR20/CR50, HHI)," 2022 (Histometrics ingested federal statistics). https://data.census.gov/
9. CECO Environmental Corp., "Form 10-K, Fiscal Year 2025 (Annual Report — segments, revenue, margins, backlog)," 2025. https://www.sec.gov/Archives/edgar/data/3197/000119312526085815/ceco-20251231.htm
10. Ingersoll Rand Inc., "Ingersoll Rand Completes Acquisition of Roots from Chart Industries," 2023; company revenue disclosures 2024. https://investors.irco.com/news/
11. Baker Hughes Company, "Completion of Chart Industries Acquisition," Form 8-K, July 2026. https://www.sec.gov/Archives/edgar/data/1701605/000119312526305477/d105425dex991.htm
12. Greenheck Group, "About Us — Overview" and PrivCo/company profile (revenue, employees, plants), 2026. https://www.greenheck.com/about-us/overview
13. Twin City Fan Companies, Ltd., "Who We Are" (Barry-family ownership, ESOP); Kona Equity company profile (revenue), 2026. https://twincityfan.com/
14. AAF International / AAF Flanders and Camfil AB company profiles; MarketsandMarkets, "Panel Filters Market — leading players (Camfil, AAF International)," and New York Blower company overview, 2026. https://www.aafintl.com/; https://www.camfil.com/en; https://www.nyb.com/
15. AAON, Inc., "Fiscal 2025 results" and StockAnalysis company overview (revenue), 2026. https://stockanalysis.com/stocks/aaon/
16. U.S. Small Business Administration, "Table of Small Business Size Standards — NAICS 333413 (500 employees)," 2023 (Histometrics ingested federal statistics). https://www.sba.gov/document/support-table-size-standards
17. GMInsights, "Industrial Fans and Blowers Market" and "North America Industrial Fans and Blowers Market," and IndexBox, "Cleanroom / data-center / semiconductor air-filtration demand forecasts," 2025–2026. https://www.gminsights.com/industry-analysis/industrial-fans-and-blowers-market; https://www.indexbox.io/
18. Air Movement and Control Association International (AMCA), "2025 Update on U.S. Fan-Efficiency Codes and Regulations," and U.S. Department of Energy, "Test Procedure for Fans and Blowers (final rule)," Federal Register, 2023–2025. https://www.amca.org/educate/articles-and-technical-papers/amca-inmotion-articles/2025-update-on-u.s.-fan-efficiency-codes-and-regulations.html
19. U.S. Department of Energy and Lawrence Berkeley National Laboratory, "Report on Data Center Electricity Demand," 2024. https://www.energy.gov/articles/doe-releases-new-report-evaluating-increase-electricity-demand-data-centers
20. U.S. Environmental Protection Agency, "Particle Pollution Designations — 2024 Revised PM2.5 Standard," 2024. https://www.epa.gov/particle-pollution-designations/particle-pollution-designations-memorandum-and-data-2024-revised
21. ASHRAE, "Standard 241 — Control of Infectious Aerosols (overview)," 2023. https://www.ashrae.org/about/news/2023/ashrae-publishes-standard-241-control-of-infectious-aerosols
22. SPX Technologies, Inc., "Form 10-K, Fiscal Year 2025 (Annual Report — HVAC segment revenue and margins)," 2025. https://www.sec.gov/Archives/edgar/data/88205/000008820526000008/spxc-20251231.htm
23. Systemair AB, "Annual and Sustainability Report 2024/25," 2025. https://group.systemair.com/news/press-releases/2025/systemair-annual-and-sustainability-report-202425/
24. Chicago Blower Corporation, "Company overview," 2026. https://www.chicagoblower.com/
25. U.S. Department of Energy, "Energy Conservation Standards for Fans and Blowers" (NOPR Jan. 2024; withdrawal Jan. 2025) and "Proposed Withdrawal of Determination of Fans and Blowers as Covered Equipment" (May 2025); DOE Fans and Blowers Rulemaking Page, Federal Register. https://www.energy.gov/cmei/buildings/fans-and-blowers
26. Air Movement and Control Association International (AMCA), "About Fan Energy Index (FEI)," 2026. https://www.amca.org/advocate/energy-efficiency-and-system-performance/about-fan-energy-index/
27. U.S. Occupational Safety and Health Administration (OSHA), "Combustible Dust — Guidance," 2026. https://www.osha.gov/publications/3371combustible-dust