As an HVAC manufacturer and wholesale supplier, we watch demand for air purifiers move in two very different patterns, and the distributors who do well understand both.
The first is a slow structural rise. Urbanisation, post-pandemic awareness of indoor air, and rising household income have moved air purifiers from accessory to appliance in a lot of markets. That demand grows steadily and is reasonably easy to forecast.
The second is episodic, and it is where most distributors get caught out. A regional haze event, a wildfire season, a winter inversion over a northern city, and demand for HEPA air purifier wholesale stock goes vertical in a matter of days. Retailers clear their shelves in a week and then spend a month trying to resource, usually at the worst possible moment to be negotiating.
This article is for the distributor side of that equation: which markets carry which kind of demand, the technical specification that actually matters in a smoke-affected market and is routinely got wrong, and how MOQ, OEM branding and lead times work in practice.
What a HEPA Air Purifier Actually Filters
Start with the specification, because the number everyone quotes is usually quoted loosely and the loose version causes commercial problems.
HEPA stands for High-Efficiency Particulate Air, and there are two standards behind it:
- United States: a HEPA filter captures 99.97% of particles at 0.3 microns.
- Europe, EN 1822: graded classes. H13 captures at least 99.95% and H14 at least 99.995%, measured at the Most Penetrating Particle Size rather than at a fixed 0.3 microns.
Those are not the same claim, and “almost 100% at 0.3 microns” is not a specification anyone can buy against. If you are selling into a market with procurement standards, quote the class and the standard. H13 is the usual commercial grade; H14 is specified where the application demands it.
Why 0.3 microns and not something smaller? Because that size is the hardest to catch. Larger particles are intercepted and impacted directly; much smaller particles move erratically enough to be captured by diffusion. The efficiency minimum sits in between, which is why the standards measure there.
A HEPA filter captures dust, pollen, mould spores, bacteria, smoke particulate and the PM2.5 fraction generally. What it does not do matters more than what it does, and that brings us to the point most relevant to your markets right now.
Why Haze Needs Carbon, Not Just HEPA
This is the single most commercially important thing in this article, and it is where a lot of stock gets sold into the wrong market.
HEPA removes particles. It does nothing to gases. The mechanism is physical capture in a fibre matrix, and a gas molecule passes straight through.
Smoke from forest and peat fires is not only particulate. It carries carbon monoxide, sulphur dioxide, nitrogen oxides, volatile organic compounds and the aromatic compounds that produce the smell. Peat fires in particular burn by smouldering rather than flaming combustion, which produces a higher proportion of gases and ultrafine particulate than an open flame does.
The practical consequence is one your retailers will hear about from customers. A HEPA-only unit running in a haze-affected room will show a clean reading on a PM2.5 monitor, and the room will still smell of smoke. The smell is the gas fraction. A customer who paid for clean air and can still smell the fire concludes the product does not work, and that complaint lands on the retailer.
So for any market exposed to smoke, specify units with activated carbon in meaningful quantity, not a thin carbon-coated pre-filter sheet. Adsorption capacity scales with the mass of carbon, and a few grams bonded to a mesh will saturate in days under haze loading.
Two further points worth passing on to your retail channel:
- Carbon saturates silently. Unlike a HEPA filter, which visibly loads with dust and restricts airflow, activated carbon gives no external sign that it is exhausted. It simply stops adsorbing. Replacement has to run on a schedule, and under haze loading that schedule is much shorter than the manual’s normal-conditions figure.
- No filter removes carbon dioxide. If a room is sealed up against outdoor smoke, CO2 accumulates from the occupants and causes the drowsiness and poor concentration people often blame on the purifier. That is a ventilation problem, and it is why fresh air units with heat recovery sell alongside purifiers in these markets rather than instead of them.
Our comparison of HEPA and activated carbon filters covers the two mechanisms in detail, and is worth sending to retail staff who have to explain this at the counter.
