

Celrith's desktop air purifier filter is a cylindrical HEPA and granular activated carbon cartridge that captures fine particles while adsorbing formaldehyde, odours and other gaseous impurities in one part. It filters PM2.5, pollen, dust and other airborne particles, and is built for desktop and bedside mini air purifiers, car purifiers, fresh-air modules and humidifier-purifier units. It suits appliance brands and OEM/ODM buyers who need a compact cartridge matched to a specific airflow path. Celrith manufactures it in Zhongshan, Guangdong, China, with 100% flexible size and shape customisation.
Small purifiers sit close to the user — on a desk, a bedside table, a car console — so the air they move passes through a short, tight duct. The contaminants in that air are a mixed load: fine particulate such as PM2.5 and dust, pollen in season, and gases including formaldehyde and volatile organic compounds from furnishings and finishes. Odours are part of the same problem.
If the filter only addresses particles, the gases pass straight through. If it only addresses gases, the particulate load keeps building on whatever surface is available. Either way, the cartridge loads unevenly and the user notices a drop in airflow before the filter is genuinely spent. Desktop units make this worse because there is little room for a deep media bed, and a standard rectangular panel often does not fit the round or irregular duct at all.
When a cartridge is undersized or poorly matched to the duct, the fan has to work against higher resistance. Dust and pollen accumulate on the upstream face, airflow falls, and the motor runs longer to deliver the same perceived cleaning. In humid conditions, moisture can degrade untreated media and encourage odour inside the unit itself.
Gaseous contaminants add a different kind of load. Once a carbon layer is saturated, formaldehyde and odours are no longer held, and the unit can begin to release what it previously captured. For the appliance brand, the visible consequences are earlier replacement complaints, inconsistent performance between units, and a filter that cannot be sealed to the housing properly. Matching media grade, shape and airflow to the actual device is what keeps this load under control.
Celrith builds the cartridge as a two-in-one composite. A high-iodine-value granular coconut-shell activated carbon fill targets formaldehyde and odours, while the particulate layer uses high-precision PP polypropylene, moisture-resistant PP+PET composite, or PTFE high-efficiency microporous membrane. The thin composite structure frees space inside the housing, so the duct does not have to grow to accommodate filtration.
The carbon can be specified as standard high-iodine-value granular carbon or as a catalyst-modified grade developed for formaldehyde removal. Filtration grade is selectable from F7 to H13, chosen against the device airflow and the target cleaning performance rather than fixed in advance. Because the shape is open, the cartridge can be supplied as a conventional rectangular panel, a cylinder, or a sector and irregular polygon tailored to a small appliance.
Manufacturing is 100% flexible: length, width, thickness and foam sealing edge treatment are made to the customer's duct and structure dimensions. That is the contrast that matters — instead of forcing a device to accept a catalogue size, the filter is made to fit the device.
| Item | Detail |
|---|---|
| Product name | HEPA & Granular Activated Carbon Filter |
| Particulate media | High-precision PP polypropylene; moisture-resistant PP+PET composite; PTFE high-efficiency microporous membrane |
| Gas-phase media | High-iodine-value coconut-shell granular activated carbon; catalyst-modified activated carbon for formaldehyde removal |
| Particle filtration efficiency | HEPA grade selectable from F7 to H13, specified to the device airflow and purification requirement |
| Common forms | Rectangular flat panel, cylindrical, and sector or irregular polygon shapes for small appliances |
| Typical host devices | Desktop and bedside mini air purifiers, car air purifiers, fresh-air ventilation modules, humidifier-purifier units |
| Size customisation | 100% OEM/ODM flexible tooling; any length, width and thickness made to the customer's duct and structure, with foam sealing edge treatment |
| Quality system | ISO 9001, ISO 14001 and IATF 16949 quality management; factory quality controlled by a CNAS-accredited laboratory |
This filter is aimed at appliance brands and contract manufacturers building small-format air treatment products. Typical users include makers of desktop and bedside air purifiers, car purifier suppliers, fresh-air module integrators and humidifier-purifier manufacturers. It also suits buyers who need a replacement cartridge for an existing unit whose duct is round, sector-shaped or otherwise not served by a standard panel.
Because size and media grade are both open, the same product family covers projects from a first prototype through to series production. Brands that need a single cartridge to deliver both dust removal and formaldehyde/odour control are the clearest fit.
Celrith products are manufactured to meet REACH and RoHS environmental requirements, and compliance documents can be provided on request. The company holds ISO 9001, ISO 14001 and ISO 45001 system certifications, and added IATF 16949 automotive quality management certification in 2024.
The in-house laboratory is accredited by CNAS, the China National Accreditation Service for Conformity Assessment, and can issue test reports covering filtration efficiency, dust holding capacity and resistance. Production runs in a 50,000 m² plant, of which six cleanrooms account for 20,000 m², with IQC, IPQC and OQC controls across the process. With more than 20 years of filter development and manufacturing and over 1,000 filtration solutions developed, the company has exported to Europe, the United States, Japan and Korea for more than 20 years.
To quote accurately, please send your device or vehicle model, the required size or a drawing, the airflow or water flow the unit is designed for, the operating conditions, and your target quantity. Our team will respond with a specification proposal and pricing. Contact Celrith to start the conversation.
Celrith's desktop purifier filter combines a particulate layer with granular activated carbon. It captures PM2.5, dust and pollen, and adsorbs formaldehyde, volatile organic compounds and odours. The carbon is high-iodine-value coconut-shell granular carbon or a catalyst-modified grade for formaldehyde removal.
HEPA grade is selectable from F7 to H13 and is set against the device airflow and purification requirement. The grade is agreed per project rather than fixed for all units. Celrith's CNAS-accredited laboratory can issue efficiency, dust holding capacity and resistance reports.
Yes. Celrith supports 100% OEM/ODM flexible tooling, with any length, width and thickness made to your duct and structure dimensions, plus foam sealing edge treatment. Common forms include rectangular panels, cylinders, and sector or irregular polygon shapes for small appliances.
Send your device model, size or drawing, airflow, operating conditions and target quantity through the contact page. The team will propose a specification and price, then arrange a sample for evaluation. Sample terms are confirmed per project.
MOQ is set per project and depends on the size, media combination and whether new tooling is required. Share your target volume and Celrith will confirm the applicable minimum with the quotation. Flexible starting quantities can be discussed for new programmes.
Lead time depends on the customisation and order quantity, and is confirmed when the order is placed. Tooling, media procurement and sealing-edge processing all affect the schedule. Your quoted lead time will reflect the agreed specification.
Replacement depends on local air quality, daily run time and pollutant concentration, since the carbon saturates before the particulate media in many homes. Monitor airflow drop and odour breakthrough as practical signals. For series products, Celrith can discuss a dust holding capacity target matched to the device.
Yes. Size, shape, media grade and foam sealing edge treatment are made to your device, and branding can be discussed as part of the OEM/ODM brief. Send your dimensions and drawing to <a href="/en/contact">contact Celrith</a> to begin.