Market Demand: Two Different Buying Patterns
Distributors tend to treat air purifiers as one product with one demand curve. It is two.
Episodic Markets: Smoke and Seasonal Pollution
Southeast Asia is the clearest case. Haze from land and forest fires in Sumatra and Kalimantan drifts across Singapore, Malaysia, Brunei and parts of the Philippines, and it is a recurring rather than a one-off phenomenon. Major episodes have hit in 2013, 2015, 2019, 2023 and again in 2026, when Singapore’s PSI reached its highest level of the year, Johor closed all its schools for two days, and Sarawak closed schools across ten district education offices.
The commercial pattern repeats with the haze. Retail shelves empty within about a week of the first unhealthy readings. Distributors who hold stock sell it at full margin. Distributors who do not spend the next four to six weeks sourcing, paying air freight, and arriving as the event subsides.
Other markets with the same episodic shape, driven by different causes:
- Northern India and Pakistan, post-harvest stubble burning combined with winter inversion, roughly October to January.
- Northern Thailand, Laos and northern Vietnam, agricultural burning in the February to April dry season.
- Western North America and Australia, wildfire seasons that have lengthened and intensified.
- Northern China and Mongolia, winter heating season combined with spring dust events.
The strategic point for a distributor is that these events are seasonal, not random. The window to place a wholesale order is the quiet quarter before the season, not the week the readings spike. By then every supplier in the market is quoting on allocation.
Structural Markets: High Awareness, Occasional Deterioration
The second pattern is steadier and in the long run more valuable, and it is easy to dismiss.
Markets with generally good outdoor air still buy air purifiers in volume, for reasons that have nothing to do with a pollution crisis:
- Allergy and asthma management. Pollen, dust mite debris and pet dander are indoor problems regardless of outdoor air quality, and they are year-round in temperate climates.
- Health awareness and disposable income. Higher-income markets buy preventively. The purchase is framed as wellness rather than emergency.
- Airtight modern construction. The better a building is sealed for energy efficiency, the less it ventilates passively, and the more indoor-generated pollutants accumulate. Cooking is a substantial PM2.5 source in its own right, which we cover in reducing PM2.5 from cooking.
- Institutional procurement. Schools, clinics, offices and hotels increasingly specify filtration as policy rather than as a reaction, which produces repeat tender-based orders rather than consumer spikes.
- Occasional deterioration. Even clean-air markets have bad weeks: a nearby wildfire, a still cold snap, construction next door. The households that already own a purifier are the ones who recommend it when that happens.
A distributor working only the episodic markets has a volatile business. One working both has a base load that funds the stock position for the spikes.
Commercial and Institutional Segments
Across both patterns, the commercial segment behaves differently from retail and is often where the margin is. Hotels, offices, schools, clinics, restaurants and gyms have large volumes, long operating hours and air change requirements, which pushes them toward higher-capacity units and toward ducted or fresh air equipment rather than portable consumer models.
They also buy in quantity on a single decision, and they replace filters on contract, which produces recurring revenue a consumer sale does not. Our XFQT-60-01S ion catalytic fresh air purifier is built for that duct-mounted commercial duty, and the KJ200F-A01 covers larger room volumes.
Why Buy Wholesale
The arithmetic is straightforward but worth setting out, because the benefit is not only unit price.
Unit cost falls with quantity. Tooling, setup and production scheduling are fixed costs recovered across the run, so a larger order spreads them further.
Supply continuity. In an episodic market this is worth more than the discount. The distributor who can ship the week the readings spike captures the whole season; the one waiting on a production slot captures the tail of it.
Lower landed cost per unit. Consolidating into fewer, fuller shipments reduces freight and handling per unit, and a full container is materially cheaper per unit than LCL.
Pricing flexibility downstream. A lower landed cost lets you compete on price in a crowded marketplace without surrendering margin, or hold price and take the margin.
One caution on the arithmetic that often gets missed: compare on landed cost, not FOB price. Freight, insurance, duty and the HS classification applied at the destination all move the real number, sometimes by more than the unit price difference between two suppliers. Air purifiers generally classify under HS 8421.39, filtering or purifying machinery for gases, and the duty that attracts varies by destination. Our guide to HS codes for HVAC products sets out the classifications.
OEM and ODM: Selling Under Your Own Brand
The strongest reason to buy wholesale rather than resell someone else’s brand is that it lets you build an asset of your own.
Under an OEM arrangement you take an existing proven design and apply your own branding, packaging, colour and documentation. Lead time is short because the tooling exists, and the risk is low because the product is already in production.
Under an ODM arrangement the manufacturer develops to your specification: different capacity, a different filter configuration, a different control interface, a housing of your own. Higher commitment, longer lead time, and a product nobody else can sell. Our explainer on what ODM means sets out the difference properly.
For a distributor entering a haze-exposed market, there is a sensible middle path. Start with OEM on a standard model to establish the brand and prove the demand, and move to ODM only once volume justifies the tooling. That sequencing avoids the common mistake of committing to a custom housing before anyone has bought the first container.
Either route builds something a pure reseller never has: a brand customers ask for by name, rather than a price position anyone can undercut next month.
MOQ, Lead Times and Negotiation
Concrete figures, since abstract discussion of MOQ helps nobody.
Our minimum order quantity for air purifiers and fresh air units is 500 units, and that figure applies to own-brand and private label orders, where there is branding, packaging and documentation to set up. Non-branded units can be bought in smaller quantities, including at retail, so a distributor can sample and test the market before committing to a branded run. MOQ is negotiable in either case and worth discussing rather than assuming.
What drives an MOQ is usually material batch size, packaging print runs and production scheduling, not supplier preference. So the productive question is not “can you lower it” but “what drives it”, and the answers give you levers:
- Accept standard colour and standard packaging on the first order.
- Combine several models into one production run so the setup spreads.
- Place a blanket order at volume pricing with staged releases across the season.
- Take the first order at standard specification and introduce customisation at the second.
On lead times, build the calendar honestly. Production typically runs 25 to 45 days after specification sign-off, plus 25 to 40 days sea freight to Southeast Asian ports and considerably longer further afield. Chinese New Year stops production for two to four weeks with a slowdown either side, so stock intended for a February to April burning season has to be ordered in November, not January.
And negotiate on more than unit price. Freight terms, packaging cost, spare filter stock and after-sales support are all on the table, and spare filters in particular matter more than they look: a distributor holding replacement filters during a haze event has a second revenue stream while competitors are out of stock on everything.
Specification Checklist for a Smoke-Affected Market
If you are placing a first order for a haze-exposed market, confirm these before signing:
- HEPA class stated as a standard, H13 or H14 to EN 1822, or 99.97% at 0.3 microns to the US definition. Not “almost 100%”.
- Activated carbon by mass, not as a coated pre-filter. Ask for the quantity.
- CADR rated for the room sizes your market actually has. An undersized unit in a large living room will disappoint regardless of filter class.
- Filter availability and price, with stock held for the season. A purifier whose filters cannot be obtained is a complaint waiting to happen.
- Certifications for your destination market, with the Declaration of Conformity and test reports, not a one-page certificate.
- Noise level at the speed people will actually run it. Quoting the figure at minimum fan speed is standard practice and tells the buyer nothing about night-time use.
- No ozone-generating function where you are selling into schools, clinics or childcare. Ozone is a lung irritant and several markets restrict it.
Where to Point Customers Who Want to Understand the Numbers
During a haze event the question your retail channel gets most is not about products. It is what the readings mean, and a retailer who can answer that sells more than one who cannot.
Two references worth putting in front of staff and customers: our explainer on the air quality index, its numbers, colours and health impact, and our data on PM2.5 levels in major cities. The health background is covered in PM2.5 health effects.
Working With Legom
Jiaxing Legom Technology Co., Ltd. manufactures air purification and HVAC equipment from our facility in Jiaxing, Zhejiang, and supplies more than 90 countries.
Our air purifier range covers portable household units, higher-capacity commercial models, ducted and fresh air equipment, and automotive units, which sell well in haze markets where people commute in traffic through the smoke. We also manufacture water purifiers, which distributors often carry alongside.
On the OEM and ODM side, our OEM and ODM service covers branding, packaging, filter configuration, control interface, capacity and the documentation pack for your destination market. Background on our manufacturing position is in air purifier manufacturing in China, and on filter sourcing specifically in choosing a HEPA filter supplier.
Tell us the destination market, the room sizes you are selling into and whether smoke is part of the picture, and we will come back with the filter configuration and the documentation position before we come back with a price. If you are planning for a burning season, talk to us in the quiet quarter rather than the week the readings spike.
Frequently Asked Questions
Does a HEPA air purifier remove haze?
Partly. HEPA captures the particulate fraction, including PM2.5, which is the component with the clearest health impact. It does nothing to the gases in smoke: carbon monoxide, sulphur dioxide, nitrogen oxides, VOCs and the compounds that produce the smell. For a smoke-affected market, specify units with activated carbon by mass alongside the HEPA stage, or customers will have clean PM2.5 readings in a room that still smells of fire.
What HEPA class should I specify?
H13 to EN 1822, meaning at least 99.95% efficiency at the most penetrating particle size, is the usual commercial grade. H14 at 99.995% where the application requires it. The US equivalent definition is 99.97% at 0.3 microns. Quote the class and the standard rather than a percentage on its own.
What is the MOQ for wholesale air purifiers?
500 units for own-brand and private label orders, where branding, packaging and documentation have to be set up. Non-branded units are available in smaller quantities, including at retail, so you can sample before committing. MOQ is negotiable and worth discussing against your specific order.
When should I place an order for a haze season?
In the quiet quarter before it. Production runs 25 to 45 days after sign-off plus 25 to 40 days sea freight to Southeast Asian ports, and Chinese New Year removes two to four weeks of production. Ordering when the readings spike means arriving as the event subsides, on air freight, at the worst time to be negotiating.
Is there demand in markets with good air quality?
Yes, and it is steadier than haze demand. Allergy and asthma management, airtight modern construction that traps indoor pollutants, institutional procurement by schools and clinics, and occasional deterioration from wildfires or still weather all drive purchases in clean-air markets. A distributor working only episodic markets has a volatile business.
How often do activated carbon filters need replacing in a haze market?
Much more often than the manual’s normal-conditions figure. Carbon saturates without any external sign, so it stops adsorbing while appearing fine, and haze loading exhausts it quickly. Hold replacement filter stock for the season: it is a second revenue stream when competitors are out of stock.
What is the HS code for air purifiers?
Generally HS 8421.39, filtering or purifying machinery and apparatus for gases. Digits beyond the first six are national, so confirm the full code and the duty rate for your destination rather than assuming the Chinese eight-digit code will be accepted as declared.
Should I choose OEM or ODM?
OEM for a first entry: existing tooling, short lead time, your branding on a proven design. ODM once volume justifies developing a product to your own specification. Starting with OEM and moving to ODM avoids committing to custom tooling before the market has been proven.
Reviewed by Maggie Shen, Director at Legom, on October 15, 2026. This article was reviewed for technical and commercial accuracy, including the distinction between the US HEPA definition and EN 1822 H13 and H14 classes measured at MPPS, the inability of HEPA media to remove gases and the resulting carbon requirement for smoke-affected markets, silent carbon saturation, the recurring nature of Southeast Asian haze episodes, air purifier minimum order quantities and lead times including the Chinese New Year shutdown, and the HS 8421.39 classification.